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PostPosted: Fri Dec 08, 2006 3:56 pm
by nuster100
Most modded car owners swear by toyo.

I think they do some of the lowest profile stuff you can get your hands on.

Jay

PostPosted: Fri Dec 08, 2006 4:30 pm
by ScoobyChris
nuster100 wrote:Most modded car owners swear by toyo.


Most I know used to swear by them after Bridgestone dropped the SO2-PP. That was a couple of years back though and then the Goodyear Eagle F1's came along, and current favourite seems to be the Pirelli PZero Nero's. Although, I guess it all depends what you want from a tyre and also the size you need! :)

Chris

PostPosted: Sun Dec 10, 2006 2:14 pm
by stefan einz
I agree with the statement made earlier that you tend to get what you pay for.

Personally, and without any implied criticism of others who take a different route, I have always wanted to fit the best possible tyres to my cars given how vital their performance is to grip and safety.

I would strongly recommend retaining the manufacturer's approved brands on a car because those tyres will have been tested to hell and back before being approved. (I have spent many hours talking to Dirk Schoysman, the 'Ringmeister, who tests tyres for a living.)

For example, Porsche develop in conjuction with tyre manufacturers specific compounds for specific tyre makes (eg, MPS2s, Pirelli Corsa) for their cars, and these tyres are then given an "N" rating.

I would agree with the guidance which says it is preferable to run a single brand / type of tyre on all four wheels. At the same time, it is imperative to avoid mixing tyres across the same "axle".

Earlier there was a comment about not replacing Michelin PAX (ie, run flat tyres) with normal tyres. I would agree with the statment if that involved switching out just one tyre across an "axle". However, there is nothing I am aware of which would prevent an owner throwing away all the PAX tyres and replacing them with normal tyres. Personally, I have a lot of experience with BMW OEM fit run flats, and I think they are awful. They increase unsprung weight with all the attendant problems that brings. As a comparison, I ran a 535d with OEM run flats. I now run another 5 series (with bigger 19 inch wheels) with lower profile standard Michelin Pilot Sport2 tyres and the improvement in ride is very significant.

I suspect the issue with tyre failure when not running PAX tyres is that people just don't notice a slow puncture, or indeed check their tyre pressures often enough. A run flat tyre will take this abuse far better because of its strengthened sidewalls and is less likely therefore to blowout when under inflated.

Kind regards

Steve

PostPosted: Sun Dec 10, 2006 8:17 pm
by Nigel
I have a little point on the "sticking to what the manufactourers fit" statement.

I'm advised you will not be able to buy the same tyres, I'm told they are of a different compound, just like a replacement windscreen or exhaust will never be the same as the factory fit.

I'm told this by my mates in the trade, I don't have any proof.

PostPosted: Sun Dec 10, 2006 8:40 pm
by ScoobyChris
I always assumed that the tyres that went on the car were whatever was available to the manufacturers at the time (hence why the same model could appear with Michelin's or Bridgestone's). I have no problem switching to a brand I like, but will often seek out recommendations from current owners to see what the genearl consensus for recommendations for the car are :D

Chris

PostPosted: Sun Dec 10, 2006 8:56 pm
by stefan einz
Depending on the vehicle, the manufacturer may approve several tyres for use. As you say, which set is fitted on delivery may depend on the then supply agreements with the tyre manufacturers.

On compounds, I think it is correct to say that all tyre manufacturers continue to develop their tyres year on year. However, if you contact the car manufacturer they will always be able to tell you which tyres are currently approved. There is far too large a liability risk for car and tyre manufacturers to take a risk in this regard - they will always be able to give you current and correct advice.

Increasingly, tyres for certain high performance cars are designed specifically for that car. For example, the Michelin Pilot Sport Cups for the M3 CSL. More recently, Michelin have designed a modified Cup tyre for the GT3. Michelin also designed a very special Pilot Sport 2 for the Carrera GT (with dual compounds). Pirellii have developed several bespoke tyres for Ferraris. Tyre manufacturers will always keep such tyres available.

