---
title: Cessna 172M vs 172N vs 172P vs 172R vs 172S: The Five Skyhawks That Look the Same and Fly by Different Rules
url: https://zulucheck.com/blog/cessna-172m-vs-172n-vs-172p-vs-172r-vs-172s/
published: 2026-10-26
updated: 2026-10-26
publisher: ZuluCheck (https://zulucheck.com/)
---
# Cessna 172M vs 172N vs 172P vs 172R vs 172S: The Five Skyhawks That Look the Same and Fly by Different Rules

Park a 1975 Cessna 172M beside a 2026 Cessna 172S and most people at the airport won't see a difference. They have the same high wing, the same struts, the same tricycle gear, and the same four seats under the same tall glass.

Climb in and run the checklist from memory, though, and the airplane starts to disagree with you.

The 1975 airspeed indicator may be marked in **miles per hour**. One of the five has an engine that comes with an oil additive written into an Airworthiness Directive. Two of them extend their flaps to **40 degrees**, and the other three stop at 30. Two of them have no carburetor heat at all, because they have no carburetor. And the "big" 180-horsepower Skyhawk carries **less** with full tanks than a 1980s 172P.

This year marks 70 years of Cessna 172 production. Cessna introduced it in 1955, production began in 1956, and Textron says roughly **45,000 Skyhawks** have been delivered, more than any other airplane ever built. Most pilots learn in one, rent several, and switch between letters without thinking about it. This guide is for them. We went back to the original Cessna handbooks for the five Skyhawks you are most likely to fly today and compared what changed: history, engines, weights, CG envelopes, V-speeds, systems and, most importantly, **checklists**.

> **A note on sources.** Every number below comes from an original Cessna handbook unless we say otherwise: the 1975 *Model 172 and Skyhawk Owner's Manual* (172M), the 1978 *Skyhawk Model 172N POH*, the 1986 *Model 172P POH* (with the 1982 Information Manual), the *Model 172R Information Manual*, and the *172S Information Manual* (1998 original, revised to 2004) with the G1000 NAV III POH. Individual airplanes differ by model year, serial number, options and STCs. **Your airplane's own POH/AFM and weight-and-balance always win.**

---

## Key takeaways

- **The Cessna 172 Skyhawk** is a four-seat, single-engine, high-wing airplane, and the most-produced airplane in history: Textron says about 45,000 have been delivered since 1956.
- **172M (1973–1976):** 150-hp carbureted Lycoming O-320-E2D, 40° flaps, 14-volt electrics, 2,300 lb gross. The 1975 handbook gives airspeeds in miles per hour.
- **172N (1977–1980):** 160-hp O-320-H2AD, 28 volts from 1978, 40° flaps, 2,300 lb. The engine carries AD 80-04-03R2, which requires an oil additive and regular checks for metal.
- **172P (1981–1986):** 160-hp O-320-D2J, flaps cut to 30°, 2,400 lb, optional 62-gallon wet wing. Production then stopped for ten years.
- **172R (1996 to the early 2010s):** fuel-injected IO-360-L2A rated 160 hp at 2,400 rpm, 2,450 lb, 53 gallons usable.
- **172S (1998 to today):** the same engine at 180 hp and 2,700 rpm, 2,550 lb, best glide 68 KIAS, maneuvering speed 105 KIAS at gross, Garmin G1000 since 2005.
- **Useful load:** with full standard tanks, the book airplanes can carry from about 500 lb of people and bags (172R) to about 734 lb (172P).
- **Checklist traps:** carburetor heat exists only in the M, N and P; full flaps are 40° or 30°; the run-up limit is 125 or 150 rpm; the R and S cut fuel with a separate shutoff valve. Fly the checklist for your exact model.

## The short version: Cessna 172 models at a glance

| | **172M** | **172N** | **172P** | **172R** | **172S** |
|---|---|---|---|---|---|
| Marketing name | 172 / Skyhawk / Skyhawk II | Skyhawk / "Skyhawk/100" | Skyhawk P | Skyhawk R | Skyhawk SP |
| Model years | 1973–1976 | 1977–1980 | 1981–1986 | 1996–early 2010s | 1998–today |
| Built by Cessna (US) | 6,826 | 6,425 | 2,664 | – | still in production |
| Built by Reims (France) | 610 (F172M) | 525 (F172N) | 215 (F172P) | – | – |
| Engine | Lycoming O-320-E2D | Lycoming O-320-H2AD | Lycoming O-320-D2J | Lycoming IO-360-L2A | Lycoming IO-360-L2A |
| Power | 150 hp @ 2,700 rpm | 160 hp @ 2,700 rpm | 160 hp @ 2,700 rpm | 160 hp @ 2,400 rpm | 180 hp @ 2,700 rpm |
| Fuel delivery | Carburetor | Carburetor | Carburetor | Fuel injection | Fuel injection |
| Max flaps | 40° | 40° | 30° | 30° | 30° |
| Electrical | 14 V | 28 V | 28 V | 28 V | 28 V |
| Max takeoff weight | 2,300 lb | 2,300 lb | 2,400 lb | 2,450 lb | 2,550 lb |
| One-line personality | The 150-hp classic | The great climber with the infamous engine | The last of the "old" Skyhawks | The fuel-injected rebirth | The one Cessna still builds |
| Read the handbook | [1975 Owner's Manual](https://zulucheck.com/poh/cessna-172m.pdf) | [1978 POH](https://zulucheck.com/poh/cessna-172n.pdf) | [1982 Information Manual](https://zulucheck.com/poh/cessna-172p.pdf) | [172R Information Manual](https://zulucheck.com/poh/cessna-172r.pdf) | [172S Information Manual](https://zulucheck.com/poh/cessna-172s.pdf) · [G1000 (NAV III)](https://zulucheck.com/poh/cessna-172s-g1000.pdf) |

*Production figures from Wikipedia's Cessna 172 article, which cites Clarke and Phillips. The 172R's end date is fuzzy: VREF lists 1997–2012. Cessna's own 172S figures are not published by letter.*

---

## A 70-year story in five letters

### 172M (1973–1976): the "Camber-Lift" wing and the end of the MPH era

The 172M arrived for 1973 with the drooped "Camber-Lift" wing leading edge, which Cessna added to improve low-speed handling. That cuff is still on every Skyhawk built today. For 1974 Cessna added the **Skyhawk II**, a factory-equipped package with a second nav/com, ADF, transponder and nose-mounted dual landing lights, and enlarged the baggage compartment. For 1975 it added inertia-reel shoulder harnesses.

