Tyre question

My Volvo 340GL was supplied new with Dunlop 175/70R13 tyres, and every replacement since has been with Dunlop tyres. However the T-rated tyres are not exactly correct for the 340 and should have been on the 360, which is slightly quicker and around 242lb heavier; the 340 should really have SR rated tyres.

Although T-rated tyres were just about tolerable in the past, our roads are now much worse. Early 340 tyres were set to 24psi on the front and 29psi on the rear, now the settings are 27psi front and 30psi rear. In an attempt to improve the ride, I have had new road springs, dampers and bushes fitted; the bushes fitted were polybushes because that is all that is now available.

What tyre would you recommend in a 175/70 SR13 or 155/80 SR13 to replace my tyres (all on 5J rims) to soften the ride? Wide rain channels are out because they will trap a lot of air and noise. Richard Dodd The speed rating of the T-rated tyre is 118mph and the S-rated tyre is 113mph, so there is really very little difference – the R in the rating only indicates that the tyre is a radial. The standard practice is to always replace a tyre with the same or a higher speed-rated tyre.

As your vehicle is fitted with 175/70 tyres, fitting the 155/80 ratio tyres would alter the outer circumference of the tyre, affecting the speedometer reading slightly. I do not believe this would make a great difference to the quality of the ride.

It is possible that switching to a tyre such as a Yokohama, which is of a slightly different construction to the Dunlop, may give you a slight improvement in the ride. I would also keep the tyre pressures to the earlier lower pressure settings.