Tyre options for 928 S4?

[Markw928]

I am relatively new to the performance car game but I am the happy owner of a 928 S4. I enjoy the car's performance but I am not taking it to its limits. I would appreciate some advice about tyre options.

The car is generally in remarkably original condition. This was one of the reasons I went for it and I would like to keep the car's originality for several reasons. Someone has suggested fitting larger wheels to increase the tyre choice but this not something I would like to consider.

It is currently fitted with 5 year old Continental ContiSportContacts all round. The rears have about 3.5-4.0mm tread left and the fronts 6-7mm. Overall the tyres look in reasonable condition. The wheels are original 16in flat disc (?) design, 7J front and 8J rear.

1. While some way off the legal minimum I wonder when people would recommend replacing tyres, especially the rears which carry the power. It does not seem wise to push them to the 1.6mm limit! I am happy to replace them when appropriate but there seems no point in wasting rubber.

2. ContiSportContacts are no longer available and the choice of 245/45 R16 tyres is very limited. For most options no front 225/50 R16s are available. The only options to fit identical tyres on both axles seem to be Pirellis - P-Zeros or Cinturato P7s. However, what are the pros and cons of mixing tyre types front and rear? Is mixing advisable/safe?

3. Cheaper W+ rated tyres available. Are these a viable/sensible option? Cost has to be one consideration especially if it seems advisable to replace all four tyres simultaneously...£££££! I have experienced the potential costs of Porsche ownership but I need to balance choice and necessity.

4. Finally, is formal Porsche N rating necessary given that this was not applicable when my 1987 928 was built?

Many thanks in advance for any comments and advice.

Mark

 

[SmiffyPR]

Tyre age. Some people put limits on age, but tyre deterioration will depend a lot on temperature and UV exposure. Best bet is to look for cracks, usually in the tread grooves. If they are cracking, replace, if they're not they should be okay.

Last 16" ones I bought were Continentals, but at the time Yokohamas were also available as well as Bridgestones and Pirellis at the higher price end.

Mixing tyres front and rear will be okay most of the time, but differences will show up just at the time you don't need them to. I would stick with matched tyres unless you are on a really tight budget.

W rated tyres will be fine. I think the MoT will expect tyres to be rated for the top speed of the vehicle.

N rated tyres will have their carcass stiffness matched to Porsche's suspension, but you might well prefer more grip to more "perfect" balance. If you don't push the limits of the handling, don't worry about it.

Smiffy

 

[Dougal Cawley]

Pirelli do now make the original P7 Cinturato tyres for these cars, at Porsches request. Porsche have tested these tyres and homologated them with the N.

Worth noting that tyre technology has moved on to compliment the chassis design of the current cars. so these period Pirelli P7 tyres will handle better on your cars. A modern tyre wiull handle better on a mnodern tyre, a classic tyre will handle better on a tyre that it is designed to run with.