Tire issue

[Navigueur]

Need advice...

New owner of a 1989 911 Carrera Cabrio. Current set-up is Dunlop SP 9000
205/55VR16 225/50VR16
6.0Jx16 8.0Jx16

Front tires have cracks at bottom of thread from old age; rears are newer and more than 60% left on them.

Would want to replace fronts; No longer made in this size by Dunlop!!!

They suggest a Direzza DZ101, a newer model made in this size.

Should I mix tire models of same Brand, on a 911? I hate to throw away a good set of rear tires!!!

My use is boulevard and freeway use, no track ever...



I have similar problems on another car, with Exclaim UHPs from General... and with a motorhome Goodyear tires with cracks on sidewall... Can't they make tires that last more than 4 years? But that is another story...

[Noah930]

The purists will cry out no. What happens when you come around a curve and the fronts grip but the rears don't? What if it's during an emergency maneuver? That tail-happy nature of the 911 will really bite you, then.

At the same time, I've done it before (mixing different tires front and rear). No problems. Admittedly, though, I had the grippier tires on the rear so the car would tend to push (understeer). Still, I think if you're a moderate/casual street driver and aren't carving canyons it's not as big a deal as some would make it out to be.

[petevb]

Originally Posted by Navigueur

Need advice...

New owner of a 1989 911 Carrera Cabrio. Current set-up is Dunlop SP 9000
205/55VR16 225/50VR16
6.0Jx16 8.0Jx16

Front tires have cracks at bottom of thread from old age; rears are newer and more than 60% left on them.

Would want to replace fronts; No longer made in this size by Dunlop!!!

They suggest a Direzza DZ101, a newer model made in this size.

Should I mix tire models of same Brand, on a 911? I hate to throw away a good set of rear tires!!!

My use is boulevard and freeway use, no track ever...



I have similar problems on another car, with Exclaim UHPs from General... and with a motorhome Goodyear tires with cracks on sidewall... Can't they make tires that last more than 4 years? But that is another story...

How old are the rear SP9000s? Do you drive in the rain? Snow?

[IROC]

Originally Posted by Navigueur

Should I mix tire models of same Brand, on a 911? I hate to throw away a good set of rear tires!!!

Don't worry about it. I've done it (even on the track years ago) and it was a complete non-issue. If you're driving at the absolute limit of adhesion all the time, you might actually be able to tell the difference. If you're not, you'll probably never know they're not the same...

[Jesse16]

I agree, I think the "matched set" argument is overkill for low performance driving. I actually have an unmatched set and have been doing DE's. Not an issue either until I'm a better driver than the car. Hell, the tires are doing different things front to back and they're already different sizes. I'll match em up at least once while I own the car.

[wayner]

I care less about the same manufacturer and more about traction ratings. DO NOT put a racing slick on the front with a snow tire on the back for summer driving :-)

[tharbert]

You mention "They" suggested... Who are they? It might be worth a call to Dunlop:

Dunlop Customer Assistance Center:
Please call 1-800-321-2136 M-F 8:30AM - 5:00PM EST for additional assistance.


VINTAGE TIRE INFORMATION:
For information about Dunlop brand vintage tires, please call Vintage Tyres Limited, Dunlop’s North America classic tire distributor. US:717-534-0715 CAN:902-228-2335

[gregwils]

Before you consider tread patterns and traction, you should consider the age of the tires. You don't need to be on the track for a tire to fail from old age. There have been a few recent articles stating the maximum safe age for any tire is five years. Some things I have read say six years, but anything older starts to become a real safety risk. You can look at the DOT stamp on the tire to determine the date of manufacture.

Tire Tech Information - Determining the Age of a Tire

[Navigueur]

Really appreciate all the comments on this situation.

I have yet to check age of rear tires; I think they were replaced a couple of years ago, and are good for a while yet...

I will be putting Dunlop Direzza DZ101 on front, which are said to be comparable in specs...

I am not racing, nor using car at extreme of its capabilities; should be OK...


BUT

Now I learn that some manufacturers, including Porsche, are introducing ''N'' designations for tires specified for their cars; installing others could cancel the warranty...

If true, that is going too far; tire manufacturers do not guaranty availability of the tire model for the life of the car, yet are pleased to be exclusive provider of original and replacement tires...

That is a one-sided monopoly... Sucks...

[Navigueur]

Originally Posted by tharbert

You mention "They" suggested... Who are they? It might be worth a call to Dunlop:

Dunlop Customer Assistance Center:
Please call 1-800-321-2136 M-F 8:30AM - 5:00PM EST for additional assistance.


VINTAGE TIRE INFORMATION:
For information about Dunlop brand vintage tires, please call Vintage Tyres Limited, Dunlop’s North America classic tire distributor. US:717-534-0715 CAN:902-228-2335

I sent Dunlop an Email about this and did not get a response...

Thanks... I will try phone...

By the way, car is only used in summer, and rain avoided when possible...

[nesslar]

Even though your rear tires were replaced "only a couple of years ago", it doesn't guarantee that they were "new" at the time. Case in point, my Son's BMW had "new tires" put on only a few years ago (car has complete records), but those tires are dated week 39, 2003!! I don't recall offhand who did the swap for the PO, but they will be replaced, even though having good tread. I'd suggest please check the mfr. dates....

[Noah930]

Originally Posted by Navigueur

BUT

Now I learn that some manufacturers, including Porsche, are introducing ''N'' designations for tires specified for their cars; installing others could cancel the warranty...

Yeah, I'm not too worried about that in my '87.

It's like that auto parts store commercial says: After 3 years and 36K miles, I'm the warranty.