Tyres

[jont]

Might seem like a silly post, but as these round black things are the only thing that keeps us on the road and I'm about to replace all the tyres on SWMBOs car, I've got a few questions...

In another thread Stressed Dave was suggesting that the compounds used in tyres don't differ a lot. So what are people experiences of different brands? How much is it actually worth paying for a set of tyres? Are premium brands worth the extra money?

It seems like this can be a bit of a religious debate, so I'd be grateful for scientific explanations wherever possible. On another forum I frequent, the cheaper brands are known as TDFs - Taiwanese Ditch Finders. On most occasions where someone has had an incident with the scenery, they have had cheap tyres on their car. Is it actually related to the brand, or is it more likely that someone who skimps on tyres also skimps on driving appropriately for the conditions?

Facts I think I know:
Stopping distance dramatically increases in the wet once tread depth gets below 3mm.

My opinion:
I can't tell much difference between tyres in the dry, and behaviour probably has as much to do with correct steering geometry as tyre compound.
In the wet/on muddy roads I think I can definitely tell the difference between "cheap" and premium tyres.

Any thoughts?

cheers,

Jon

[Gareth]

I've been very impressed by Goodyear Hydragrip when driving in wet conditions, but I've noticed they aren't much additional help in snow! In the wet at normal temperatures, they feel almost as sure-footed as if it were dry. On the other hand, MarieArtie has been impressed with Goodyear F1's (GS-D2) in the snow as well as in the wet.

In another place I started an interesting discussion about the use of winter tyres in the UK, and most opinion was that the UK isn't cold enough to make it worth while. There were a few dissenting opinions from people who have used winter tyres and been impressed by the difference they perceived. If I had a spare set of wheels, I would be tempted.

StressedDave is very clear that remoulds aren't a wonderful idea for performance cars because, he says, the main characteristics of the tyre depend on the carcase construction, and remoulds have the same tread pattern added to recycled carcases from a variety of manufacturers. Having said that, if I had a car that was only going to be driven in a relaxed fashion, I would consider using Colway tyres.

[ScoobyChris]

Facts I think I know:
Stopping distance dramatically increases in the wet once tread depth gets below 3mm.

As I understand it, this only affects tyres manufactured in Germany (?) where the legal limit for tread depth is 3mm so this is the point where it should be replaced....

Pirelli PZero Nero's seem to be highly rated at the moment, but I've not had a chance to try them myself. I can say that the Michelin Primacy's I have on the front of my car at the moment are not as good as the Michelin Pilot Sports they replaced! And don't get me started on the Conti SportContacts.....

Chris

[jont]

if I had a car that was only going to be driven in a relaxed fashion, I would consider using Colway tyres.

Funnily enough, Colway Road Pluses are required for almost all enduro motorsport events. I've used Road Pluses on my road rally car, and the beefy sidewalls are good on white roads. I've had one friend who has had a colway delaminate, but his style is on the extreme side of exuberant (and it's entirely possible the tyre had been rotting in his shed for a couple of years before using it). The downside to the Colways is that they are very soft - we got through a set of front tyres on a 1l Uno in about 500 miles (mixed road/competitive use in snowy weather doing an enduro rally last November). I like Bridgestone RE720s, and also Goodyear F1s (although the newer GS-D3 pattern), but the sidewalls are soft and they don't cope as well as the Bridgestones in mud. Sadly none of these are available in the sizes my car current needs. In comparison to the Colways I got about 5000 miles out of a set of RE720s on my fronts on a 309 GTi - probably about 1000 competitive road miles in that.

Jon

[Angus]

The only experience we've had of "cheap" tyres was when kwik fit conned my wife into buying their own brand tyres ("just as good as pirelli but cheaper!") before she went on an HPC track day. She was not a happy bunny when she got home

Nor was the kwik fit manager when I'd finished with him

In general I'd suggest sticking with the brand that the manufacturer put on in the first place. A decent local independent will usually supply branded tyres for a similar price as the big chains charge for "premium Korean"

[manilva15b]

On tyre brand: You generally get what you pay for.

Note that the large premium brand companies also manufacture cheaper tyres. For example Michelin also make Kleber.

From time to time as the tyre companies introduce new compunds and/or tread patterns they sell off the 'old' technology to other companies. This is why you can find may reasonable tyres manufactured in Hungary or Poland as they are 10-year-old Michelin technology - perfectly reasonable for road use.

Some old tyre technology has also been exported to the far East, hence the number of Chinese tyres coming in which are much better now than a few years ago. Reasonable for road use if you're not enthusiastic.

Remoulds I would stay away from. I've heard too many stories on delamination to risk buying them. Years ago they were speed rated to 64mph, though I don't know if that is still the case.

One other point. If you have Michelin PAX tyres fitted you should only replace them with the same. There have been a number of cases of tyre failure reported where other tyres have been fitted.

Tread depth. The UK (and Spanish) limit of 1.6mm is laughably low. Performance and grip start falling off dramatically once the depth gets to 4mm (about 50-70% grip by this stage). I always replace my tyres at 4mm and will (and have) refused hire cars with less.[/u]

[Nigel]

I've never hear of, or experienced this magic grip loss at any tread depth.

The advertising seems to have worked on some.

Tread depth has nothing whatsoever to do with grip..........period.

It disperses water, should there be any to disperse.

I'd suggest your being a bad boy replacing your tyres at 4 mm, just think of the resources your wasting.

Whats with this 3mm in Germany ?, it was 2 last time I was based there.

[Gareth]

This is an interesting point - if we change tyres early, (as in having a greater tread depth), then unless we use remoulds we're not being very green!

