99 150 4x4 switching from 255's to 265 on stock 16's good idea or is it gonna throw me out to lunch? help please

 

it'll fill up the wells some more

Your stock size I assume:

255/70-16
d=30.06
w=7.03

The 265's i assume:

265/75-16
d=31.65
w=7.82

Your '99 will need it's computer re-programmed (digital odometer, right ?) for the larger diamater wheel/tire combo. You can either take it to a dealer or buy yourself a micro-tuner.

 

What is the exact current and new size? If as listed above, then you would be off by about 11% which is significant and I'd get the speedo adjusted.

 

thanks for the info was thinking about alittle more meat on the road but its not that big a deal

 

I went from 255/70-16 Generals to 265/70-16 Michelin LTXs, and did notice a slight difference in acceleration, especially off the line. Even though the tire height will increase by only .55 inches, you will feel some slowdown.

Going from 255 to 265 (assuming 70 Series), below are the conversion numbers ...

255 Tire = 30.06 inches Diameter
265 Tire = 30.61 inches Diameter

65 MPH will actually be 66.19 MPH (1.19 MPH off)


Below is the converter I used:
B&C Offroad Converter

 

I am all for getting more meat on the road, but 11% is too much. There are option in between. List you exact current size and I'm sure we can find something a little bigger for you. Something like what gpaje did is reasonable.

 

Im currently running 255,70 16 bf land terrains i got 55,000 out of them so im thinking bf all terrains but if jumping up a size is gonna change the feel im not gonna do it and i like my stock rims so i think im stuck at the stock size dont want my accleration to go out the door I was just thinking more meat better ride sounds like i was wrong
love the site

 

An 11% change in the speedo isn't going to happen with that tire swap. I did that exact swap and it was 5-7% off. I didn't get that much variation until I went to 285/75/16s with the original VSS gear still in place. There was a little bit of lag over stock, but it wasn't really that noticable. If you want slow off the line try going to 35s with the stock gears, then you'll feel the true meaning of SLOW.

 

Like Powerstrke said, going to 265/70R16 will be about 5% larger and won't affect performance too much. If you want the extra meat, go for it.

 

Going to the 265/75/16 is basically the same size as the optional 265/70/17 that are/were available from Ford. You should get the speedo adjusted however. It will effect the tranny shifting points noticably.

Besides, they DO look and ride much better IMO!! I had the 235/70/16 on originally and it just looked pathetic!!

 

I have BFG AT/KO size 285/75/16 and there is not much differance between these and the stock tires. Other than these look much better. Performance is much better in that these babies stick to the road, snow, mud whatever. I have no rubbing problems and my speedo is fine when I pass those police radar signs that show how fast you are going. I say go for 285's if you can. I also tow occasionally and have had no problems.