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Quick Tyre Decision

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Hey Guys,

After some advice

I have the chance to buy a set of Dunlop SP Sport 9000 tyres for the front of my boxster S (225/40 R18) for £115. They are part worn and have 5 - 6mm of tread left, or for slight more (about £150) I could get some cheap brand new tyres, such as, Kumho ECSTA 711, Centurio, Nankang, Linglong, or Falken (all of similar value of around £70 per tyre)

What do you recommend I do??

Many thanks


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I had a set of the Dunlops and they are superb in every area, especially wet weather performance. As far as I am concerned, mixing brands is not recommended by the factory because of liability, but in reality should be fine in most instances. I ran 9000s on the back and P Zeros on the front for about a year with no problems. The F & R are different sizes to begin with, and slightly different tread patterns, compounds, and casing designs shouldn't matter. It's more important to run correct air pressures.

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Hi guys,

At present Im running Dunlop Sp Sport 9090 on the rears, and Michelin Piolt Sport on the front.

Its the fronts that have worn - 225/40/R18

I guess the dunlops would be the better choice to match the rears, but is it not better get brand new tyres of the cheaper brands I wrote.

Will 5-6mm tread on the part worn dunlops last for quite a while??

Many thanks


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I had been running Michelin Pilots for years and paying thousands of $ each year for tires (996 - with 285 - 30 -18 rears twice per year)

I recently started using the KUMHO 295-30-18 (and in front the 235-40-18) and am VERY VERY pleased. They cost about a 1/3 as much, handle very well in the dry, have superb wet traction and seem to wear much less. I will never go back. They are smooth, quiet and the balance is excellent. My 996 has the PSS9 suspension set to about 50% firm F/R and after a 19 hour drive from KC to Montreal (F1 weekend) both I and my co-driver were totally refreshed. After 7 identical drives using the Michelins this was by far the best thanks to the tires.

A set of 4 given my sizes is less then $600 including road hazard protection. What a deal, if you drive your car a lot, which you should. Again, I can't stress how well these also do in the rain. Flat out in first gear - the car just goes where you point it in the RAIN - awesome. I would like to hear from others who have tried these tires.

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You wouldnt catch me putting used tyres on.

They could have been down pot holes, over kerbs etc and who is to know if the sidewall is weakened?

The only time tou may find out is a high speed blow out that could be the the end of your life...

Driving a Porsche and trying to save a few £s on tyres???

Dont do it. Its just not worth it. They are the only thing that keeps you on the road.

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Phil, I have to say mate, fair play to your reply, you have summed it up exactly to the point.

So I think, even though I have got Dunlops on the rear and its not idea to mix and match, I think Im going to go for a brand new set of Kumho 711 (225/40 ZR18 88W BSW) tyres rather than the part work dunlop sp sport 9000

many thanks for your help all


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You are aware of the danger of mixing tires which give different traction on the front and rear?

You wouldn't be allowed to do this in Germany, for example. I once had to replace 2 tires on a rental there just so the tire depth would match after one blew out.

The general rule is to try to keep the same design and tread depth on all 4 wheels as that is what the anti-lock brakes are designed for and how the suspension works best.

Normal driving, it probably isn't a problem. But put in some weather and a suddent emergency and tires are the last thing I want to have saved $ on. I depend on that contact patch to save my ... from my dumb mistakes and the mistakes of others not to mention nature and the highway crews doings.

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OTOH, I'm running on a set of used tires, that were on a set of wheels I bought. They were take offs sold by a dealer who took them in trade and so I knew the reason they were available. Didn't need mounting, balancing, etc. Been flawless for 8k miles.

The difference between my used tire purchase and yours is I had all 4 matching in design and tread depth as well as knowing the reason for the availability. You don't have those going for you in the 2 options you propose.

Drive safely, the $ you save may cost you your life (or someone elses).

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Hi Guys,

Ok Ok Ok, I get the hint, but obviously mix and match tyres are not a good idea, but they are not life threatening. Automotive design engineers (which I am degree qualified in) design the geometric properties of vehicles suspension to be safe under a whole load of legislation criteria, the simple fact of having different tread depths and tyre manufactures on a vehicle will not drop the handling safety of a vehicle to a point of being highly dangerous, do you know of any vehicles that are on the road this second, including sports cars and super cars that have perfectly matched depths, I think not. Providing tyres are designed to a good coefficient of friction, then no matter what; they will adhere to the road surface. Even under wet conditions, although some tyres are bad and others are good in these conditions, they are all designed with the same target in mind, to prevent a layer of water separating the tyre from the road.

I can understand these points for race track cars where tyres loads are heavily increased.

I have just brought property abroad so hence the saving of money, and I simply asked between the two choices I stated what would be the best.

I have been running on Dunlop’s on the rear and Michelins on the front for 8 months now, and its the best handling Boxster I have had so far, out of 5, even with the fronts being extremely low on tread, it still handles outstandingly.

If any one can offer they suggestions on the initial choices I would appreciate it, but I’m guessing most of you will lean towards buying new tyres and not part worn so I think I will get the Kuhmos.

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