Toyota Tundra 3rd gen: the 22-inch wheel carries the shortest tire

The wheel diameter and the tire diameter run in opposite directions

Four factory sizes are recorded, and reading them in wheel order is instructive:

Size	Wheel	Overall diameter
245/75R18	18 in	32.47 in
265/70R18	18 in	32.61 in
265/60R20	20 in	32.52 in
285/45R22	22 in	32.10 in

The tallest fitment sits on the smallest wheel and the shortest on the largest. The total spread is 0.51 in, which is the manufacturer holding rolling diameter roughly constant across the trim range while the wheels grow four inches — but not holding it perfectly.

That 1.58% gap between the 18-inch 265/70R18 and the 22-inch 285/45R22 is real. Two trims of the same truck read slightly differently at the same road speed.

Which starting point you have decides the size of the step

LT285/70R18 at 33.71 in is the modest move on this platform:

• From 265/70R18: +1.10 in, 3.38%.
• From 245/75R18: +1.24 in, 3.82%.
• From 285/45R22: +1.61 in, 5.02% — the largest change to the same tire, because the starting point was the shortest.

For the 35-inch sizes the pattern repeats and amplifies. LT295/65R20 at 35.10 in is +2.49 in from the 18-inch 265/70R18 and +3.00 in, 9.35% from the 22-inch fitment.

The 22-inch trim has the most to think about

Section width is identical between 285/45R22 and LT285/70R18 — both are 285 mm, 11.22 in — so the step from one to the other adds 1.61 in of height and nothing at all across. That is a rare clean single-variable change, and it is available only from the 22-inch starting point.

What it costs is sidewall in the opposite direction from where you might expect: the 22-inch tire has 5.05 in of sidewall, and the 18-inch replacement has 7.85 in. Nearly three inches more rubber between the rim and the road, on a wheel four inches smaller in diameter.

Owners moving off 22s are usually buying that sidewall rather than the height. The height comes along with it.

Wheels swap between trims almost for free

Because the four factory sizes are held inside 1.58% of each other, a set of wheels and tires from one trim of this generation fitted to another barely disturbs the arithmetic. Moving from the 22-inch fitment to the 18-inch 265/70R18 is a 1.58% increase in rolling diameter — smaller than the difference between those tires new and half worn.

That is why used take-off sets circulate so freely on this platform. The constraints that remain are mechanical rather than arithmetic: brake caliper clearance behind the smaller wheel, offset, and whether the tire pressure sensors are compatible and can be relearned.

What is not recorded here

The axle ratio column is empty for this generation. That is the field a reader chasing engine speed wants most, and it is also the one this platform makes hardest to state in a single number: the generation replaced a V8 with a turbocharged six and added a hybrid version of it, and the gearing belongs to the powertrain rather than to the badge on the tailgate.

The consequence for the arithmetic above is nil: diameter, width, sidewall and speedometer error need no ratio. Only the engine-speed question does, and the gear ratio calculator will answer it if you supply the ratio your own truck carries.

Practical arithmetic, not permission

A 9.35% diameter increase is a 9.35% reduction in torque at the road and a 9.35% under-reading speedometer, on any vehicle, in any driveway. Whether the tire clears this truck's wheel wells, liners and suspension at full lock is a separate question that the size code cannot answer and this page does not attempt to. The 22-inch trim is the interesting case: its owners are the ones for whom every step listed here also means buying wheels, and a wheel change moves offset, which moves the contact point the arithmetic never sees.