Honda CR-V 5th gen: three wheels, one width, 0.15 in of variation

One width, three wheels, three aspect ratios

• 235/65R17 — 29.03 in, sidewall 6.01 in
• 235/60R18 — 29.10 in, sidewall 5.55 in
• 235/55R19 — 29.18 in, sidewall 5.09 in

Every one is 235 mm — 9.25 in — of section width. Each inch of wheel diameter is paid for with five points of aspect ratio, and the resulting spread across all three is 0.15 in, or 0.52%.

Read the sidewall column instead and the trim ladder becomes clear: 0.93 in of rubber separates the 17-inch fitment from the 19-inch one, on tires whose overall heights differ by a tenth of an inch. That is the entire trade, stated in one line.

Everything owners fit here is tiny

Two upgrade sizes are recorded, and both are modest by any standard:

• 245/65R17 at 29.54 in — +0.51 in, 1.76% from 235/65R17.
• 245/60R18 at 29.57 in — +0.47 in, 1.62% from 235/60R18.

Each is one width increment on the same wheel, holding the aspect ratio. Both add 0.39 in of section width and roughly a quarter of an inch of sidewall, and neither moves the speedometer enough to notice: an indicated 70 mph becomes 71.2.

There is no 33-inch equivalent on this page, and pretending otherwise would be dishonest. A unibody crossover with independent suspension, a low floor and wheel wells packaged around a 29-inch tire does not have room for a large change, and its owners do not attempt one.

What a 1.76% change actually delivers

Ride height at the axle rises by 0.26 in — half the diameter change — and the contact patch gets marginally wider and shorter. Rolling circumference goes from 91.2 in to 92.8 in, so the tire turns 682.8 times per mile instead of 694.8.

Those are real differences, and they are small. The reasons to make this change are tread pattern, compound and price, not geometry.

The one figure worth checking

Load index. The two upgrade sizes are wider, and width does not confer capacity — the casing standard and the reference inflation do. On a crossover routinely loaded with people and luggage, a substitution should carry at least the original's index at the placard's pressure, and the service descriptions printed after the size are where that is compared.

The load and speed index decoder converts both in a few seconds.

Winter tires are the change that suits this platform

Because the three factory sizes are within half a percent of each other, an owner on 18 or 19-inch wheels can move to the 17-inch factory size for a winter set and disturb nothing: −0.26% from the 18-inch fitment, −0.51% from the 19.

What that swap returns is sidewall — 0.46 in coming down from the 18, 0.93 in from the 19 — and access to a much larger catalogue at a lower price per tire. Winter compounds are produced in volume at 17 inches and sparsely at 19.

It also protects the expensive wheels through the season, which is the reason most people give and the one the arithmetic has nothing to say about.

What a blank ratio column means on a belt-driven transmission

Under 2%, the gearing consequence of any change here would be negligible whatever ratio were printed. It is also the wrong question for this vehicle: with a continuously variable transmission there is no discrete top gear to lengthen, so a taller tire does not push the engine down a step — it shifts the whole usable band a fraction and the transmission absorbs it without the driver being able to tell.

Where the arithmetic ends

None of it says a tire clears. On a unibody crossover the constraint is rarely the arch; it is the strut body at the top of the tire's inboard shoulder, and it does not move when you change the wheel. That is why the width figures on this page matter more than the diameter ones, and why the only useful measurement is taken at full lock on the vehicle itself.