Tyres, brakes, suspension and oil should be the best you can afford.
Whilst in general your comment is sound, most expensive is not always best.
The difference between a Budget tyre at £30 a Toyo T1R at £45 and a Dunlop SP Sport at £82 is an example.
The Toyo is way ahead of the average £30 ditch finder which justifies the extra £15 a corner, but is the Dunlop worth the extra £37 to get a premium name?
Some even say the Toyo is a better tyre, just less life.
A lot of Midrange tyres can offer good value for money.


