for someone puchasing 18" stock SS rims to put on their LT which have 17" rims now, can the dealer make the change through the Tech ll for speedo correction? And I would imagine that is the only change neccessary....
thanks for any info.............................................. Tom

 

Seems with the right sized tire you wouldn't even need to do that...... if overall diameter stays the same the speedo wouldn't know the difference.


Someone correct me if I'm wrong......

 

Just google Wheel Plus Sizing. Your tires will keep the same overall height, just have a larger wheel in the middle. Naturally, you tires will have a lower profile but your speedo will never know what happened.

Or, chances are...if you are getting HHR SS wheels, the tires may already be very close to the profile you need anyway!!

Here is a link to a plus sizing calculator to help you out.

tiresizecalculator

 

Yup, they can do it, I had them calibrate mine when I went from 16" - 18" wheels
There was a diameter difference between my wheels.

 

I checked this out when I bought my 18's for my HHR, and if I remember right it only made the speedo like 1/2 a mph off. I wasnt worried about that teeny tiny lil bit.

 

I went from the factory 215/55/R16 steel wheels to a set of cobalt SS/SC wheels wrapped in 235/45/r18's and my speedo is only off by .2 MPH's at 60...

 

thanking everyone for the replies, much appreciated.

a person interested in the SS wheels I have for sale, would be replacing the 17" wheels on his LT, if he decides to purchase and was concerned about the recal of the speedo, this answers his concerns..............