Kind regards

Steve

PostPosted: Mon Dec 11, 2006 9:21 am
by jont
Well, just for the record I've gone with Goodyear Eagle F1s. Only done about 20 or so miles over the weekend, but have already noticed the improvement in the wet (the old tyres were on about 3mm, but were a horrible no-name make).

Jon

PostPosted: Fri Dec 22, 2006 12:41 am
by AdamW

PostPosted: Wed Jan 17, 2007 2:09 am
by SammyTheSnake
stefan einz wrote:Michelin also designed a very special Pilot Sport 2 for the Carrera GT (with dual compounds).


What's the advantage gained by dual compound tyres on a car? On a bike, you lean into corners and use a different part of the tyre, which is often more grippy (and not so hard wearing) when you most need the grip, but I don't see how this works on a car unless the side-walls are very flexible :shock:

I assume, as always, that I'm missing something crucial :P

Cheers & God bless
Sam "SammyTheSnake" Penny

PostPosted: Wed Jan 17, 2007 11:50 am
by stefan einz
What's the advantage gained by dual compound tyres on a car? On a bike, you lean into corners and use a different part of the tyre, which is often more grippy (and not so hard wearing) when you most need the grip, but I don't see how this works on a car unless the side-walls are very flexible


The best thing I can do is quote Walter Rohrl as follows:

“The parameters we set for the tyres were very critical, so we decided just to work with just one supplier, in this case Michelin. They supplied over 10 prototype tyres before we were happy, but they are absolutely brilliant now. These are quite unique tyres as they have a harder compound on the outer third of the read and wear evenly across the tread, which shows the suspension set up is perfect and even have a good wear rate so you will probably get 10,000km out of a set in normal driving. They even lasted 2,000km in testing at the Nurburgring!”

I think the idea is simply this - under hard cornering, with a generally road biaised set up (ie, not too much camber), the outer edges of the tyre will take a more significant load. The tyres are harder on the outer edge to then facilitate even wear under these conditions.

Kind regards

Steve

PostPosted: Wed Jan 17, 2007 8:40 pm
by Malky
I would not worry about the difference with 3mm -v- 4mm. With new EU regulations on the way, it will be a minimum of 3mm shortly.

Regards

Malky

PostPosted: Tue Jan 08, 2008 6:58 pm
by Darren
ScoobyChris wrote:Recent tests by MIRA Ltd (formerly the Motor Industry Research Association) found that cars travelling at 50mph in wet conditions and running on tyres with the legal minimum 1.6mm tread depth took almost an entire bus length (8 metres) longer to stop at 50mph than those with a 3mm tread depth. With 75,000 road accidents attributed to bad weather conditions each year, changing tyres when the tread depth has worn down to 3mm, instead of 1.6mm, could be the difference between life and death. This is a view shared by several car manufacturers who suggest that tyre performance and safety margins decrease significantly once tread depth reaches 3mm, owing to a reduction in grip and an increased rise of aquaplaning.Chris


Chris, do you have a reference for this? I am in dispute over the supplier of my company car who won't pay to change the tyres because they are still above the legal minimum.....

PostPosted: Tue Jan 08, 2008 8:12 pm
by ScoobyChris
A post from a while back, but I think I got it from http://www.rospa.com/roadsafety/advice/ ... _depth.htm

Interestingly, I had been running around on tyres with less than 3mm tread depth and can't say I noticed any difference in wet weather handling or stopping distances, so the cynic in me wonders if it's just a marketing ploy to shift more tyres.

Chris

PostPosted: Tue Jan 08, 2008 8:13 pm
by 7db
I don't, and I'm due a change shortly. I can definitely notice the fall off in the wet, but I've got a skitty steed when it's damp.

PostPosted: Tue Jan 08, 2008 8:20 pm
by Darren
Dammit, I should check the very material I post sometime...

http://www.advanced-driving.co.uk/drivi ... ead-depth/