1976 was a turning point. Cessna dropped the plain "172" name and sold the airplane only as the Skyhawk, redesigned the panel with the engine and fuel gauges moved to the left where the pilot can see them, and switched the airspeed indicator from **miles per hour to knots**. If you fly a 172M, check which year it is: the V-speeds you remember may be in the wrong units.

The 172M is the last 172 designed for **80/87 octane** fuel. Its 150-hp Lycoming O-320-E2D is simple and well loved, and today most of them burn 100LL.

### 172N (1977–1980): 160 hp, 28 volts, and an engine with a reputation

The 172N "Skyhawk/100" got a 160-hp Lycoming **O-320-H2AD** designed for 100-octane fuel, hence the name. 1977 also brought a better flap control: the old spring-loaded toggle you had to hold down was replaced by a **lever with detents at 10° and 20°**. For 1978 the electrical system went from 14 to **28 volts** with a 60-amp alternator, and air conditioning became an option. For 1979 Cessna raised the flap speed for the first 10° from 85 to **110 knots**.

On paper the N is a star. In our comparison it has the **highest sea-level climb rate (770 fpm), the highest service ceiling (14,200 ft) and the shortest takeoff roll** of all five.

So why does its name come up so often at the fuel pump? The H2AD suffered **camshaft and tappet (lifter) spalling**. Lycoming revised the design three times: first a wider-lobe camshaft, then larger-diameter tappet bodies, which required a new crankcase. The FAA responded with a series of ADs. The best-known one, **AD 80-04-03R2**, applies to *all* O-320-H series engines. It requires adding one 6-ounce can of Lycoming **LW-16702** oil additive at every oil change or every 50 hours, whichever comes first, and inspecting the oil system for metal (suction screen, filter cut open) at least every 100 hours.

Many 172Ns flying today have been converted to other engines, often 160-hp O-320-D2Js or 180-hp conversions under STC. If you're looking at an N, find out **which engine is actually on the firewall**. That single fact changes the logbook, the maintenance budget and sometimes the POH supplement.

### 172P (1981–1986): fewer flaps, more weight, and a ten-year silence

The 172P put Cessna's fixes into production:

- **Engine:** the troubled H2AD was replaced by the 160-hp **O-320-D2J**.
- **Flaps:** maximum extension was cut from **40° to 30°**.
- **Weight:** gross weight went up **100 lb, to 2,400 lb**.
- **Fuel:** an optional "wet wing" with integral tanks raised usable fuel to **62 gallons**.

Later model years added more refinements. For 1982 the landing lights moved from the nose cowl to the wing leading edge, where the bulbs last longer. For 1984 Cessna added a second door-latch pin, a thicker windshield and windows, and low-vacuum warning lights.

Then everything stopped. Product-liability costs drove Cessna to suspend piston production in 1986, and the last P (134 built that year) was the last new Skyhawk for **a decade**. The [General Aviation Revitalization Act](https://www.congress.gov/bill/103rd-congress/senate-bill/1458) of August 1994 made a restart possible. In December 1994 Cessna chose Independence, Kansas, for a new single-engine factory.

### 172R (1996–early 2010s): the rebirth, now fuel injected

The new Skyhawk first flew on April 16, 1996, was certified that June and entered production in July. The first Independence-built airplane rolled out in November 1996 and went to an AOPA sweepstakes winner in January 1997.

The 172R was the first 172 with a factory fuel-injected engine: a Lycoming **IO-360-L2A** derated to **160 hp at only 2,400 rpm**, which makes it quiet and easy on the engine. It came with an annunciator panel, dual vacuum pumps, an avionics cooling fan, a separate **fuel shutoff valve**, an **auxiliary fuel pump**, 53 gallons usable and a 2,450 lb gross weight.

### 172S Skyhawk SP (1998–today): 180 hp and glass

Cessna announced the "Special Performance" 172S in 1998 and delivered the first one that July. It uses the same IO-360-L2A, but allowed to run to **2,700 rpm for 180 hp**, with a larger propeller and a **2,550 lb** gross weight.

The avionics kept changing. The Garmin **G1000** was announced for the Skyhawk in July 2004, and the R and S were certified with it in March 2005. The **G1000 NXi** arrived in January 2017. Garmin also offers an NXi retrofit for WAAS-equipped G1000 R and S models, since July 2019. Today's factory 172S comes with G1000 NXi and a GI 275 electronic standby, and offers the GFC 700 autopilot and Garmin ESP as options.

---

## Engines and fuel systems compared

| | **172M** | **172N** | **172P** | **172R** | **172S** |
|---|---|---|---|---|---|
| Engine | O-320-E2D | O-320-H2AD | O-320-D2J | IO-360-L2A | IO-360-L2A |
| Rated power | 150 hp / 2,700 | 160 hp / 2,700 | 160 hp / 2,700 | 160 hp / 2,400 | 180 hp / 2,700 |
| Minimum fuel grade | 80/87 | 100LL / 100 | 100LL / 100 | 100LL / 100 | 100LL / 100 |
| Oil sump (capacity / "don't fly below") | 8 qt / 6 qt | 6 qt / 4 qt | 7 qt / 5 qt | 8 qt / 5 qt | 8 qt / 5 qt |
| Standard fuel, total / usable | 42 / 38 gal | 43 / 40 gal | 43 / 40 gal | 56 / 53 gal | 56 / 53 gal |
| Optional tanks, usable | 48 gal (long range) | 50 gal (long range) | 50 gal (long range) or 62 gal (integral) | – | – |
| Carburetor heat | Yes | Yes | Yes | No | No |
| Priming | Manual primer | Manual primer | Manual primer | Electric aux pump + mixture | Electric aux pump + mixture |
| Fuel shutoff valve (separate) | No (selector has OFF) | No (selector has OFF) | No (selector has OFF) | Yes, push/pull | Yes, push/pull |

**Why the oil row matters:** a pilot used to the 172N's "4 quarts minimum" who preflights a 172S and finds 5.5 quarts may think it's plenty, but it's barely above the S's minimum. A 172M pilot sees 6 quarts as the floor. Same dipstick ritual, three different numbers.

