What are the rules about fitting 2 different tyres to the rear axle of my car?

Question from Peter Burgess, 02/03/2011 :What are the rules about fitting 2 different tyres to the rear axle of my car?
Answer by rezulteo, 02/03/2011 :

English law allows different tyres to be used on the same axle within certain limits:

  • the tyres must be of the same structure (diagonal, radial etc...)
  • they must have the same measurements (tyre dimensions, for example: 195/50x15)
  • they must have compatible load and speed indices

rezulteo's advice: We advise against this practise, mainly because of safety systems like ABS braking use the wheels' speed of rotation to operate.