Toyota Camry 8th gen: four wheel sizes, and the 16-inch tire is the tallest

The range, in order of height

• 205/65R16 — 26.49 in, sidewall 5.25 in
• 235/40R19 — 26.40 in, sidewall 3.70 in
• 235/45R18 — 26.33 in, sidewall 4.16 in
• 215/55R17 — 26.31 in, sidewall 4.66 in

Total spread: 0.18 in, or 0.69%. Four wheel diameters from 16 to 19 inches, and the rolling diameter barely moves — which is what allows one speedometer calibration and one set of gear ratios to serve the whole model range.

The base 16-inch fitment is the tallest of the four and carries 1.55 in more sidewall than the 19-inch one, on a tire that is 30 mm narrower.

Both recorded upgrades reduce diameter

225/50R17 at 25.86 in and 245/40R18 at 25.72 in are the two sizes commonly fitted, and every comparison with a factory size is negative:

From	To 225/50R17	To 245/40R18
205/65R16	−2.39%	−2.93%
215/55R17	−1.72%	−2.26%
235/45R18	−1.78%	−2.32%
235/40R19	−2.06%	−2.59%

These are wider tires with shorter sidewalls, chosen for steering response and appearance, and the diameter is what pays for them. At −2.93% an indicated 70 mph is 68.0 and the odometer over-counts: 100 indicated miles is 97.1 actually travelled.

An over-reading speedometer is the less familiar case

Manufacturers deliberately bias speedometers to read slightly high, so that production variation and tire wear can never push the reading below true speed. A shorter tire pushes the same direction and increases that bias.

Nothing about that is dangerous, and the practical effects are bookkeeping: service intervals arrive sooner in real distance than the display says, and fuel economy computed from indicated miles understates the car's actual figure.

What the trade actually is

215/55R17 to 225/50R17: 0.39 in more section width, 0.23 in less sidewall, 0.45 in less diameter. The tire turns 779.9 times per mile instead of 766.5.

On a family sedan those are small numbers, and the honest summary is that the difference is felt in steering response and impact harshness rather than in anything a calculator can express.

The 16-inch fitment is the one to keep for winter

Owners of the 18 and 19-inch trims looking for a second set have an unusually good option in their own model range: the base 205/65R16 is 0.63% taller than 235/45R18 and 0.34% taller than 235/40R19, which is no change at all in practical terms.

What it brings is 5.25 in of sidewall against 4.16 or 3.70, a 30 mm narrower tread — which is generally the direction you want in snow — and the cheapest wheel and tire combination the platform was ever sold with.

The constraint is mechanical rather than arithmetic: a 16-inch wheel has to clear the brakes, and on the higher trims of a range like this the front discs are sometimes larger than the base car's. That is measured, not calculated.

Four sizes, one calibration

It is worth noticing what holding four fitments inside 0.69% actually achieves. One speedometer calibration, one set of gear ratios, one anti-lock brake configuration and one set of stability control constants serve every trim, from the 16-inch base to the 19-inch sport package.

It also sets a useful reference for anything fitted afterwards: the manufacturer itself never varied rolling diameter by more than seven tenths of a percent across the range.

The ratio column, on a car where it may not mean anything

At changes of under 3% the gearing consequence is negligible whatever ratio applies. On the hybrid versions the question dissolves entirely: engine speed there is set by a planetary power split between two motors and the engine, so the crankshaft is not tied to road speed by a fixed multiplier at all, and a taller tire changes what the wheels do without dictating what the engine does.

Where geometry runs out

Brake clearance behind the rim, casing-to-liner room with the wheel turned, and the placard's load figure are all questions about the car in your driveway rather than the model. Both sizes commonly fitted here are shorter and wider than anything the factory used, which is the one combination where the load index is worth checking twice: a lower-profile casing on the same rim diameter is not obliged to carry what the taller one did.