How many miles do you get out of a set of new tires?

[Boxxy]

New to the 996TT family. My 986 recently got 20-25,000 mi on a set of Kumho Ecsta Supra 712. It's actually at 20,000 now but there's still 15% tread left. No immediate need to change tires.

How will I fare with my 996TT?

My style of driving: daily driver in good weather. 90% commuting to work and city driving. 10% fun/spirited driving. No track/DE or jerk-like driving.

[White987S]

As you know, tire wear is completely modulated by the right foot! What kind of tires on on it now? I would expect you to see similiar mileage, maybe slightly less with the extra HP now. Keep good alignment and tire pressures.

[1999Porsche911]

Tire wear is extremely sensitve to alignment. If your camber is set to the maximum Porsche spec, you can go through a set of rear tires on the street in as little as 7,000 miles. Reduce the camber just 20% and you'll get another 4,000+ out of them. Those who get 20,000 miles out of their rears have their camber and toe set close to the minimum spec.

As with all things in life, you have to compromise. You cannot have both maximum handling ability and maximum tire life. For most drivers, dialing down the alignment is both safe and desirable.

[Boxxy]

Someone in another thread mentioned examining his tires using a pyrometer. In my like of work, I have access to an infra-red gun type pyrometer. Is this good enough? I'm thinking after driving around for a while (what is a while?) and then checking across the face of the tire. I'm thinking I might be able to spot one area of the tire hotter than another, maybe suggesting a change in the camber or toe.

I see when watching races on TV that technicians press something directly on the tire to get its temp. I won't have access to one of those.

I ask about the pyrometer because by the time I would notice abnormal tire wear, a rather significant chunk of the tire would already be lost. [No?]

White: I'm not a show-off (he-heh). So no burnouts with the tires or drifting, etc. Mostly daily driving with occasional fun rides in some nearby mountain twisties. I'm putting on a new set of Kumho Ectsa SPTs after seeing them them workout very well on my 986 and consulting a recent thread here about them for a 996TT (most users were of the same experience as me with them, though one user felt they were not good).

1999: I'm not after 100% grip and so I will look into your advice re: going towards the min camber allowable by Porsche. By min toe, do you mean "as close to zero as possible" [i.e as "straight-ahead as possible"]? Related, what sort of loss in handling could I see with this? My 986 is nimble and handles great; excellent feel of the road. I wouldn't want to end up with a "vague" handling car.

[1999Porsche911]

Someone in another thread mentioned examining his tires using a pyrometer. In my like of work, I have access to an infra-red gun type pyrometer. Is this good enough? I'm thinking after driving around for a while (what is a while?) and then checking across the face of the tire. I'm thinking I might be able to spot one area of the tire hotter than another, maybe suggesting a change in the camber or toe.

I see when watching races on TV that technicians press something directly on the tire to get its temp. I won't have access to one of those.

I ask about the pyrometer because by the time I would notice abnormal tire wear, a rather significant chunk of the tire would already be lost. [No?]

White: I'm not a show-off (he-heh). So no burnouts with the tires or drifting, etc. Mostly daily driving with occasional fun rides in some nearby mountain twisties. I'm putting on a new set of Kumho Ectsa SPTs after seeing them them workout very well on my 986 and consulting a recent thread here about them for a 996TT (most users were of the same experience as me with them, though one user felt they were not good).

1999: I'm not after 100% grip and so I will look into your advice re: going towards the min camber allowable by Porsche. By min toe, do you mean "as close to zero as possible" [i.e as "straight-ahead as possible"]? Related, what sort of loss in handling could I see with this? My 986 is nimble and handles great; excellent feel of the road. I wouldn't want to end up with a "vague" handling car.

You'll notice no less control with aggressive street driving.

[mhall1019]

Someone in another thread mentioned examining his tires using a pyrometer. In my like of work, I have access to an infra-red gun type pyrometer. Is this good enough? I'm thinking after driving around for a while (what is a while?) and then checking across the face of the tire. I'm thinking I might be able to spot one area of the tire hotter than another, maybe suggesting a change in the camber or toe.

I see when watching races on TV that technicians press something directly on the tire to get its temp. I won't have access to one of those.

I ask about the pyrometer because by the time I would notice abnormal tire wear, a rather significant chunk of the tire would already be lost. [No?]

