Speedometer Error With Tire Change

Hi Folks, newbie here.

I recently bought a 2002 PreRunner which came with 31" BFG 265/75R/16 tires. Not the tires I wanted so replaced them with 265/70R/16, which is the size my truck originally came with.

LOT smoother ride, but now the speedometer is off. On the highway today, 70 mph on the speedometer was about 66 mph on the GPS.

The speedometer was just about right on as compared to the GPS with the taller tires.

So, what procedure do I use to recalibrate the speedo to match up with the new (original size) tires?

Any help would be appreciated!

Thanks

 

Well see there is a thing with the GPS. its usually a tad bit slower for some reason. Something to do with the satelites and such. With the other tires you may have thought it was right, but in reality it was off.

 

the speedo on the tacoma is computerized. you'll need an electronic speed calibrator to re set your speedo. a few switches, and it's good to go.

http://www.4x4wire.com/toyota/tech/tacoma_speedometer/

this will help.

 

Thanks to all for the replies.

That'll give me something to chew on

I am making the assumption that the speedo was correct with the original factory tires, so the previous owner somehow recalibrated the speedo when he put the larger tires on, since they were larger than the originals, and the speedo was correct with the larger tires.

Anyway, the link may provide the info I need.

About 25 years ago I had a Dodge van with a mis-calibrated speedometer. Turned out that someone had replaced the transmission with one from a car, and so the speedo gear was sending the wrong info to the speedometer. I stopped by a tranny shop and picked up another one and it was a simple replacement on the side of the tranny and all was well. This new "tronic" stuff should be simpler, but sometimes seems more involved.

Regards.