**Why the fuel row matters:** the older selector has an OFF position. In the R and S the selector is BOTH / LEFT / RIGHT, and cutting fuel is done with a **separate red push/pull fuel shutoff valve**. That changes your engine-fire and forced-landing flows, as you'll see below.

---

## Weights and useful load: the 180-hp twist nobody expects

| | **172M** (Skyhawk) | **172N** (Skyhawk) | **172P** (Skyhawk) | **172R** | **172S** |
|---|---|---|---|---|---|
| Max ramp weight | – | – | 2,407 lb | 2,457 lb | 2,558 lb |
| Max takeoff weight | 2,300 lb | 2,300 lb | 2,400 lb | 2,450 lb | 2,550 lb |
| Utility category gross | 2,000 lb | 2,000 lb | 2,100 lb | 2,100 lb | 2,200 lb |
| Standard empty weight (book) | 1,350 lb | 1,393 lb | 1,433 lb | 1,639 lb | 1,663 lb |
| Useful load (book) | 950 lb | 907 lb | 974 lb | 818 lb | 895 lb |
| Weight of standard usable fuel (6 lb/gal) | 228 lb | 240 lb | 240 lb | 318 lb | 318 lb |
| **Left for people and bags, standard tanks full** | **~722 lb** | **~667 lb** | **~734 lb** | **~500 lb** | **~577 lb** |
| Baggage limits (all five) | 120 lb Area 1, 50 lb Area 2, 120 lb combined | ← | ← | ← | ← |

The book numbers say a **172P with full standard tanks can carry about 230 lb more people and bags than a 172R with full tanks**. That's a whole extra adult. The R does carry 13 more gallons, and you can always fly it with partial fuel, but the trend is real. The new-generation Skyhawks came out of the factory much heavier: the 172R's book empty weight is **206 lb more** than the 1986 172P's. Its extra 50 lb of gross weight only partly makes up for that.

Treat the table as a comparison of the factory brochure airplanes. Empty-weight definitions changed somewhat over the decades, and almost no 172 in service weighs what the book says, since 50 years of radios, paint and STCs add up. **Always use your airplane's actual weight-and-balance record.**

---

## CG limits compared: the heavier the Skyhawk, the smaller the sweet spot

All five measure CG from the same datum: the lower front face of the firewall. Here's how the envelope changes:

| | **172M** | **172N** | **172P** | **172R** | **172S** |
|---|---|---|---|---|---|
| Forward limit, ≤1,950 lb | ~35.0 in* | 35.0 in | 35.0 in | 35.0 in | 35.0 in |
| Forward limit at max weight | ~38.3 in* @ 2,300 | 38.5 in @ 2,300 | 39.5 in @ 2,400 | 40.0 in @ 2,450 | 41.0 in @ 2,550 |
| Aft limit (normal category) | ~47.0 in* | 47.3 in | 47.3 in | 47.3 in | 47.3 in |
| **CG range at max weight** | **~8.7 in*** | **8.8 in** | **7.8 in** | **7.3 in** | **6.3 in** |
| Utility category aft limit | ~40.8 in* | 40.5 in | 40.5 in | 40.5 in | 40.5 in |
| Utility category conditions | Rear seat and baggage empty | ← | ← | ← | ← |

\*The 1975 172M Owner's Manual prints its envelope only as a moment/1000 chart, with no inch limits or datum. These are read from the chart and are approximate.

The aft limit stayed at 47.3 inches for half a century. The forward limit at gross moved steadily aft as Cessna raised the weight, so **at maximum weight a 172S has about 30% less CG range than a 172N**. Put two big pilots up front in a 172S at gross and you can find the forward limit faster than you'd think. Do the math.

---

## Cessna 172 V-speeds compared (and the MPH trap)

| Speed | **172M** (1975, MPH CAS) | **172N** (1978, KIAS) | **172P** (KIAS) | **172R** (KIAS) | **172S** (KIAS) |
|---|---|---|---|---|---|
| Vne | 182 mph (~158 kt) | 160 | 158 | 163 | 163 |
| Vno | 145 mph (~126 kt) | 128 | 127 | 129 | 129 |
| Va at max weight | 112 mph (~97 kt) | 97 @ 2,300 lb | 99 @ 2,400 lb | 99 @ 2,450 lb | 105 @ 2,550 lb |
| Vfe | 100 mph (~87 kt), all flaps | 85 (all flaps; 1979+: 110 for 10°) | 110 for 10° / 85 for 10–30° | 110 / 85 | 110 / 85 |
| White arc starts (Vso) | 54 mph | 41 | 33 | 33 | 40 |
| Green arc starts (Vs1) | 61 mph | 47 | 44 | 44 | 48 |
| Vx (sea level) | – | 59 | 60 | 60 | 62 |
| Vy (sea level) | 91 mph (~79 kt) | 73 | 76 | 79 | 74 |
| Best glide | 80 mph restart / 75 mph forced landing | 65 | 65 | 65 | 68 |
| Short-field approach | ~70 mph (40° flaps) | 60 (40°) | 61 (30°) | 62 (30°) | 61 (30°) |
| Balked landing | 65 mph | 55 | 55 | 55 | 60 |
| Demonstrated crosswind | 15 kt | 15 kt | 15 kt | 15 kt | 15 kt |

What stands out:

- **The 1975 172M is in miles per hour, calibrated.** Its maneuvering speed is a single number (112 mph CAS) with no weight schedule. Later books give Va at several weights because Va *drops* as the airplane gets lighter. In a 172R at 1,600 lb it's just **82 KIAS**.
- **The 172S glides at 68, not 65.** Everyone "knows" the 172 best glide is 65 knots. For the M, N, P and R it is. For the S at 2,550 lb, it isn't.
- **The 172S has a *lower* Vy than the 172R** (74 vs 79 KIAS) even though it has more power.
- **Va went *up* in the S, to 105 KIAS**, because it's heavier. Rental pilots who brief "99" for every Skyhawk are wrong in the one they probably fly most often.

