295/65R20 — an odd width on a heavy-duty wheel

Five vehicle records name 295/65R20 among their common upgrades, and four of them are three-quarter-ton pickups. It is not factory equipment anywhere in the catalogue.

A width that mostly does not get built

Metric section widths climb in 10 mm steps, but the truck market does not use all of them. On a 20-inch wheel this catalogue holds 265, 275, 285, 305 and 325 mm codes — and 295 exactly once, in this size.

11.61 in of section puts it between 285/65R20 at 11.22 in and 305/55R20 at 12.01 in, and closer to the first of those. That 0.39 in either side is the entire reason the width exists: it is what a manufacturer reaches for when 285 is not quite enough and 305 is more than the arch will take.

Just past a 35

Size	Diameter	Against 295/65R20	Section width
33x12.50R20	33.00 in	−2.10 in (5.98%)	12.50 in
285/65R20	34.59 in	−0.51 in	11.22 in
35x12.50R20	35.00 in	−0.10 in	12.50 in
295/65R20	35.10 in	—	11.61 in
325/60R20	35.35 in	+0.26 in	12.80 in
37x12.50R20	37.00 in	+1.90 in (5.42%)	12.50 in

Third row down is the notable one. This size stands a tenth of an inch taller than a flotation 35 while measuring 0.89 in narrower, so a truck fitted with these is running a taller tire than a set of 35s and a visibly slimmer one. Whether that reads as an advantage depends entirely on which of the two dimensions the buyer was after.

Where the four heavy-duty platforms start from

Those trucks leave the factory on 20-inch tires between 33.46 in and 34.07 in, so reaching this size is a change of roughly one to one and three-quarter inches — 1.63 in from 285/60R20 and 1.02 in from 275/65R20. Both are under five per cent.

That is a modest step by off-road standards, and it is the point of the size. A heavy-duty truck is already delivered on something close to a 34, so the useful upgrades are the ones that add an inch rather than three. What a change of that scale does to the driveline is worked through in the axle ratio basics reference.