hello everyone,

i recently had new wheels and tires put on my car.
i did change and go up in tire and in rim size.

my questions are,
would my calibration be off as well as my speedometer?
would i need to have this fixed or adjusted or will it work itself out?
would the dealer or myself be able to adjust this?

looking forward to your replies.
i do appreciate it!

 

the speedometer will be off i believe, you can take it to a shop that specializes in this sort of thing, I am pretty sure they can do it for you pretty easily.

 

what size tires did you have put on? the dealer may be able to recalibrate it, I haven't seen a person recalibrate theirs yet.

 

As long as you maintained a near stock rolling diameter you should be fine without a recalibration.

The stock setup (235/45 - 17) yields an overall diameter of 25.32 inches.
Same or very close to:
235/40 - 18
235/35 - 19
235/30 - 20

 

Yep. As you go up in size, as in diameter, you will register a slower speed than you are actually traveling (also few miles than actually racked up). The reverse is true for smaller diameter tires.

Incidently, the OEM tire diameter for my '04 manual was 25.5 inches - Bridgestone EL42's.

 

there are a few tire websites like www.tirerack.com www.1010tire.com that have a conversion page- enter old tire and rim size and new sizes-
it will tell you what, IF ANY, amount the speedo will read off by

Going up an inch in rim diameter and down in tire profile 2 steps nets a near zero change in the total rolling distance around the tire = the speedo still reads 2mph fast at cruise speed, same as it did on the stock tire setup

 

i had the original sizes,,,,,,now have 235/35/19
thanks for the feedback

 

Should be a wash, as tire OD OE 25.32" to the 19" 25.47" is neglegable, or .4 MPH slower at 60. I noticed that going to 245/45-17's 25.68" brings the speedometer to an almost perfect 60MPH as the reading is slightly fast from the factory.