---

## Performance compared

| | **172M** | **172N** | **172P** | **172R** | **172S** |
|---|---|---|---|---|---|
| Top speed, sea level | 144 mph (~125 kt) | 125 kt | 123 kt* | 123 kt | 126 kt |
| Cruise | 138 mph (~120 kt), 75% @ 8,000 ft | 122 kt, 75% @ 8,000 ft | 120 kt*, 75% @ 8,000 ft | 122 kt, 80% @ 8,000 ft | 124 kt, 75% @ 8,500 ft |
| Sea-level rate of climb | 645 fpm | **770 fpm** | 700 fpm | 720 fpm | 730 fpm |
| Service ceiling | 13,100 ft | **14,200 ft** | 13,000 ft | 13,500 ft | 14,000 ft |
| Takeoff ground roll / over 50 ft | 865 / 1,525 ft | **805 / 1,440 ft** | 890 / 1,625 ft | 945 / 1,685 ft | 960 / 1,630 ft |
| Landing ground roll / over 50 ft | 520 / 1,250 ft | 520 / 1,250 ft | 540 / 1,280 ft | 550 / 1,295 ft | 575 / 1,335 ft |
| Book max range (best case) | 875 mi (~760 nm), 48 gal | 750 nm, 50 gal | 875 nm, 62 gal | 687 nm, 53 gal | 638 nm, 53 gal |

\*172P speeds include optional wheel fairings (about +2 kt).
*Range figures use Cessna's own assumptions, which changed over the years (power setting, altitude, reserves). Use them to compare like with like, not to plan a flight.*

Notice how close they all are. Forty years of development moved the cruise speed by only a few knots. What really changed was **weight, fuel capacity, systems and the cockpit**, and those are exactly the things that show up in the checklist.

---

## Systems and cockpit compared

| | **172M** | **172N** | **172P** | **172R** | **172S** |
|---|---|---|---|---|---|
| Flap control | Electric toggle, held down to extend, no preselect | Electric lever with 10°/20° detents | Lever with 10°/20° detents | Lever with 10°/20°/30° stops | Lever with 10°/20°/30° stops |
| Electrical system | 14 V, 12 V battery, split bus with automatic contactor, no avionics switch | 28 V, 60 A alternator, 24 V battery, **avionics power switch** | 28 V, 60 A, avionics power switch | 28 V, 60 A, avionics master | 28 V, 60 A, avionics master (split from 172S8704) |
| Voltage warning | Red HIGH VOLTAGE light (~16 V) | Over-voltage light (~31.5 V) | Red LOW VOLTAGE light | VOLTS annunciator (<24.5 V) | VOLTS (steam) / HIGH & LOW VOLTS (G1000) |
| Annunciator panel | – | – | Low-vacuum lights from 1984 | Low fuel L/R, oil pressure, vacuum L/R, volts | Same (steam); on the PFD (G1000) |
| Vacuum system | Single, suction gauge | Single, suction gauge | Single, suction gauge | **Dual vacuum pumps** | Dual (steam); single pump for standby attitude only (G1000) |
| Landing lights | Nose (Skyhawk II dual) | Nose | Wing leading edge from 1982 | Wing leading edge | Wing leading edge |
| Primary flight instruments | Steam gauges | Steam | Steam | Steam, or G1000 from 2005 | Steam, G1000 (2005), G1000 NXi (2017) |

---

## The part most articles skip: how the Cessna 172 checklists differ

This is where switching between Skyhawks catches pilots out. The flows *look* the same, and after a few hundred hours you stop reading and start reciting. Here's what changes from letter to letter, quoted from the handbooks.

### 1. The handbook itself changed

The 1975 172M came with an **Owner's Manual**. Section I is the checklist, and much of it is written as sentences: *"Check fuel selector valve handle on BOTH."* By the 1978 172N the book is a **Pilot's Operating Handbook** in the numbered-section format every Skyhawk since has used (limitations in Section 2, emergencies in 3, normal procedures in 4), with challenge-and-response checklists in knots. The R and S books add items the old ones never mentioned: *"Pilot's Operating Handbook: AVAILABLE in the airplane"*, *"Airplane Weight and Balance: CHECKED"* and *"Passenger Briefing: COMPLETE."*

### 2. Preflight: drains, oil and new switches

| Preflight item | **172M** | **172N** | **172P** | **172R / 172S** | **172S G1000** |
|---|---|---|---|---|---|
| Fuel drains in the checklist | Each wing sump + strainer knob ("about four seconds"); selector drain only if water found | Same as M | Wing sumps + **fuel selector quick-drain** + strainer knob ("at least four seconds, with fuel selector in each fuel tank position") | "Each sump location" on each wing + fuel strainer quick-drain under the fuselage; resample reservoir and selector if contaminated | Same as R/S |
| How much fuel to sample | "Small quantity" | "Small quantity" | "**At least a cupful**" (1986 POH) | "At least a cupful" from each sump | At least a cupful |
| Oil minimum | 6 qt | 4 qt | 5 qt | 5 qt | 5 qt |
| Avionics switch | None (automatic contactor) | "Avionics Power Switch: OFF" | Avionics power ON to hear the **cooling fan**, then OFF | Avionics master ON to hear the cooling fan, then OFF | BUS 1 and BUS 2 fans checked separately |
| Warning-light test | – | – | "**Low-Vacuum Warning Light: CHECK ON**" (1986 POH) | TST switch: all annunciators on | PFD shows OIL PRESSURE, LOW VACUUM, LOW VOLTS |
| Fuel shutoff valve | – | – | – | "**ON (push full in)**" | ON |

The number of sump drains on R and S models depends on serial number and fuel-system configuration. Learn **your** airplane's drain locations before you trust a list from memory.

