RV Tire Pressure Calculator: Motorhome Tire Pressure by Weight

A motorhome’s cold tire pressure comes from the tire maker’s load table, not the sidewall: weigh each end of each axle, take the heavier end, and set the whole axle to the lowest pressure that carries it. On Michelin’s own example — a coach on 275/80R22.5 tires — that is 95 psi front and 85 psi rear, and the heavier rear axle runs the lower pressure.

What pressure should my motorhome tires be?

The pressure your heaviest ends need — and nothing on the rig tells you that number without a scale. Michelin: “we recommend weighing each axle end separately and using the heaviest end weight to determine the axle’s cold inflation tire pressure.”

1. Weigh it loaded to travel. Michelin’s list is “passengers, food, clothing, fuel, water, propane, supplies”, plus anything you tow or carry on the back.
2. Weigh each end of each axle, not just each axle. RVSEF says it is “not uncommon for a difference of 1,000 pounds or more to exist between sides on the same axle”. A truck-stop scale gives you axles only.
3. Take the heavier end of each axle.
4. Find your tire’s table — by the markings on your sidewall, not just the size — and the single or dual column.
5. Read the lowest pressure whose load covers that end, and put it in every tire on the axle.
6. Never go past the wheel’s stamped maximum. If the table asks for more, the answer is less weight.

Michelin’s own worked example

Michelin’s RV tire guide works one coach through from the scale. It runs on 275/80R22.5 X Line Energy Z Load Range G tires, with corner weights of 5,400 lb left front, 5,175 lb right front, 8,500 lb on the left rear duals and 9,200 lb on the right.

Cold psi	Single, lb per end	Dual, lb per end
70	4,500	8,190
75	4,725	8,600
80	4,940	9,080
85	5,155	9,380 — rear
90	5,370	9,770
95	5,510 — front	10,140
100	5,780	10,520
105	5,980	10,880
110	6,175	11,350

Michelin’s RV table for 275/80R22.5 Load Range G, from its April 2025 inflation charts and May 2025 RV tire guide, which agree. Loads are per axle end.

Front: the heavier end is 5,400 lb. 5,370 at 90 psi falls short; 5,510 at 95 psi carries it — “a cold tire pressure of 95 PSI will support 5,510 lbs. on a single front tire.” Rear: the heavier end is 9,200 lb. 9,080 at 80 falls short; 9,380 at 85 carries it. So 95 psi front, 85 psi rear, and the right front and left rear duals end up, in Michelin’s word, “overinflated” for their own weight. That is the price of equal pressure across an axle, and Michelin pays it on purpose. The calculator’s defaults are this example, and it prints Michelin’s answer.

The trap in the tables: per axle end, not per tire

Arvee’s RV tire pressure guide mixes the two in consecutive steps. First: “Get your per-tire weight … divide each axle weight by the number of tires on that axle (2 for single, 4 for dually).” Then: “Find the weight row that meets or exceeds your heaviest axle-end measurement.” Follow the first step with Michelin’s example and the rear axle’s 17,700 lb becomes 4,425 lb a tire. Read against Michelin’s table, single column or dual, that seems to allow 70 psi — the lowest pressure it lists — at least 15 psi under Michelin’s own 85. On the calculator’s Class C case, LT225/75R16 duals with 4,500 lb on the heavier end, the per-tire figure read against the dual column lands 35 psi under.

You can check which convention a table uses on its own figures: the dual column at maximum pressure is exactly twice the per-tire dual load on the sidewall. For the 275/80R22.5 above that is 11,350 lb, against 5,675 lb a tire.

Same size, different table

Michelin’s instruction is to match the table to “your tire’s sidewall markings”, not just the size, and its own tables show why:

• 295/80R22.5 Load Range H has two Michelin tables. The XZA2 Energy reaches 7,830 lb single at 120 psi; the X Coach Z reaches 8,270 at 123.
• 225/75R16 comes as a C-metric tire (225/75R16C Load Range E, 3,195 lb at 83 psi) and as an LT tire (LT225/75R16 Load Range E, 2,680 lb). The numbers on the sidewall are nearly the same; the tables are not.

