BFGoodrich??
Fitter
. Others here have posted getting 40-50K miles out of them. I run them in 33x12.50-16.5 size on my stock suspension '92 F350 4x4 and they fit nicely with no rubbing once I spaced the front bumper forward about 2 inches. I run them on 10" wide wheels and they fit very nicely on the wheels.
On the metric sizes:
a stock 265/75-16 is ~31.5" x 10.5" (same dia as 235/85-16's but wider),
a 285/75-16 is ~32.8" x 11.25",
a 295/75-16 is ~33.5" x 11.5"
a 305/75-16 is ~34" x 12"
and a 315/75-16 is ~34.5" x 12.5"
(these are approx sizes rounded to the nearest 1/4-inch)
Tire diameter has a big effect on overall gear ratio. Changing to a tire that is too much bigger than stock while leaving the axle gearing stock can cause a noticeable lack of power and the trans will want to downshift out of OD alot more. It's also bad for gas mileage and wears out an auto tranny quicker. Find out what gear ratio your truck has and let that be your guide to how tall a tire to run on the truck, if you are not interested in changing the gears.
Gear changes are not cheap on a 4x4 since both axles' gears need to be changed. The gear change on my 4x4 truck was $1800 with a rear locker and installation.
Depending on your current gear ratio and engine/tranny combo, a 285/75-16 or 33x12.50-16 tire is usually ok with stock gearing on a truck that originally came with 265/75-16's or 235/85-16's as long as the truck was not geared high (numerically low, aka 3.55 gears) already from the factory.
33" tires work well with 4.10 gears and 35" tires work well with 4.56 gears. I run 33's with 4.56's (truck originally had 3.55's with 235/85-16's) because I have a small engine (351) in a heavy truck (6500 lbs unloaded) and it needed lower gears for towing/hillclimbing power since I live in an area with alot of hills. The low gears help off-road as well.
To find your axle ratio and differential type (ltd slip or open), look on your door sticker for the axle code and look up the code in the 'tech articles' section of this site under the 'decoders' section for axles.
[EDIT: your late model truck's axle code may not be on that list above. I would call the dealer and have them look it up or look on your window sticker to see if the ratio is listed there, or post a question about it in the Superduty forum and someone there may know what the code is means.]
Last edited by SoCalDesertRider; Jul 10, 2004 at 10:26 AM.


