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Andrew Rolland ![]() Moderator Group ![]() ![]() Go away rain Joined: 19-August-2004 Location: Scotland Status: Offline Points: 6579 |
![]() ![]() ![]() ![]() ![]() Posted: 27-March-2014 at 12:01 |
I know talked about tyres a million times on here but I'm looking at getting a couple of new boots for my E60 to wear at the front.
245/40/R18 93Y currently shod with Dunlop SP Sport 01 Runflats. These type were fitted by BMW when it rolled of the production line nearly 10 years ago.
From a browse on the old t'interweb, I've learnt that tyres now have an energy rating A to G, just like the do when you buy a fridge!
This covers rolling resistance (fuel economy basically), wet braking (the important bit!) and sound.
Now wet braking is improtant to me as is quietness. Fuel isn't, which is why I drive a V8! For every 3dB more the tyre is, it is twice as noisy, so a tyre with a rating of 72dB is twice as noisy as a tyre with a rating of 69dB in theory!
Rolling resistance, the difference between A rating and G rating is 6 litres of fuel per 625 miles or for ease of sums 1 litre per hundred miles.
Wet braking, the difference between A rating and G rating is 18m, approx. 3m per energy rating band.
So I could buy a Dunlop SP Sport 01 Runflats for £159 which has a rolling resistance rating of E, wet braking rating of B and noise level of 69dB.
Or I could buy a Conti Sport Contact 5 for £189 which has a rolling resistance rating of C, wet braking rating of B and a noise level of 72dB. This tyre has the best rolling resistance rating of runflats in this size
Translating all the above and throwing in the price of fuel. I would need to drive over 7,000 miles more with the Conti than the Dunlop to achieve a saving in fuel. In theory I wouldn't stop any better and the car would be noiser. Probably only get 30,000 miles out of the fronts on my car anyway. So another 7k is pie in the sky I would think.
So why should I buy the more expensive Conti?
Proves that these figures are fairly meaningless when you do some sums!
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Be exclusive and drive a Petrol 5 Series!
Current '13 62 F10 535i MSport Auto Previous '04 04 E60 545i SE Auto '03 53 E60 545i SE Auto (Stolen) '98 S E39 523i SE Auto |
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vpricey ![]() Really Senior Member II ![]() ![]() Joined: 07-February-2006 Location: Edinburgh Status: Offline Points: 2252 |
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I'm a bit of a snob when it comes to tyres, and it depends on how it looks when its fitted, the Dunlop SP Sportmax tyres were fitted to my M5 when i first got it, and i didn't really like the way it looked. So knowing the way the M3 looked, it was only one tyre for me, the Michelin PS3. I also noticed that the Dunlops had cracked quite severely, that bad you could see the cord! Having heard some good reviews of the Conti's i think that would be the choice for me, a good looking tyre, well known for good handling and grip too.
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Paul - '87 E30 325i Sport - '99 E39 M5 - '05 E53 X5
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Andrew Rolland ![]() Moderator Group ![]() ![]() Go away rain Joined: 19-August-2004 Location: Scotland Status: Offline Points: 6579 |
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I was waiting for someone to say "they look good" Cambell had made similar comments on a previous thread
![]() I think when all said and done at the end of the day, a recommendation is always good as there is hee haw in it when you look at the tyre label.
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Be exclusive and drive a Petrol 5 Series!
Current '13 62 F10 535i MSport Auto Previous '04 04 E60 545i SE Auto '03 53 E60 545i SE Auto (Stolen) '98 S E39 523i SE Auto |
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Cambell ![]() Really Senior Member II ![]() Joined: 07-January-2007 Status: Offline Points: 3830 |
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Andrew Rolland ![]() Moderator Group ![]() ![]() Go away rain Joined: 19-August-2004 Location: Scotland Status: Offline Points: 6579 |
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The noise rating of a car tyre is based on a sound meter being placed at a certain distance from a car which passes the mic at 50mph WITH THE ENGINE OFF! Make of that what you will! Who drives their car at 50mph with the engine off?
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Be exclusive and drive a Petrol 5 Series!
Current '13 62 F10 535i MSport Auto Previous '04 04 E60 545i SE Auto '03 53 E60 545i SE Auto (Stolen) '98 S E39 523i SE Auto |
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