I have an 08 IS 350 and I just went from 18' summer tires to 17' winter Blizzak wheels from Tire Rack. Does the change in wheel size effect the Speedometer and Mileage? Does this need to be corrected via the dealer?

Also are there alternatives to taking the car to the dealer to input the Tire Sensor codes? My dealer has quoted me as much as an hour and half of work and at least $150 to have them put into the car. It doesn't seem like it should take that long or cost that much.

I am new to the forum and greatly appreciate the assistance.

Best,
Anthony

wheel size: depends on the tire used on the 18" and 17". post up your tire sizes and I will tell you how much difference the speedo is. If done correctly, there should be little to no difference.

tire sensors. If your tire sensors are already programmed for your car, you do not need them to be reprogrammed if you move them to the 17" tire. Once each sensor is programmed, it is in there. However, if you are buying a second set of sensors for the 17" winter tires, try a Toyota dealership....they are usually way cheaper and can do it.

steviej

Thanks for the input Steve, the wheels I used can be found at the link below and I used the Bridgestone Blizzak tires LM25.

http://www.tirerack.com/wheels/WheelCloseU...=Silver+Painted

Will the change in wheel size mess up the mileage as well? I talked to the Lexus Service dept the other day and they said it would not change this as the tire is a little larger on a 17' wheel do the difference is minimal.

Regarding the sensors I need to get them programmed into the car so I will need to take it in. I wish there as some way to do it myself. It seems like it is a really easy task but who knows, right?

Thanks again,
Anthony

Anthony, it is not so much the change in wheel size that messes mileage up as it is the tire mounted on the different size rim.
There are many different size tires that fit on the same 17" rim. you need to list what size Blizzak tire you mounted.

But let's assume the tires for the 17" rims are 225/45-17 in the front and 245/45-17 in the rear
and your tires for the 18" rims are 225/40-18 in the front and 255/40-18 in the rear.

This swap from the 18" tires to the 17" tires would result in a 0.5% difference on the front and 1.3% difference on the rear. Anything less than 2% is acceptable.

Call around to Toyota dealerships, they will program the sensors in for less provided you have the codes. If you are buying them from TireRack, they provide you the codes. Usually they are on the side of the sensor, but once mounted in the tire, you can't see them.

steviej

If your stock 18" size of

another way is to go to Tire Rack.com. Look up the Blizzacks and go to "spec", click on it, and they will have all the sizes the tire comes in, and the outside diameter of all those tires. SO, if your stock 18'' 255-40-18 is say 25'' tall, then just look up the 17'' size that has the same outside diamter, in this case it would be the 225-45-17, but the 235 and 245 would all work just fine.