### 3. Engine start: primer vs. fuel pump

Here are the two starts side by side, the way ZuluCheck shows them. Highlighted rows are the ones that differ.

**C172N checklist: Starting engine**

| # | Item | Action |
|---|---|---|
| 1 | Mixture | RICH |
| 2 | Carburetor Heat | COLD |
| 3 | Master Switch | ON |
| 4 | Prime | AS REQUIRED (2 to 6 strokes; none if engine is warm) |
| 5 | Throttle | OPEN 1/8 INCH |
| 6 | Propeller Area | CLEAR |
| 7 | Ignition Switch | START (release when engine starts) |
| 8 | Oil Pressure | CHECK |


**C172R checklist: Starting engine**

| # | Item | Action |
|---|---|---|
| 1 | Throttle | OPEN 1/4 INCH |
| 2 | Mixture | IDLE CUTOFF |
| 3 | Propeller Area | CLEAR |
| 4 | Master Switch | ON |
| 5 | Flashing Beacon | ON |
| | *If engine is warm, omit the priming steps 6, 7 and 8.* | |
| 6 | Auxiliary Fuel Pump | ON |
| 7 | Mixture | RICH, THEN CUTOFF (full rich until stable fuel flow (usually 3 to 5 seconds), then idle cutoff) |
| 8 | Auxiliary Fuel Pump | OFF |
| 9 | Ignition Switch | START (release when engine starts) |
| 10 | Mixture | ADVANCE (smoothly to RICH when engine starts) |
| 11 | Oil Pressure | CHECK |


The 172M and 172P start like the N. Flooded? In the M, N and P: mixture full lean, throttle full open, crank. In the R and S: aux pump off, mixture idle cutoff, throttle **½ to full**, crank. Hot start in the R: bring the mixture "promptly to 1/3 open."

**Glass (172S G1000)** adds steps before the start that no steam Skyhawk has:

**C172S G1000 checklist: Starting engine**

| # | Item | Action |
|---|---|---|
| 1 | Throttle Control | OPEN 1/4 INCH |
| 2 | Mixture Control | IDLE CUTOFF (pull full out) |
| 3 | STBY BATT Switch | TEST (hold for 20 seconds, verify that green TEST lamp does not go off) |
| 4 | STBY BATT Switch | ARM (verify that PFD comes on) |
| 5 | Engine Indicating System | CHECK (verify no red X's through ENGINE page indicators) |
| 6 | BUS E Volts | CHECK (verify 24 VOLTS minimum shown) |
| 7 | M BUS Volts | CHECK (verify 1.5 VOLTS or less shown) |


A carbureted pilot who starts an R with the mixture rich "like always" is likely to flood it. An R pilot who starts an N with the mixture at idle cutoff is going to be cranking for a long time.

### 4. Run-up

| | **M / N** | **P** | **R / S** | **S G1000** |
|---|---|---|---|---|
| Run-up rpm | 1,700 | 1,700 | **1,800** | 1,800 |
| Max magneto drop | 125 rpm | 125 rpm (1982 book) → **150 rpm (1986 POH)** | **150 rpm** | 150 rpm |
| Max difference between mags | 50 rpm | 50 rpm | 50 rpm | 50 rpm |
| Carburetor heat check | Yes, "for RPM drop" | Yes, "for RPM drop" | **None** | None |
| Other items | Suction gauge | Suction gauge; "Primer: IN and LOCKED" before run-up (1986) | Vacuum gauge, **annunciators clear**, check idle | Annunciators on PFD, GPS status page, autopilot preflight test |

A 140-rpm mag drop is within limits in a 172S, and in a 172P flown by its 1986 handbook. It's **over the limit** in a 172N. Even within one letter the book changed: the 172P's mag-drop limit went from 125 to 150 rpm between the 1982 and 1986 handbooks. That's why "it's a 172P" isn't enough. The checklist has to match **your airplane's** POH.

### 5. Takeoff flaps: "not recommended," then "not approved," then "preferred"

| | Normal takeoff | Short field / obstacle | What the handbook says |
|---|---|---|---|
| **172M** | Flaps **up** | Flaps **up**; 10° only for minimum ground run or soft fields | "Flap settings greater than 10° are **not recommended** at any time for take-off." |
| **172N** | Flaps **up** | Flaps **up**; 10° only for soft or rough fields | "Flap settings greater than 10° are **not approved** for takeoff." |
| **172P** | 0°–10° | **10°** | "Flap deflections greater than 10° are not approved for takeoff." |
| **172R** | 0°–10° | **10°** | Takeoff flap range 0°–10° |
| **172S** | 0°–10° | **10°** | Takeoff flap range 0°–10° |
| **172S G1000** | 0°–10°, **10° preferred** | **10°** | "Wing Flaps: UP – 10° (10° **preferred**)." |

Taking off with 10° in a 172N when the short-field checklist says flaps up, or with flaps up in a G1000 S when the book prefers 10°, isn't necessarily dangerous. It does mean your performance numbers come from a different chart.

### 6. Cruise and leaning

| | Cruise power | Leaning guidance |
|---|---|---|
| **172M** | 2,200–2,700 rpm, "no more than 75%" | Lean until rpm peaks and begins to fall off, then "enrichen slightly back to peak RPM" |
| **172N** | 2,200–2,700 rpm, no more than 75% | Lean until rpm "peaks and drops 25-50 RPM" |
| **172P** | 2,100–2,700 rpm, no more than 75% | "Mixture: LEAN"; also lean for max static rpm before takeoff from fields above 3,000 ft |
| **172R** | **2,000–2,400 rpm, no more than 80%** | By EGT: recommended lean is 50°F rich of peak; continuous lean-of-peak operation is **prohibited** |
| **172S** | 2,100–2,700 rpm, no more than 75% | By EGT, at 75% power or less |
| **172S G1000** | Same | Per-cylinder EGT with **LEAN ASSIST**; full rich above 75% |

The 172R is the odd one out. Its engine is derated, so its tachometer redline is 2,400 rpm. A pilot used to setting 2,500 for cruise in an older Skyhawk would be over redline in an R.

### 7. Descent and landing: carb heat and flaps

The M, N and P all have the same habit-forming line in *Before Landing*:

**C172N checklist: Before landing**

| # | Item | Action |
|---|---|---|
| 1 | Seats, Belts, Harnesses | SECURE |
| 2 | Fuel Selector Valve | BOTH |
| 3 | Mixture | RICH |
| 4 | Carburetor Heat | ON (apply full heat before closing throttle) |
| 5 | Autopilot (if installed) | OFF |
| 6 | Air Conditioner (if installed) | OFF |


**C172R checklist: Before landing**

| # | Item | Action |
|---|---|---|
| 1 | Pilot and Passenger Seat Backs | MOST UPRIGHT |
| 2 | Seats and Seat Belts | SECURED and LOCKED |
| 3 | Fuel Selector Valve | BOTH |
| 4 | Mixture | RICH |
| 5 | Landing/Taxi Lights | ON |
| 6 | Autopilot (if installed) | OFF |


(The 172P book says "before reducing power.")

The R and S have no carb heat to pull. That's fine until an R pilot gets into a rental N on a humid day, skips a line that isn't in their muscle memory, and finds out about carburetor ice on short final.

Then the flaps:
- **172M / 172N:** full flaps are **40°**. Short-field landings use "FULL DOWN (40°)," and forced landings say "40° recommended."
- **172P / R / S:** full flaps are **30°**. The P's forced-landing checklist says "30° recommended."
- **172N and 172P** carry a placard: ***"AVOID SLIPS WITH FLAPS EXTENDED."*** The M, R and S books advise that "steep slips should be avoided with flap settings greater than 20°" because the elevator can oscillate.

### 8. Balked landing (go-around)

**C172M · MPH checklist: Balked landing**

| # | Item | Action |
|---|---|---|
| 1 | Throttle | FULL |
| 2 | Carburetor Heat | COLD |
| 3 | Wing Flaps | 20° |
| 4 | Airspeed | 65 MPH |
| 5 | Wing Flaps | RETRACT (slowly) |


**C172N checklist: Balked landing**

| # | Item | Action |
|---|---|---|
| 1 | Throttle | FULL OPEN |
| 2 | Carburetor Heat | COLD |
| 3 | Wing Flaps | 20° (immediately) |
| 4 | Climb Speed | 55 KIAS |
| 5 | Wing Flaps | 10° (until obstacles are cleared) |
| 6 | Wing Flaps | RETRACT (after reaching a safe altitude and 60 KIAS) |


**C172P checklist: Balked landing**

| # | Item | Action |
|---|---|---|
| 1 | Throttle | FULL OPEN |
| 2 | Carburetor Heat | COLD |
| 3 | Wing Flaps | RETRACT TO 20° |
| 4 | Climb Speed | 55 KIAS |
| 5 | Wing Flaps | 10° (until obstacles are cleared) |
| 6 | Wing Flaps | RETRACT (after reaching a safe altitude and 60 KIAS) |


**C172R checklist: Balked landing**

| # | Item | Action |
|---|---|---|
| 1 | Throttle | FULL OPEN |
| 2 | Wing Flaps | RETRACT TO 20° |
| 3 | Climb Speed | 55 KIAS |
| 4 | Wing Flaps | 10° (until obstacles are cleared) |
| 5 | Wing Flaps | RETRACT (after reaching a safe altitude and 60 KIAS) |


**C172S checklist: Balked landing**

| # | Item | Action |
|---|---|---|
| 1 | Throttle | FULL OPEN |
| 2 | Wing Flaps | RETRACT TO 20° |
| 3 | Climb Speed | 60 KIAS |
| 4 | Wing Flaps | 10° (until obstacles are cleared) |
| 5 | Wing Flaps | RETRACT (after reaching a safe altitude and 65 KIAS) |


The 1982 172P book says "20° (immediately)", like the N. The 1986 book switched to the R's "retract to 20°" wording.

From 40° in a 172M or N, the first flap-up step does most of the work. From 30° in an R or S, it's a smaller step. Climb speeds differ by 5 knots between the R and the S.

### 9. Emergency checklists: the same emergencies, different handles

**Engine failure in flight (restart):**

**C172N checklist: Engine failure during flight**

| # | Item | Action |
|---|---|---|
| 1 | Airspeed | 65 KIAS |
| 2 | Carburetor Heat | ON |
| 3 | Fuel Selector Valve | BOTH |
| 4 | Mixture | RICH |
| 5 | Ignition Switch | BOTH (or START if propeller is stopped) |
| 6 | Primer | IN and LOCKED |


**C172R checklist: Engine failure during flight**

| # | Item | Action |
|---|---|---|
| 1 | Airspeed | 65 KIAS |
| 2 | Fuel Shutoff Valve | ON (push full in) |
| 3 | Fuel Selector Valve | BOTH |
| 4 | Auxiliary Fuel Pump | ON |
| 5 | Mixture | RICH (if restart has not occurred) |
| 6 | Ignition Switch | BOTH (or START if propeller is stopped) |
| 7 | Auxiliary Fuel Pump | OFF (back ON if fuel flow drops to zero (engine-driven pump failure)) |


The 172M glides at 80 mph for a restart and the 172S at **68 KIAS**. Everything else matches its family above.

