Im thinking of getting some 33's for my 95 4runner pretty soon and i was wondering if my speedometer would be off.

 

yeah itll be pretty minimal especially if you had 31's though. The faster you go the more it will be off. I think at like 70 mph its still only like 4 mph off. Do a search for gear calculators and youll find what u want.

 

http://www.tyres1.com/calculators.html

enjoy

 

At 65 mph I am actually going closer to 75 mph with 285/75/16, as I clocked it with a friend going to work last week. I would say you are going to be anywhere from 1.1 to 1.2 times off depending on how fast you are going with 33s. Getting your speedo redone I think cost in excess of $100 at the stealer.

 

Yup, it's all a ratio of your new diameter to your old. FWIW, my speedo is off by 30%. 49mph on the speedo is 70mph true.

 

Have a friend pace you, or use the speedo function on a GPS. I made a corection chart for my kids truck so he would know how fast he was going. (still got a ticket for 91)

 

Hey Brian I dont c how you could be ten mph off when just going up to a 285. Im not trash talkin ya...It just doesn't make sense to me how you could be that far off. Like the calculator shows if you went from a 31 to 33 (close to 285) you couldn't be more than 5 mpg off or so.

 

Ah, but here is the reason. I went from 225s to 285s, NOT 265s to 285s, so my tires in essence went from 28 OD to 33 OD, thus the bigger difference. I shoulda mentioned that earlier. My bad! :pat:

 

I was gonna mention that you must have started with a smaller tire size.

 

Something else to bring up is the odometer... I moved from 255/75/R16's to 265/75/R16's and found that my speedometer is now _dead on_, while my odometer reads 3% low.

That 3% is the same 3% that comes from the change in tire size. And yes, my spedo used to read slow (as checked with a GPS).

 

is taking your truck to the dealer the only way to fix the inaccturate speedometer?

mine stayed dead on with the 32s, but now with the 33s it's off. when it says 70, i'm really going about 73.5. i'd not a high priority, but i would like to get it fixed.

 

No. It depends if you have a gear driven speedometer or an electronic one. I forget the year they were changed over. Mine is a gear driven, so what I did was get a little gear adapter that attaches to the transmission. I got it from Tacoma Speedometer.

Tacoma Speedometer & Instrument
10526 Steele St S Ste A
Lakewood, WA 98499

(253) 582-3890

(800) 6-SPEEDO

http://www.tacomaspeedometer.com/

It takes about 2 minutes to install and comes with a one year warranty.