Hey guys,
I just recently installed 285's on my runner and thought i'd ask about the change in my speedometer readings. From what i can tell, theres barely a difference, but i could be wrong. Is it neccessary to have my speedometer re-ajusted after adding these larger tires? Any other important things I should be aware of due to the larger tires?

Any help would be great, thanks.
-Micah

 

Some threads that might help you out...

https://www.yotatech.com/forums/f2/re-gearing-64986/

https://www.yotatech.com/forums/f2/body-lift-questions-64681/

https://www.yotatech.com/forums/f2/oh-yeah-new-tires-just-came-64558/

 

Yeah, here is a nice tire size calculator that will let you know that if you went from a 265/70R16 to a 285/75R16 tire, for example, your Speedometer Difference: would be 7.292% too slow.

http://1010tires.com/TireSizeCalculator.asp

 

Your speedo is going to way off-check it with a GPS. With my 5spd, 4.88's and 285's, mine is 10mph off at highway speeds.

 

Mine is a good 15-20mph off on highway speeds. But atleast if I get pulled I have a semidecent excuse.

 

Alright, thanks for the help guys...I used that calculator and learned that if my speedo showed 60 mph i'll actualy be going ~64mph...I want to get this fixed, so do i just go to my local stealer or to someone else to have my speedo redone?

Thanks again,
Micah

 

well, a better solution that is more popular on here is to regear, which will give back lost power from bigger tires, and will also return the speedometer/odometer to very close to stock reading. but, then comes all the other things with that, such as you HAVE to regear the front also, and then, while you're regearing, might as well put lockers in to save $$ on labor. the price will add up quickly, and if you're not willing to pay all that right now, just have your speedometer changed, i dont know where though....

 

Not necessarily, b/c if that was true then my speedo would be reading fast instead of slow.

28.4" tires and 3.91 gears stock vs. 32.8" tires and 4.88 gears now

 

4.88 gears wtih 32.8" tires? That sounds like the gear ratio is crazy. I did a SAS on my 02, manual, yaddy yaddah, 4.88s with 35s, and i'm back to stock power.

 

That's right, I have more gear than stock. It's the equivalent of having about a 4.23 gear on the factory tires. I tow a 3600 lb camper is why I got them and also in case I want to go to 35's later on.

Got any pics of that SAS? I'm assuming it's a Tacoma?

 

What would you gear if you only planned on running 33's (maybe 34's)? I was planning on a 4.88, but would a 4.56 be more realistic?

 

I think a 4.56 would be correct if you came factory with 4.10's and 31's. Most people on here with auto's go with 4.88's to get a little extra power to turn the bigger tires and the extra weight of the offroad stuff.

 

FWIW I am very happy with my stock 4.30s and 285s. Granted I have a s/c, but there is still plenty of power. If I had 4.10 I would go to at least a 4.56 unless you can find a deal on stock 4.30s and e-locker

 

No, you don't. Try it sometime... :cry: