Hi, new owner here. I was to get a set of BFG mud terrains for my ride. My stock tire is 265/70/16. The closest size BFG makes the mt's in is 265/75/16, which is about 1 inch bigger. Rule of thumb is a 1% change in tire size has no real effect on speedo's and ABS and stuff, but this would be over a 3% change in size. What do people use to recal the speedo for larger tires?

 

I found with my 2001 Tacoma that the change from 265/70R16 to 265/75R16 actually corrected the speedometer. It was more accurate with the 32's than it was with the stock 31's. I have seen that repeated since.

The change will not be a big one, so you might want to make the change before you worry about the speedomter being off.

 

just check it with one of those speed signs once you get the tires, if it was a problem so many people would not run them

 

If your 04 is anything like my 01 there's not much you can do to recalibrate the speedo anyway. I got a Dakota Digital unit when I changed from 225/75R15 to 265/75R16 and couldn't get it to work. The speed sensor sends the signal to so many computers that installing the recalibrator just set off all the warning lights and messed up the ATRAC and VSC. With a 3% change I wouldn't worry about it, and like Rob said it might not have been accurate to start with. Check it with a GPS or milepost markers to be sure.
If it is actually out just keep it in mind when driving. Mine is off by 10% so it's fairly easy to do the math.

 

Cool, thx for the replies. Guess I won't sweat it.

 

I'm going to go to 31's on my '94 4runner 22-re 5 speed. Do I need to recalibrate my speedo gear? If so can anybody tell me where to buy a recalibrated gear? I'm currently running 235/75/15s. Thanks!

 

Get a stopwatch or a GPS and make sure it's off first. Every one I've heard about gets MORE accurate with slightly larger tires...