time666

Hi Guy's
A quick question if I can. Is there any problem with mixing different manufacturer's tyre between the front and rear of the car?

I have Continental Sport Contact 2 N2 rated tyres all around, and I have 1 rear tyre which needs replacing before the pilgrimage to Lemans 24hr next week.

The garage cannot obtain a Conti Sport Contact 2 and Continental are out of them, so I just said ok let swap both rears for another make N rated tyre and they can get me Pirelli Rosso for both rears, but they said they don't recommend different manufacturers tyre between F&R for N-rated tyre, ideally should be the same all around!

I understand the same axle but what do you think for different between F&R? I'm not convinced but thought sensible to ask on the forum.

Ideally I'd like to swap them out on the rear than pay a large fine to the local French local enforcement.

Any advice you could offer is much appreciated.

911Jetta

Here's what TireRack says: (no afil)
(full text here: http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=26)

It is also important to know that while Porsche N-specification tires have been fine tuned to meet the specific performance needs of Porsche vehicles, the tire manufacturers may also build other tires featuring the same name, size and speed rating as the N-specification tires for non-Porsche applications. These tires may not be branded with the Porsche N-specification because they do not share the same internal construction and/or tread compound ingredients as the N-specification tires. Using tires that are not N-specific is not recommended and mixing them with other N-specification tires is not permissible.

Tires should be replaced no less than in pairs on one axle at a time. Only tires of the same tire make and type must be used. However, in case of tire damage such as cuts, punctures, cracks or sidewall bulges that cause a single tire to be replaced for safety reasons, the remaining matching tire on that axle must not exceed 30 percent wear. If the remaining tire has more than 30 percent wear from new, it should also be replaced. Handling inconsistencies may result if this is not done.

Initially, new tires do not offer their full traction. Drivers should therefore drive at moderate speeds during the first 60-100 miles (100-200 km). If new tires are installed on only one axle, a noticeable change in handling occurs due to the different tread depth of the other tires. This happens especially if only rear tires are replaced. However, this condition disappears as new tires are broken in. Drivers should adjust their driving style accordingly.

Note: The last two paragraphs are excerpts from recent Porsche vehicle owner's manuals.


Hope that helps. Enjoy LeMans and take pics for us!

time666

Thanks 911Jetta for the reply, this does help.

I have had to go with the Michelin Pilot Sport 2 which are N3 rated tyre for both the rears, I understand these are an improvement to the previous version of the same but given the short time I have before setting off and that the fronts have loads of tread left, I'm replacing just both rears with new and leave the Continental Sport Contact 2 N2 rated tyres on the front of the car. So it's a mixture of N2 and N3 rated and manufacturers.

It's got to be a better situation than my current border line legal rear contis anyway.
Hopefully this isn't too noticeable or risky.

And yes I'll get some pics of the circus that is Le Mans 24hr, a mate works for a bank so managed to bag pit lane box access at some point during the race, access to Aston Martin hospitality tent and dinner at Hotel de France on the Friday where the Aston team are there, which is where they used to start from in the 70's.
Should be fun rocking up in a pair of Adidas trainers, combat shorts and stinking of bonfire!

C24FUN

I had to replace my rear tires (Yokohama AVS Sports) due to sidewall damage on one from road debris. This model of tire had just been discontinued and since the fronts still had 60% tread left I decided to replace the rears only with Yokohama S-Drives.

I'm not sure if it was the different tread patterns on the two types of tires or some other factor but my handling went from excellent to dangerous after the switch. Even after the new rears were properly worn in I noticed a distinct tendency of eratic turning when driving on the highway. As I turned the wheel to navigate a gradual corner there would be very little response for a second and then the front end would suddenly dart into the turn. This almost caused contact with the center median on a couple of occasions. Since there had been no other changes to the suspension I assumed the cause to be the mismatched tires. I bit the bullet and bought new matching tires for the front and the problem disappeared.

Since then I have been a strong advocate of the "same tires front and back" policy.

Just my 2 cents worth.

Jim G.

time666

Interesting Jim,
Think I'll take your experiences onboard and bit the bullet. I didn't want to replace all 4 corners based that only 1 rear tyre is worn but the cost savings would be rather insignificant when compared to repairing a damaged car!
Thanks for sharing.
Tim

964George

Different levels of treadware can play havoc with a cars handling, hence why its advised to replace both tyres on an axle.
With 4wd vehicles the same applies to all four corners, so its advisable to change all 4 tyres when necessary…

As our cars are 20-25 years old and not covered by warranty, I for one, don’t see the need to use N rated tyres!
Some makes of non N rated tyres can be better than other makes of N rated tyres and the difference between N rated and non N rated of the same tyre would be negligible to most drivers…
You just need to look at the guys who track their street rides to see that there are tyres offering better levels of grip?

I’d rather have 4 new non N rated tyres compared to 2 new N rated and 2 old N rated tyres…
Just my 2 penith (2 cents if you're in the US)

Earlydays

+1

time666

Thanks George,
Yeah I agree mate. I was certainly changing both on the rear axle together.

Was initially going to be 2no continental sport contact 2 (N2) up front existing with good tread, and 2no new Michelin Pilot Sport (N3) at the rear. So tread level would have been even across the axle up front and new on rear.

It was more a question of mixing tyre manufacturers front to rear as opposed to N ratings I was bothered about.

But decided to go with Jims advice and replace all with the Michelin's in the end.

Tyres came with the car when I bought it in 2010 so probably good practice to change them now anyway.

breljohn

I wouldn't. I think you want consistency among your tires