[David Hodgson]

Cameron

It appears I was telling porky's about the 255/60 710 potenzas being V rated. I had a look at mine last night and they are H rated. Best check with the Bridgestone guy before ordering.

Sorry if I've given you a bum steer.

These speed ratings are for maximum sustained speeds (not if surpassed briefly) at the max load rating i.e. H rating is max "sustained" speed of 210kph at 710 kg per tyre for a 225/60 and about 750 kg per tyre for a 255/60. So thats a total allowable wieght of 2,920 kg. Your DRB would wiegh about 1150 kg? and you wouldn't be sustaining 210kph very often let alone 230kph for a V rated tyre.

As I said previously, your engineer should also do a theorietical top speed calc. This is done by using installed gearing ratio's, tyre circumfrence and the most critical is the rpm at which either the max HP or Torque is produced (can't remember which). Try and convince them its a stock 5.0 efi, about 175kw.

Also ask them where is it that you can drive at these speeds.

Don't let them pull the wool over your eyes, ask them why they want V rated tyres.

Dave