Alright guys, I just had 285/75/16 BFG TA KO's Installed on my stock rims (Will have picks soon). I love the look, really finishes off the truck. Didn't need to, but cranked up the torsion bars and front end sits a bit taller as well (no lift).

Here is the question, since this isn't my cup....

I do notice a little bit of bottom end power loss, but not much, going from the stock badyear 255/70/16. Is there any harm in not regearing? What will the overall benefits be? And what gears would you recommend? I have an '02 5.4L 4x4 with a 3.55 rear end.

Thanks!

 

Outdoorsman,

I wouldn't think there would be any "felt" difference in power. You didn't really get a much "taller" tire by moving up from a "70" to a "75". You did widen your footprint; however, the width of a tire doesn't effect your overall drive ratio. The weight difference between the tires is probably only about 20lbs each. If you do a considerable amount of towing, or you tow long distances when you tow in-frequently, i'd go up to a 3.73 rear. Keep in mind, your gas mileage will probably suffer 1 to 2 mpg by the change in Gear Ratio.

Good luck and congrats on a great set of tires!

Sackett

 

Well..........not quite. You did gain a fair amount of height from the tire change. Keep in mind that just going from a 70 to 75 series tire doesn't make much difference by itself. The 70 is the sidewall height as a percentage of the width. In this case you're going form 255mm * 0.70 = 178.5mm sidwall height. Then take that times 2 (you have 2 sidewalls) then add the rim height. A 285/75/16 would be (285mm * 0.75)2 + 16 = 32.8". If you were comparing a 265/75/16 to a 265/70/16 you're right it wouldn't make much difference at all, but in this case there is a much wider tread width so the sidewalls increase proportionally. You effectively went from a 31+ to a 33" tire. That 2" does not seem like much, but to your transmission it does. I ran 33s on my 4R70W trans for awhile until I put 35s on. I was suprised at how much the 33s had weakend it because the 35s finished it off in less than 1 month. My recommendation would be to regear to 4.10s (3.73s wouldn't be quite enough).