Computer reprogrammed for tire size? - Toyota Tundra Forums : Tundra Solutions Forum

maddogsvolusia · #1 (**permalink**) 05-09-2006, 01:53 PM

I just put 265/70/17s Revos on my Sequoia, and since they are about an inch larger in Diameter than the Dunlops, my odometer and speedometer are obviously off. I'm about 4 mph slow on the speedometer than actual and about 1/2 mile per 10 miles off actual on the odometer. Can the computer be reprogrammed for tire size using a code reader? I would think the wheel speed sensors are just sending pulses to the main unit, so the unit should be able to be programmed to interpret pulses based on tire size. Just curious. It would be a good way to get another tool in under the radar.

Johnnny Rock · #2 (**permalink**) 05-09-2006, 02:05 PM

Quote:

Originally Posted by maddogsvolusia

I just put 265/70/17s Revos on my Sequoia, and since they are about an inch larger in Diameter than the Dunlops, my odometer and speedometer are obviously off. I'm about 4 mph slow on the speedometer than actual and about 1/2 mile per 10 miles off actual on the odometer. Can the computer be reprogrammed for tire size using a code reader? I would think the wheel speed sensors are just sending pulses to the main unit, so the unit should be able to be programmed to interpret pulses based on tire size. Just curious. It would be a good way to get another tool in under the radar.

I put the same tires on as you but I would rather leave it the way it is because my WARRANTY will LAST LONGER!!!! Johnnny

-=tg=- · #3 (**permalink**) 05-12-2006, 01:42 PM

Has anyone noticed that on most cars for decades that speedometers over report actual speed and odometers are just a little fast?

Just think of the benefit to industry in cutting 5%-10% off of all warantees and government looking the other way as people are actually driving slower than they think they are. Hmm...

mustang67408 · #4 (**permalink**) 05-12-2006, 06:06 PM

Quote:

Originally Posted by maddogsvolusia

I just put 265/70/17s Revos on my Sequoia, and since they are about an inch larger in Diameter than the Dunlops, my odometer and speedometer are obviously off. I'm about 4 mph slow on the speedometer than actual and about 1/2 mile per 10 miles off actual on the odometer. Can the computer be reprogrammed for tire size using a code reader? I would think the wheel speed sensors are just sending pulses to the main unit, so the unit should be able to be programmed to interpret pulses based on tire size. Just curious. It would be a good way to get another tool in under the radar.

No the computer can not be reprogrammed. you can buy a product called
TRUSPEED Speedo Recalibrator. It can be wired into the signal going to the speedeometer head and will change the readings.
Do a search, it has been discused many times and will work on your 2003 Sequoia.

dfunk · #5 (**permalink**) 05-12-2006, 07:31 PM

I did 285/75/R17s , the car does have a little less torque so the gearings a bit off, but the speed is not that inaccurate. Or those little radar machines on speed limit signs and police cars are off. Maybe a mile or two off @ 80mph but if its over reported as it seems to be then you should be fine.

maddogsvolusia · #6 (**permalink**) 05-12-2006, 11:13 PM

I was using a hand held Garmin GPS unit to get the numbers I posted. I don't know how accurate they actually are, but they advertise within 3 ft I believe. It's definitely not the end of the world, and the warrantee will last longer; it just amazes me that with all this technology, the computer cannot be adjusted for different pulse signatures based on tire size.