I had new front tyres fitted in January. 255/35/R20 97W at national tyres. 

I now need new rear tyres. Upon shopping around I notice that Halfords believe that my car should have different sized rear tyres to the front - 295/30/R20

No other tyre garage appears to think like this and I must admit, I have never heard of the requirement to vary the tyre sizes front to rear unless the were exceptions such as towing a caravan, of which I have none of. 

Is this actually a thing or are Halfords trying to pull some wool. If they are, why? As the 2 sets of tyres are the same price

1 hour ago, Carl Gibbs said:

I had new front tyres fitted in January. 255/35/R20 97W at national tyres. 

I now need new rear tyres. Upon shopping around I notice that Halfords believe that my car should have different sized rear tyres to the front - 295/30/R20

No other tyre garage appears to think like this and I must admit, I have never heard of the requirement to vary the tyre sizes front to rear unless the were exceptions such as towing a caravan, of which I have none of. 

Is this actually a thing or are Halfords trying to pull some wool. If they are, why? As the 2 sets of tyres are the same price

I feel the advice given by Jaguar in the handbook for the car and/or on a sticker (usually on door pillars) is the correct way to go with tyre sizes.

Best wishes and Regards, John