Just got my BFG 255/85R16 M/Ts mounted. They look great, and fit perfectly with no lift. I may crank the torsion bars jsut a bit to level the truck out, but it doesn't look like I *have* to do it. Just went out and played in the snow drifts and these things are great. Much much more traction than the crapp General Graber AWs that came on the truck.

I don't have a speedo gear yet since I haven't felt like crawling underneath in the snow . I'm going out with a GPS this afternnon and see how far off the speedo is, should be about 14% low, by my calculations.

Jay

------------------
1998 F150 Lariat 4x4 Extended Cab. 4.6L Auto
Mods: Superchip
Airforce One
BFG 255/85R16 M/Ts
Planned: Ravin Z-55

 

Is the 255 85R wider then the 255 70R? I hate the metric system!

 

I'm going to have to defend the metric system a) because I grew up with it and b) because it's easier and makes much more sense than the English system. Doctors and engineers I'd bet will agree with me.

But to answer your question which by the way has nothing to do with either metric or standard system, both tires are exactly the same width: 255 milimeters or 25.5 centimeters or .255 meters. The only difference on the sizes you're asking about it the height of the shoulder. First case the shoulder is 85% the width of the tire or 216 milimeters (or 21.6 centimeters or .216 meters). The second one is 70% the width of the tire or 178 milimeters, etc, etc.

Sorry for the long answer to your short question.

 

OOH, I see your point. The metric system is much better than 31 inch high and 10.5 wide. But you are right about the metic system and medicine, it is the way to go. I just don't understand it with tire size. I did some research and found that the 85R indeed has nothing to do with width.

 

Yeah, they're the same width, 3" taller. Perfect fit on the stock rims. And they do a great job in snow .

Speedo is about 11.5% off.

Jay