[ScoobyChris]

Not sure where I got the 3mm from - thought I read it in a pamphlet in the tyre place's waiting room....

Here's what RoSPA advise....

MINIMUM TYRE TREAD DEPTH

Although the legal tread depth limit is 1.6mm, a threshold set by motoring experts some 13 years ago, there is now compelling evidence that motorists should check and change their tyres at 3mm. Wet road surfaces are one of the biggest threats UK drivers face.

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.

RoSPA is advising motorists of a four point tyre health check to help increase driver safety:

• Every two weeks check the pressure of your tyres when they are cold.
• Check the tread depth of your tyres. Although the minimum legal UK tread depth is 1.6mm, RoSPA recommends that tyres should be replaced when the tread depth reaches 3mm. As the depth decreases, stopping distances in wet weather will increase. This is more notable on cars with larger wheels and wider tyres.

• Check tyres for damage. Look out for any cuts, cracks or bulges as these can lead to slow punctures and blowouts.
• Finally, don’t forget to check the pressure and tread depth of your spare tyre.


Chris

[7db]

Tread depth has nothing whatsoever to do with grip..........period.

Tyre blocks squirm better when there is a greater tread depth as I understand it, so they behave more progressively when they let go, as I understand it.

[stuartb]

My experience is that there is a difference between tyres (don't know if its compound or construction) in terms of life/wear resistance, ride quality, noise and wet grip.

Dry grip I have less personal experience of because I don't tend to do anything which pushes any of my tyres that far.

This all varies quite a lot between tyres within manufacturers' ranges as well as between brands. For example, I have good experience of the Bridgestone S01s and S02s but the RE040 which is standard fitment on my car is universally despised by owners as anything other than a warm/dry weather tyre. They did last longer than anything else I've tried though on my current car.

I have recent experience of Pirelli Pzero Rossos, and Michelin Pilot Sports.

Both have been good. I am just about to replace again with the Michelins as they were quieter with other things being equal. I've heard others didn't like Pzeros in the wet, but I found them wonderful even in very poor conditions. FWIW I was warned off Neros by those in the know as being suitable for modded Saxos on a Saturday night cruise and nothing much else (I have nothing against modded Saxos per se by the way but you may get my point).

I had Contisports and Contisport 2s on my previous car. They were fine on that, but wet grip DID take a noise dive as they got more worn (whilst still very legal).

I believe this is true of the Michelins on my current car as well which are down at 4mm now.

I also believe that at least on my current car that tyres at this wear level become considerably more "tramliney" (my car has a bit of a tendency to this, but its much more pronounced - but it could be that its time for an alignment check).

I have had Toyos (T1-S) in the past which are a cheaper tyre. These were very good too.

Stuart

[manilva15b]

In defense of 4mm tread depth

Tread depth has nothing whatsoever to do with grip..........period.

It disperses water, should there be any to disperse.

I'd suggest your being a bad boy replacing your tyres at 4 mm, just think of the resources your wasting.

Your first two statements quoted here are contradictory - too much water for the tyre to disperse (related to tread depth) and the tyre aquaplanes = loss of grip. QED.

The information I am working from comes from Sweden (The TRL's latest report is can find on tyre performance is dated 1970), from an independent research centre.

The other replies concerning 3mm tread are somewhat conservative:

The issue of tyre tread depths has been back in the news recently. The latest test, by Auto Express magazine, showed that, in a 1.8 Ford Focus, the stopping distance in the wet at 70 mph was 91 metres with a tread depth of 3mm but 135 metres at the legal minimum of 1.6mm. Having tyres at the correct pressure, and replacing them well before the legal minimum is reached, is one of the most significant safety measures that those responsible for fleets can take.

If red is the opposite of green, then I'd rather be red than dead.

[Angus]

An aside to tread depth is mixing brands.

In this month's Car magazine they've reported on their long term MX-5 where they replaced the worn Michelin tyres at the back with Toyo They descibe the handling with the new tyres as "evil" and the car as "near undriveable"

They say that the Toyo tyres were £60 cheaper each than the Michelin and this obviously echos the "you get what you pay for" school of thought.

Angus

[ScoobyChris]

An aside to tread depth is mixing brands.

I'd never given a 2nd thought to doing this on my car (as it's not a performance car or 4wd) and it came with Michelin's up front and Conti's on the rear. I've never encountered any detrimental handling in any road condition with it. First time Don Palmer gets behind the wheel he comments that the car oversteers (it's a FWD Mondeo diesel!) which was interesting and once we reached the airfield, had some fun exploring it! I guess the Michelin's offer more grip?

When they come to be replaced though, I think I'll be getting 4 the same

Chris

[jont]

I'd never given a 2nd thought to doing this on my car (as it's not a performance car or 4wd) and it came with Michelin's up front and Conti's on the rear. I've never encountered any detrimental handling in any road condition with it.

When I bought a cavalier many years ago, it needed 2 new tyres. I had TDFs on the back, and put some new decent dunlops on the front. The first time it rained, I span it (lift off oversteer). Now Mk 3 Cavaliers are more known for understeer than oversteer. I now never mix tyres on an axle, and I try not to mix front/rear. (It was after that I decided I ought to learn how to handle LOO. Fortunately having access to an airfield at my gliding club provided plenty of opportunities when it was too wet to fly )

As for Toyo's being rubbish compared to Michelins, that's quite interesting as people on the MR2 forum often swear by Toyos rather than at them. I've currently got some on the back of my car as there's not a lot you can get in 225/50/15. They were rubbish for the first 1500 miles or so, but since then they seem okay - and I don't think my driving has adjusted to compensate for grip issues.

Jon