**Engine fire in flight:**

**C172N checklist: Engine fire in flight**

| # | Item | Action |
|---|---|---|
| 1 | Mixture | IDLE CUT-OFF |
| 2 | Fuel Selector Valve | OFF |
| 3 | Master Switch | OFF |
| 4 | Cabin Heat and Air | OFF (except overhead vents) |
| 5 | Airspeed | 100 KIAS (if fire is not extinguished, increase glide speed to find an incombustible mixture) |
| 6 | Forced Landing | EXECUTE |


**C172S G1000 checklist: Engine fire in flight**

| # | Item | Action |
|---|---|---|
| 1 | Mixture Control | IDLE CUTOFF (pull full out) |
| 2 | FUEL SHUTOFF Valve | OFF (pull full out) |
| 3 | FUEL PUMP Switch | OFF |
| 4 | MASTER Switch (ALT and BAT) | OFF |
| 5 | Cabin Heat and Air | OFF (except overhead vents) |
| 6 | Airspeed | 100 KIAS (if fire is not extinguished, increase glide speed to find an incombustible mixture) |
| 7 | Forced Landing | EXECUTE |


The 172M uses **120 mph**. The 1986 172P book spells out the selector step as "**PUSH DOWN AND ROTATE TO OFF**": the OFF position is guarded, so you can't select it by accident. The G1000 S also adds **STBY BATT: OFF** to its engine-failure and forced-landing checklists. Otherwise the standby battery would keep powering the essential bus after you turn the master off.

**Fire during start:** keep cranking to suck the fire into the engine in every model. If it starts, run it for a few minutes at **1,700 rpm** (M, N, P, R) or **1,800 rpm** (S), then shut down and inspect.

**Checklists that exist in only some models:**
- **172M:** a caution about low fuel: with 1/8 tank or less, avoid a prolonged steep descent with partial power, full flaps and 80 mph or more.
- **172P / R / S:** *"Maximum slip or skid duration with one tank dry: 30 seconds."*
- **172R / S:** low-voltage (VOLTS) annunciator procedures, vacuum system failure, and icing guidance that mentions blocked "fuel injection air reference tubes" instead of carb ice.
- **172S G1000:** HIGH VOLTS / LOW VOLTS, standby battery operation ("for at least 30 minutes" on the essential bus), red-X **air data and AHRS failures** (go to the standby instruments), display cooling advisories, **excessive fuel vapor** (fuel pump ON, select opposite tank), and **high carbon monoxide (CO LVL)**.

**Securing the airplane:** the 1986 172P, R and S end with something 1970s pilots never did:

**C172R checklist: Securing airplane**

| # | Item | Action |
|---|---|---|
| 1 | Parking Brake | SET |
| 2 | Electrical Equipment, Autopilot | OFF |
| 3 | Avionics Master Switch | OFF |
| 4 | Mixture | IDLE CUT OFF (pulled full out) |
| 5 | Ignition Switch | OFF |
| 6 | Master Switch | OFF |
| 7 | Control Lock | INSTALL |
| 8 | Fuel Selector Valve | LEFT or RIGHT (to prevent cross feeding) |


### The checklist bottom line

Put it all together and a pilot rotating through a flight school's mixed fleet in one week could meet:

- **two airspeed units** (mph in an early 172M, knots in everything after),
- **three best-glide speeds** (80/75 mph, 65 KIAS, 68 KIAS),
- **two full-flap settings** (40° and 30°),
- **two run-up limits** (125 and 150 rpm),
- **two ways to cut the fuel** (selector OFF or shutoff valve pull),
- **three different oil minimums** (4, 5 and 6 quarts),
- and one airplane that wants you to test a standby battery before you've even started the engine.

None of this is hard on its own. **The danger is using the wrong one from memory.**

---

## So which Cessna 172 is "best"?

It depends on your mission and your budget. Here is what the data and handbooks suggest:

- **172M: best for simplicity.** 150 hp, 40° flaps, 14-volt electrics. It's the cheapest way into a Skyhawk, but it's an old airplane, so check the year (MPH vs knots), the panel and the logbooks.
- **172N: best performer on paper, but research the engine.** Highest climb rate and ceiling of the five, a 28-volt system and a nicer flap lever. Find out which engine is installed and how the H2AD ADs have been complied with, or whether the engine was replaced.
- **172P: best useful load of the classics.** More gross weight, a fixed engine and an optional 62-gallon wet wing for long legs. It was also built in the smallest numbers of the three classics, so good ones are hard to find.
- **172R: the gentle, modern trainer.** Fuel injection, quiet 2,400-rpm cruise, a modern interior and systems, but the lowest useful load with full fuel in this lineup.
- **172S: the one you'll rent most.** 180 hp, 2,550 lb, glass cockpit and still in production. Remember 68 knots and 105 knots, not 65 and 99.

Prices change constantly and depend heavily on engine time, avionics and damage history. Always get a pre-buy inspection from a mechanic who knows Skyhawks. This article is general information, not purchasing advice.

---

## The right checklist for *your* 172: ZuluCheck

If this article shows anything, it's that **"Cessna 172 checklist" isn't one checklist**. A 172N list in a 172S tells you to pull a carb heat knob that isn't there. A 172S list in a 172M gives you knots on an airspeed indicator marked in miles per hour.

That's why we built **[ZuluCheck](https://zulucheck.com/)**.

- **Model-specific Skyhawk lists, transcribed from the original handbooks.** ZuluCheck has a separate checklist for **every Skyhawk in this article**: the **172M** (from the 1975 Owner's Manual, in mph as printed), the **172N**, the **172P** (30° flaps and all, with Cessna's 172P Information Manual one tap away), the **172R**, the **172S** and the **172S G1000**. The app names the source document for every list, and you can open the source POH right in the app.
- **Your tail number, your numbers.** Customize any checklist per airplane, with your own V-speeds and frequencies. That 1976 172M in knots, the 172N with a 180-hp STC, the club 172P with the wet wing: each gets its own list.
- **One item at a time.** One tap per item and a big DONE button you can hit with your thumb in turbulence. Lists chain by phase of flight from preflight to shutdown, and you can skip an item and come back to it.
- **The V-speeds bar is always in view,** so it shows 68 in the S and 65 in the R.
- **Emergencies are one tap away.** A red Emergency button on every screen, with best glide on top and memory items first. Emergency checklists are **free for everyone**.
- **Hundreds of airplanes, and counting**, from Cessna, Piper and Beechcraft to Diamond, Cirrus, Tecnam and Van's, for when the flight school puts you in something other than a Skyhawk.
- **Built for the cockpit:** fully offline, no account, day/dark/night themes, phone or tablet in portrait or landscape. It also has an altimeter QNH converter with the nearest METAR, a landings counter and 90-day passenger currency reminders.

