i went to a smaller tire size and basically my speedometer is off now. instead of traveling 80 mph now i will have to do 83.92 mph to achieve 80 my shiz is off by like 4.67% now. that means my odometer will also be off.

i have spoken with about 10 shops today and numerous lex and toyota folks. the lex dealership service manager just told me on the phone that it is not possible.

i think this is bs and he said nobody has ever needed to or ever even asked about it.

so how do you change the tire size settings in the lex computer???

thanks,

 

A difference close to 5% is a very dangerous level. This alters the input the car gives out to many difference systems not limited to traction and stability control. So its a little more then just incorrect speedo reading.

As far as speed measurement, if memory serves me right, on Lexus cars, the speed is measured at the wheels as opposed to different systems used by other brands (ie driveshaft speed, or transmission). So you might have to alter that sensor.

 

yeah i figured as much with the traction and all the other systems. i guess the quick solution is buying larger rear tires. because it doesn't really seem possible to change the settings or sensors even though i'm confident if i was back in japan a dealer would have helped me out by now...

 

Like I said before, get bigger tires.
235/40/19
255/40/19

 

245/40/19 and 275/35/19

 

i wish i could test fit and test drive a pair of 275 40 19's and then a pair of 275 35 19's on my rear wheels before i purchased them.

 

Find a cheap used tire place and buy some ghetto tires for a 100 bucks....

 

dude no, sorry but i don't think i could bring myself to this. i can buy knock off rims but not knock off tires. tires are like an insurance policy