Toyota Land Cruiser (200 Series): two factory sizes, one width

The narrowest factory range here

Two sizes are recorded: 285/60R18 at 31.46 in and 285/50R20 at 31.22 in. Both are 285 mm — 11.22 in — of section width. The difference between them is 0.24 in of diameter, or 0.78%, and 1.12 in of sidewall.

That is an unusually clean comparison. The manufacturer chose one width for the vehicle and then offered two ways to package it: more sidewall on a smaller wheel, or less on a larger one, at essentially the same rolling height.

Why this platform's arithmetic is about load, not diameter

The 200 Series is heavy — substantially heavier than the midsize SUVs it shares showroom space with — and it was sold with a genuine towing and payload brief. The consequence for tires is that the load index on the placard is doing real work, and a substitution that clears geometrically can still fall short of the figure the vehicle was certified with.

That is why the light-truck option below matters more here than the extra height it brings.

Three steps, and one of them changes nothing across

285/65R18 at 32.59 in is the natural move from the 18-inch fitment: +1.12 in of height, 3.57%, and exactly zero change in section width. One aspect-ratio step, 0.56 in more sidewall, nothing added toward the suspension or the liner.

33x12.50R18 at 33.00 in adds +1.54 in of height from the same start — and 1.28 in of width, which is the number to watch. On a vehicle with full-time four-wheel drive and a substantial front axle assembly, that width is where the packaging gets interesting.

LT295/70R18 at 34.26 in is the largest of the three: +2.80 in, 8.88%, only 0.39 in wider than the factory tire, and built to the light-truck standard. An indicated 70 mph becomes 76.2, and 100 miles of odometer is 108.9 covered.

From the 20-inch fitment

Every step is slightly larger, because the starting diameter is 0.24 in shorter:

• 285/65R18 — +1.37 in, 4.38%
• 33x12.50R18 — +1.78 in, 5.70%
• LT295/70R18 — +3.04 in, 9.74%

All three involve changing wheels as well as tires, since none of them is an available 20-inch size. For an owner on 20s the wheel change is the price of entry, and it brings the sidewall back with it.

The ratio column, and a market-by-market caution

Nothing above depends on a ratio; engine speed after a change does. The field is empty here, and this platform is one where an unsourced figure would be especially easy to get wrong: the same vehicle was sold under different names in different markets, with petrol and diesel engines that were never offered side by side, and the gearing followed the engine rather than the badge.

A 8.88% diameter increase behaves like an 8.88% numerically lower final drive whatever that ratio turns out to be — reducing torque at the road by the same fraction on a vehicle that is already asking a lot of its driveline when loaded.

The spare is part of the calculation

This platform carries a full-size spare, and on a vehicle with full-time four-wheel drive and a centre differential, a spare of a different rolling diameter is not a neutral object. A mismatch in circumference between the spare and the other three produces continuous differential action for as long as it is fitted.

That makes the fifth tire part of the cost of any size change here, rather than an afterthought — and it makes the physical dimensions of the spare carrier a constraint alongside the wheel wells. A LT295/70R18 is 2.80 in taller and 0.39 in wider than the tire the carrier was designed around.

Where this page stops

It does not say a tire fits. Clearance depends on suspension, on the specific model year's bodywork, and on how far the steering turns; load capacity depends on the placard and the tire's own rating. On a vehicle this heavy the second of those is not a formality — a full-size body-on-frame wagon asks more of four tires than its footprint suggests, and the placard's figure is the one that has to be met before the arch clearance is even interesting.