**ZuluCheck is free forever for two aircraft, with every feature included.** ZuluCheck Pro adds unlimited aircraft for clubs, rentals and that third airplane.

Load the checklist for the Skyhawk you're actually flying next:

Get ZuluCheck on [the App Store](https://apps.apple.com/app/id6822330794) and [Google Play](https://play.google.com/store/apps/details?id=com.snacksafe.zulucheck).

*ZuluCheck is for reference only and is not a substitute for the aircraft's approved Pilot's Operating Handbook / Airplane Flight Manual. Always verify every checklist against the POH for your specific aircraft.*

---

## Frequently asked questions

**What is the difference between a Cessna 172N and a 172P?**
The 172P (1981–1986) replaced the N's troubled 160-hp O-320-H2AD with the 160-hp O-320-D2J, reduced maximum flaps from 40° to 30°, raised gross weight from 2,300 to 2,400 lb, and offered optional integral tanks with 62 gallons usable. From 1982 its landing lights are in the wing instead of the nose.

**Why does the Cessna 172N have a bad reputation?**
Its Lycoming O-320-H2AD engine had camshaft and lifter spalling problems. AD 80-04-03R2 requires an LW-16702 oil additive at every oil change (at least every 50 hours) and oil-system inspections for metal at least every 100 hours. Many 172Ns have since been re-engined.

**What is the difference between a 172R and a 172S?**
Both use the fuel-injected Lycoming IO-360-L2A. The 172R is rated at 160 hp at 2,400 rpm with a 2,450 lb gross weight. The 172S makes 180 hp at 2,700 rpm, grosses 2,550 lb, and has different speeds, including a 68 KIAS best glide (65 in the R), a 105 KIAS maneuvering speed at gross (99 in the R), and a 74 KIAS Vy (79 in the R).

**Which Cessna 172 models have 40 degrees of flaps?**
Of the five in this guide, the 172M and 172N. Starting with the 172P, maximum flap extension is 30°.

**Do fuel-injected 172s have carburetor heat?**
No. The 172R and 172S have no carburetor, so there's no carb heat. They have an alternate air door instead, and their checklists use an auxiliary fuel pump and a separate fuel shutoff valve.

**Can a Cessna 172 carry four adults with full fuel?**
Rarely. Using factory brochure empty weights, people and bags with full standard tanks are limited to roughly 500 lb (172R) to 734 lb (172P). Real airplanes are usually heavier than the brochure. Do a weight-and-balance calculation every time.

**What is the best glide speed of a Cessna 172?**
65 KIAS for the 172N, 172P and 172R at maximum weight, and 68 KIAS for the 172S at 2,550 lb. The 1975 172M Owner's Manual gives 80 mph for a restart attempt and 75 mph with flaps up for a forced landing. Use the speed in your own airplane's handbook.

**How much fuel does a Cessna 172 hold?**
Usable fuel with standard tanks is 38 gallons in the 172M, 40 gallons in the 172N and 172P, and 53 gallons (of 56) in the 172R and 172S. Long-range tanks give 48 gallons usable in the M and 50 in the N and P, and the 172P's optional integral tanks give 62.

**What is the maximum takeoff weight of a Cessna 172?**
In the normal category: 2,300 lb for the 172M and 172N, 2,400 lb for the 172P, 2,450 lb for the 172R and 2,550 lb for the 172S. Many airplanes have STCs that change this, so check your airplane's weight-and-balance papers.

**Is the Cessna 172 still in production?**
Yes. The 172S Skyhawk is built in Independence, Kansas, with Garmin G1000 NXi avionics. Textron says about 45,000 Skyhawks have been delivered since 1956.

---

### Sources

- Cessna, *1975 Model 172 and Skyhawk Owner's Manual* (172M)
- Cessna, *Pilot's Operating Handbook, 1978 Skyhawk Model 172N* (D1109-1-13)
- Cessna, *1986 Model 172P Pilot's Operating Handbook and FAA Approved Airplane Flight Manual* (Original Issue, 2 September 1985): checklists, weights and performance. Also the *1982 Skyhawk Model 172P Information Manual* (through Revision 2, 1994) for limitations.
- Cessna, *Model 172R Information Manual* (172RIM, original issue 1996)
- Cessna, *Model 172S Information Manual* (original issue 1998, revised 2004), and *172S NAV III (G1000) POH/AFM*
- [Wikipedia: Cessna 172, variants and production figures](https://en.wikipedia.org/wiki/Cessna_172)
- [AOPA: 50th Anniversary of the 172 timeline](https://www.aopa.org/news-and-media/all-news/2006/june/pilot/50th-anniversary-of-the-172-(5))
- [AeroElectric: Cessna 172 Models and Differences (training manual excerpt)](http://www.aeroelectric.com/Reference_Docs/Cessna/cessna-misc/Cessna_C172-Model-History_RSV-Training-Manuals_2011.pdf)
- [CAA New Zealand: Lycoming O-320 Airworthiness Directive schedule (incl. FAA AD 80-04-03R2)](https://www.aviation.govt.nz/assets/aircraft/airworthiness-directives/engines/Lycoming-O-320.pdf)
- [General Aviation News: O-320-H2AD cam and tappet history](https://generalaviationnews.com/2024/04/01/what-should-i-do-with-an-engine-thats-making-metal/)
- [Textron Aviation: G1000 NXi for the piston line (2017)](https://media.txtav.com/194434-textron-aviation-brings-new-g1000-nxi-integrated-flight-deck-to-its-piston-product-line/)
- [Textron Aviation: Cessna Skyhawk specifications](https://cessna.txtav.com/en/piston/cessna-skyhawk)
- [Avi-Go: Cessna 172 marks 70 years, about 45,000 delivered](https://avi-go.com/news/articles/84942a231b057a3f562724fcbf47bffb)
- [VREF: What you should know about the Skyhawk 172 R–S](https://vref.com/news/what-you-should-know-about-cessnas-skyhawk-172-r-s/)