[PaulD]

Hi Ian. I read a few articles about this last winter. The consensus and my conclusion is that rotation of tyres is an American fashion where, I believe, tyres often last longer than the UK, partly as a result of a guaranteed minimum mileage. Others may know more about this than I do. Tyre rotation used to be prevalent in the UK until about 25 years ago but now seen as not necessary. However, the consensus was that new tyres should be replaced preferably in pairs on the same axle (as you do already) and placed on the main driving axel. I consider this to be the rear axle even for 4WD cars. The partly worn tyres should be moved to the secondary axle (front).

 

[PaulD]

Thanks for the replies. I don't really fancy the idea of having to replace all 4 in one go and, barring any punctures, that would mean replacing 2 at a time on the same axle. I had an issue with my Ampera when new tyres were put on the rear and then on certain corners (not even winging it round the corner) the traction control light would come on and the stability control would kick in. After a bit of discussion in the Ampera pages, it seems that there was enough differential between new and worn tyres to make the car think that grip had been lost on one of the axles. The Ampera was only FWD and I am more concerned with this sort of reaction to two new tyres on one axle and two worn on the other.
I will get the depth checked and see how they are wearing.
@PaulD
I remember seeing in a handbook, possibly my first car how the tyres were meant to be rotated using the spare-
Spare to the front offside, front offside to the rear nearside, rear nearside to the read offside, rear offside to the front nearside and the front nearside into the boot. Maybe it was a carryover from the days of old cross-ply tyres.
The American tyre wear being better could well be because they don't have as many windy roads and the long straight freeways.

Yes, I recall those days too. A factor that applies now that is fairly new is that often tyres are rotation direction dependant. That is, a tyre could no longer be switched from nearside to offside on the same axle because it would then rotate in the wrong way.