White: I'm not a show-off (he-heh). So no burnouts with the tires or drifting, etc. Mostly daily driving with occasional fun rides in some nearby mountain twisties. I'm putting on a new set of Kumho Ectsa SPTs after seeing them them workout very well on my 986 and consulting a recent thread here about them for a 996TT (most users were of the same experience as me with them, though one user felt they were not good).

1999: I'm not after 100% grip and so I will look into your advice re: going towards the min camber allowable by Porsche. By min toe, do you mean "as close to zero as possible" [i.e as "straight-ahead as possible"]? Related, what sort of loss in handling could I see with this? My 986 is nimble and handles great; excellent feel of the road. I wouldn't want to end up with a "vague" handling car.

Boxxy:

My amateur analysis of the use of tire temperature profiles:

The purpose of the temperature measurement is to determine the temperature profile (and indirectly the amount of friction) across the tire which would give an indication (to an experienced temperature reader) of whether the proper air pressure and suspension settings are being used, and especially to compare readings before and after changes are made to either of those parameters. The IR pyrometer measures surface temperature which will equilibrate very quickly after the car stops, so its not very useful. The proper temperature probe that is inserted into the rubber measures the temperature below the surface before its had time to equilibrate across the tire, a process that starts as soon as heat from friction stops being generated (when it stops rolling). Just like reading your tread depth, if the tire is hotter in the center, the pressure is too high. If the temperature profile across the tire slopes evenly from high at the inside to low at the outside then possibly the camber is too negative. It is not likely you could generate enough tire heat on the street or a curvy road (or an autocross course) to get a meaningful temperature profile across the tires and have time enough to stop the car, jump out and "shoot" all the tires in at least three points across each one and write down the numbers before the temperatures all read the same. This would be especially true with (relatively) hard rubber street tires. And, unless you've got a defective tire with "lumps" on the surface you probably wouldn't see a hot spot that you couldn't detect by the vibrations at that corner of the car.

Also, it just occured to me that they make tires with different compounds and/or tread patterns across the tire to create some traction effects (different friction) that would throw off the whole temperature profile reading thing. I don't know about you but I think I'll stick with the white shoe polish.

[Boxxy]

I see. I guess if the IR gun type worked well, the race guys would be using them... Thanks for the explanation.

I'm still curious then how I can tell if the tires will wear funny if I don't have any equipment.

I think I know how to read feathering (i.e. wrong toe).

Wear caused by incorrect camber would be harder I think. Not until a fair amount of rubber was worn off.

[mhall1019]

I see. I guess if the IR gun type worked well, the race guys would be using them... Thanks for the explanation.

I'm still curious then how I can tell if the tires will wear funny if I don't have any equipment.

I think I know how to read feathering (i.e. wrong toe).

Wear caused by incorrect camber would be harder I think. Not until a fair amount of rubber was worn off.

I think you will have to rely on inspecting and replacing worn suspension parts, having a proper 4-wheel alignment to conservative factory specifications (on a properly calibrated machine) and wheel balancing performed and having them rechecked if you think you might have done something to upset them. The Porsche suspension is well designed and robust and even with the most torturous driving you're likely to put it through on the street (sinkholes and curbs excepted) it maintains the tire contact patch throughout the range of suspension travel. This is what you've paid for. Keeping it aligned and tires balanced and with proper air pressure is about all you have control over that will affect tire wear.

[2wheels4fun]

Now you have me thinking. I have an IR camera, I'll try to jump out and get some pictures to post after spirted driving to see what it looks like.

[Hroussard]

New to the 996TT family. My 986 recently got 20-25,000 mi on a set of Kumho Ecsta Supra 712. It's actually at 20,000 now but there's still 15% tread left. No immediate need to change tires.

How will I fare with my 996TT?

My style of driving: daily driver in good weather. 90% commuting to work and city driving. 10% fun/spirited driving. No track/DE or jerk-like driving.

If you still own your 996... Try this tire:

http://www.tirerack.com/tires/tires.jsp?tireMake=Fuzion&tireModel=ZRi

I got 40K miles in the front and more than 32k on the rear. Note: Tires looks narrow and are slippery for the first few hundred miles... that is the only disadvantage but they work very well in dry weather, little tire noise compared with all the others when 1/2 worn etc. Also had Kumho but this Fuzion is way better and cheaper too..