> Probably. I always had Continental Eco tyres on my Peugeot 306, but the
> spare was Michelin. On the one occasion I had to fit the spare I found
> that the car had lost its sense of balance when cornering, but all was
> well again when the normal road wheel was back in place.

That's not the tyres per se: that's mixing worn tyres of brand X and a
new tyre of brand Y on the same axle.

ian