Different diameter tires

[cooper78]

Hi all,

I have a strange one and wondering if anyone has had this problem. I have a MK6 Golf GTI 2011 and recently purchased a 2011 Skoda Octavia RS147. Both are DSG. It is basically the same car so although this is a VW forum I figure the problems will be the same.

Anyway when i use cruise control on the Skoda, it will sometimes change up a couple of gears until I change it back to 6 manually. I also noticed it will sometimes stay in 5th gear but I can change it myself. I dont believe it is the gearbox but I did notice that the car has 225/40/18 on the front and 225/45/18 on the rear. Do you think this could be effecting the computer and making it do crazy things with the changing? I was thinking it could think I am going up a hill and therefore holding the gear.

Depending if the wheels fit, I might put my GTI wheels on the skoda to check!

[ian]

Is it a 4 motion a four wheel drive ,
There is a 3 inch difference in circumference
Tire Size Comparison

Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
225/45-18 4.0in 13.0in 26.0in 81.6in 777 0.0%
225/40-18 3.5in 12.5in 25.1in 78.8in 804 -3.4%

[cooper78]

Hi Ian,

Not that I am aware of!