Hello all,

i bought my TT a week ago and thought i'd change the tyres, i am not really familiar with tyres but i noticed that i have 235/40/R18 in the front and 245/40/R18 in the back, is this normal or should i go for 245/40/R18 all the way?

Thx alot in advance.

 

The prior owner screwed-up bigtime. Quattros MUST have the same circumference front to rear within 1/8"; you've got to get the same size tires all around. If you replace one you'll need to replace all & keep them rotated regularly. If not you'll wear the rear Haldex controller because the different speeds of the tires resulting from different sizes will tell it there's wheel slip occuring and it will be sending power to the rear wheels constantly. The Haldex contains a clutch pack that compensates for differing wheel speeds front to rear; it even has an oil filter to scoop-up clutch bits as they wear. You DON"T want to destroy it; it's very expensive, so get those tires replaced.

 

Which rims? If you can get dimensions of the rim, you can go here and find which size tire will keep you closest to your original rolling radius. Why is that important? If your rolling radius isn't close to what the stock rolling radius is, your speedometer will be off, as well as your odometer consequently.

The calculator is a little more than halfway down the page. Just down from that is a rim size calculator. You don't want to stretch a narrow tire onto a wide rim, or have a wide tire on a narrow rim. Theres a range that works best, and that will help you find it.

 

ok recently thx to you guys, i changed my tyres today from what the previous owner had which was 235/40/18 in front and 245/40/18 in the back to 225/40/18 all around because i have a quttaro, was my choice right? or should i've gone with 245/40/18 or 235/40/18 all around ? cause i checked the optimal size which is 225/45/17 and i thought the 225/40/18 is the right size. plz help

 

225/45-17 up to 225/40-18 is a .46% change according to tyrebible. Good choice.