alloy

Hi, I bought a used troc tdi 2019 from a main dealer three weeks ago - 19 inch alloys. On the long motorway drive home, tyre pressure light came on. Checked and it was 12 psi and reinflated. Took the car to a tyre shop, no leak found. Resealed and new valve. Couple of days later, again tyre...

Hey everone, Can someone help me get my head around the general rules in changing wheels/tyres on a car? I've got an old mk4 astra, and the tyres are going to want replacing soon. Seeing alloy wheels with tyres pop up second hand is quite tempting especially when they're about the same price...