Nissan Frontier (D40): the 75-series trim starts an inch ahead of the others

Three sizes, two clusters

265/70R16 computes to 30.61 in and 265/65R17 to 30.56 in — 0.04 in apart, on different wheels, which is a manufacturer holding rolling diameter constant while the wheel grows an inch.

265/75R16 breaks the pattern at 31.65 in. Same 265 mm width, same 16-inch wheel as the first, five more points of aspect ratio, and 1.04 in more diameter. A 3.41% difference from a change in one digit of the size code.

Over a production run from 2005 to 2021 that is the size to identify before doing any arithmetic about your own truck.

What a nominal 33 costs, from each start

33x12.50R16 measures 33.00 in:

• From 265/75R16: +1.35 in, 4.27%.
• From 265/70R16: +2.39 in, 7.82%.
• From 265/65R17: +2.44 in, 7.97%.

The 75-series trim is making barely half the proportional change the others are, to the same tire. At 4.27%, an indicated 70 mph is 73.0; at 7.97% it is 75.6.

Section width tells a second story. The flotation tire adds 2.07 in across from any of the 265-width starting points — considerably more than it adds in radius, and on a midsize truck the inner fender usually notices the width first.

The metric alternative and what it trades

285/75R16 at 32.83 in reaches almost the same height as the flotation 33 while adding only 0.79 in of width. From 265/75R16 it is +1.18 in, a 3.73% change; from 265/70R16, +2.22 in and 7.27%.

It is the classic narrow-and-tall answer on a 16-inch wheel, and the reason 16-inch wheels have stayed on this platform long after the industry moved upward. 285/70R17 does the same job at 32.71 in for owners on the 17-inch fitment.

The ratio column is empty, across seventeen model years

Nothing above is touched by that: it is all geometry. The blank is still worth noticing on this truck specifically, because a model that ran essentially unchanged from the mid-2000s to the early 2020s accumulated engine, gearbox and axle variations along the way, and one printed ratio would have covered a fraction of them.

The general relationship still applies whatever ratio your truck carries: a 7.82% diameter increase behaves exactly like a 7.82% numerically lower final drive — 7.82% less torque reaching the road, and 7.82% fewer engine revolutions for the same distance. With a ratio in hand, the gear ratio calculator returns the figure that restores it.

Two decades of variants under one record

A platform sold across seventeen model years accumulates trim, cab and market variations, and the recorded wheel diameters for this one include an 18-inch option with no 18-inch tire size confirmed against it. That gap is stated rather than filled — an unconfirmed size printed alongside three confirmed ones would be indistinguishable from them.

For your specific truck the door placard settles the question completely, including the pressures its load ratings were set against.

What a tire loses to its own tread

There is a second effect worth naming on a platform this old, and it has nothing to do with which size was fitted. Tread depth is part of rolling radius, and it is consumed.

An all-terrain tire that starts with 16/32 in of tread and is replaced at 4/32 in has lost 0.375 in per side — 0.75 in of overall diameter over its life. On a truck whose factory sizes sit around 30.6 in, that is a 2.4% drift, in the same direction and of the same order as some of the size differences above.

It means a speedometer correction calculated on new tires slowly undoes itself, and that two trucks wearing the same size code can measure noticeably differently depending on how much of the tread is left.

The boundary of the arithmetic

Nothing here says a tire clears. Front-end packaging on this platform is tight, and what contacts first is usually the inner edge of the front tire against the frame or the lower arm at full lock. That is a width-and-offset problem rather than a diameter one, which is why the 2.07 in the flotation tire adds across matters more here than the 2.39 in it adds in height, even though the height is what gets talked about.