hey guys, happy new year... i have a 91 x 4x4 5-speed . it has a 3 inch. body lift and 2 skyjacker lift. i want 285/75/16 will they fit and do i have to change my gears

They should fit just fine. You won't need to regear, but you will get worse gas mileage and low end power. I fit 33s on my truck with a 4" lift with no trimming. Good luck.

A 285/75/16 is a load range D. Explorer's use a load range C. You could use these without problems, but they are a lot heavier and will make your ride a lot stiffer.

Can you expliain more about the load rating to me? Does a 265/75/16 have the same rating?

The load range has to do with how much weight a tire can hold. Explorers, and most small SUV's, use a load range C tire because it has relativly soft sidewalls for a comfortable ride. Bigger trucks, like and F-250 use load range D, and sometimes E tires to hold more weight. The load range is determined by how many plys the tire has. For example, a C is 2 ply, a D is 4 ply. My dad's new F-550 has load range G tires that have 14 plys. They are extremely stiff but the truck has a GVW of over 17,000 lbs.

I forgot. I know that Michelin LTX AT is a D, but I don't know about other brands. My dad had them o his F-250 for while so that I how I know.

It depends on the size, not the tire for load range. My Michelin LT26575R16 LTX AT tires are load range C, The LTX ATs come in load ranges from C-E according to their catalog for the LT version. They also make 3 P series sizes of the LTX ATs of a lower load range.

Your right. I remember seing a C 265-75. But I have never seen a 285/75 that was a C. My uncle and 2 of my cousins have them on there trucks (all of which are different brands) and 2 of them are D's and one is an E. So some tires have an option of load range, but the 285 is not a C.

Probably due to Michelin being considered more of a luxery type tire maker than an off-road tire maker. BFG TA KO in a 265 75R16 tire is a load range D as opposed to the LTX AT which is a load range C. I never noticed that before. It looks like if I do decide to go up to a 285 75R16 tire when my current ones wear out, I will have to get the load range D tire.

Going to the D is not bad as it can make up in stiffer sidewall what you lose in handling with a taller tire vs a shorter tire with a softer sidewall.
I went from 30" to 32" to 32.8 with the 285s and the 285s actually gave me better handling on the highway than the 30" tires did. Of course the 30" tires were Firestone Wilderness tires...
The 33x12.5x15s that I have been trying to cram under the truck are a little sloppier handling than the 285/75R16s.
Rick

Mine are Michelin LTX A/T 31x10.5-15 they have a load range of c and say the max load is 2250 and have 2 plie sidewall. I mean the load range from C to D shouldn't be all that noticeable. When i had my thornbirds ( they had a 6 plie sidewall and felt like 1/2 inch thick) the truck
felt the same except the damn vibration from the knobs. The ride was actually the same though.