Two tables are left out of the calculator because Michelin’s own documents disagree about them. For the C-metric sizes, the May 2025 brochure’s “dual” row is per tire where the April 2025 chart’s is per axle end. For the X Coach Z, the sidewall dual figure contradicts its own dual column. If your tire is one of those, read its current table from Michelin directly.

The door placard, the sidewall and the table

Three numbers, and they answer different questions. RVSEF ranks them: “Tire Load Information - BEST, RV Dataplate - BETTER, Tire Sidewall Load Statement - GOOD”. The sidewall gives the maximum load at the maximum pressure. The table gives the pressure your actual load needs. The data plate is the RV maker’s recommendation, set without your scale weights.

On an LT225/75R16 Load Range E, the load stops rising at 80 psi (2,680 lb) in both Michelin documents, while its April chart gives the sidewall maximum as 90 psi and its May brochure gives 80 for the XPS RIB. Air above 80 carries nothing more on that tire.

Towing a trailer? Different rules

None of this applies to trailer ST tires. Lionshead — the supplier of every trailer tire in our records — says in its FAQ that “trailer tires should always be inflated to the maximum PSI indicated on the tire”. There is nothing to calculate. What a trailer owner can check is how old the tires are and how much of the warranty is left, which our tire age calculator works out from the DOT code. The other trailer number worth getting right is the one holding the wheel on: trailer lug nut torque is set by stud size rather than wheel size, and Dexter and Lippert do not publish the same figure for 9/16 inch studs.

Hot, cold, and the 5 psi rule

Across an axle, Michelin allows 5 psi of difference at most, and 2–3 psi when comparing tires hot. Its own example of a tire that has gone too far: with 80 psi recommended on a rear dual axle, one tire at 64 “is considered to be flat”, and both it and its partner come off for inspection — because “underinflation in a dual configuration overloads the properly inflated tire.”

Can your compressor reach it?

VIAIR sells its RV inflators by motorhome class, and says which is which. The 400P-RVS is named for “Class C motorhome, toy hauler, or camper van”; the 450P-RVS for “Class A and smaller RV’s”. Both are rated to 150 psi and to tires up to 275/80R22.5; what separates them is the duty cycle — 33% at 100 psi against 100% for up to an hour. For a tire larger than 275/80R22.5, such as a 295/80R22.5, VIAIR’s RV line states no rating at all, and the calculator says so rather than offering one.

Michelin also recommends “a truck tire pressure gauge with a dual angled head” for reaching inner duals. A tire pressure monitor, by contrast, is not chosen by pressure: TST’s 507 series reads to 218 psi and TireMinder’s i10 to 232, by their makers’ own specifications. And Michelin is clear that a monitor “should not be considered as a replacement for manual tire inspections”.

The two inflators compared

Model	VIAIR names it for	Max pressure	Duty cycle	Max tire size	Max draw	Buy
VIAIR 400P-RVS	"Class C motorhome, toy hauler, or camper van", per VIAIR	150 psi working pressure	33% at 100 psi	275/80R22.5	30 A	Check price(opens in a new tab)
VIAIR 450P-RVS	"Class A and smaller RV's", per VIAIR	150 psi working pressure	100% at 100 psi, for up to an hour at a time	275/80R22.5	23 A	Check price(opens in a new tab)

Where this goes wrong

1. Using the sidewall as the setting. It is a maximum. Your load decides the pressure, and air past what it needs buys a harsher ride.
2. Weighing axles, not ends. Averaging the two ends under-inflates the heavier one — 5 psi on both axles of Michelin’s own example.
3. Dividing duals by four. Michelin’s dual column is two tires’ load.
4. Reading another tire’s table. Match the sidewall markings, and note that Michelin prints two tables for one 295/80R22.5 size.
5. Bleeding hot tires. They read 10–15 psi high after driving.
6. Going past the wheel. Never exceed the stamped maximum — take weight off instead. To see what that weight is, our cargo capacity calculator shows what water and batteries weigh.

Questions worth answering