tyres

I have a Vauxhall Astra 2004 Reg (Mark 4). When I get to around 70 mph the car starts to shake; this is a recent problem. I've had this before (exact same symptoms) and it was due to worn down tyres. However my tyres currently are fine (I've checked tread depth etc). Also I recently torque'd...

I was reading up online about basic tyre maintenance. Has anyone ever heard about "Tyre Rotation" ? I've never heard of it before. It appears to be something you can do to increase the life and safety of your tyres, but it seems like an awful lot of effort. Does anyone actually do it and have...