I think 265/75R16s look excellent on a stock 4Runner, but they are too small if you have any kind of a lift. Here's mine with a 7 year old Tundra/OME lift and 265/75R16 BFG AT KO's. My friend's truck with the same lift but 7 years newer (no sag) has even larger fender openings:
There is simply too much wheelwell.
That said, fuel economy is really important to me and I'm unwilling to move to a 285. So I bought some 17" Tundra/Sequoia wheels, which will allow me to run 275/70R17 tires.
Here are some stats for comparison, all using BFG AT KO:
265/70R16 - 10.6" wide, 30.7" tall
265/75R16 - 10.5" wide, 31.7" tall
275/70R17 - 11.0" wide, 32.2" tall
285/75R16 - 11.4" wide, 32.8" tall
I think it's the best of both worlds, exactly inbetween the 265 and 285 in both height and width, which is exactly what my truck needs. A 5-speed 4Runner with 4.10 gearing runs 400 RPMs higher on the highway than an automatic, negatively affecting highway MPGs. In a
recent thread I posted my mileage results caravaning with three other 3rd gens, all similarly built. The two 5-speed trucks actually got lower fuel economy on the highway than the two autos due to the 400 RPM difference in final gearing. So I think a small change in tire size (without going too much wider) may help mileage for the guy with the manual transmission.
Work in progress, 17" Tundra/Sequoia wheels in graphite gray:
And yes, those old tires are going away.