Two New Tyres - front or rear

[Gary]

Ladies,
I'm talking about S2 tyres here. Remember that one of the 100 improvements in the S2 was the lower profile tyres

[Enright]

Good poll too!

I've removed the "Who cares!... It's only Gary" option.

Can you replace it please? I want to change my vote!

[Breed]

Gary

If your buying Michelins, worth the money by the way, why not do as they recommend. Extract from their web site is below. IF you don't believe what they say why buy their tires in the first place



Whether you have front or rear wheel drive, we recommend that you use newer tyres for the rear set, for extra safety in unforeseen or difficult situations (emergency braking, tight bends etc) particularly on wet surfaces.

Numerous tests have shown that it is easier to control the front wheels than those at the rear.

Front tyres generally wear quicker than those fitted at the rear, particularly on front wheel drive cars, which are currently in the majority.

New tyres fitted in front :
- The behavior of the car will change, because the front / rear balance will be reversed.
The driver, used to a car with less grip at the front, will therefore be taken unawares.
- On a slippery road, the rear will lose traction before the front of the vehicle.
The driver will have no chance of controlling the rear, and will be tempted to accelerate further, which will amplify the spin effect. Only an experienced driver will be able to recover from this dangerous situation...


New tyres fitted at the back :
- The handling of the vehicle will be similar to that known by the driver before the tyre change, because the traction balance will be the same.
- Rear traction will be better, and the driver will be able to control and steer their vehicle without a problem by decelerating and turning the steering wheel in the direction of the bend.

That's why Michelin advises you to reduce the risks you take by fitting new or less worn tyres at the rear of the vehicle for:
- better grip on bends
- extra safety.


Also car mechanics have a few pages on it and this may be of interest as well

"Some tire dealers have been sued for putting the new ones on the front when the customer later had a spinout accident."


Its easy for us to say what is better sometimes. Even bald tires give better grip under some circumstances.

Over to you Ray I am sure you will tell us why Michelin know nothing about tires javascript:emoticon(':wink:').

[Gary]

I think that sums it up then - rear !

[RayD]

Hi Bill,

I've just re read the 970 words I've written on the subject and I can’t see the ones that have you thinking I’m likely to say Michelin know nothing about tyres... When you say “I am sure you will tell us” you are making it sound as if I’m at odds with the other 2400 members”.

or were you just kidding?

I've got four new Michelins on my car.

I’m trying to be helpful, as I’m sure you are. If there is something I've said out of turn let me know what it is, I’ll be the first to apologise.


As for the Michelin write up, there are parts I don’t understand... I’ll have another read.

Ray

[Breed]

Ray

Only kidding with a little sarcasm thrown in. Please do not take the last line seriously.

Bill

[tweetdriver63]

Gary

If your buying Michelins, worth the money by the way, why not do as they recommend. Extract from their web site is below. IF you don't believe what they say why buy their tires in the first place



Whether you have front or rear wheel drive, we recommend that you use newer tyres for the rear set, for extra safety in unforeseen or difficult situations (emergency braking, tight bends etc) particularly on wet surfaces.

Numerous tests have shown that it is easier to control the front wheels than those at the rear.

Front tyres generally wear quicker than those fitted at the rear, particularly on front wheel drive cars, which are currently in the majority.

New tyres fitted in front :
- The behavior of the car will change, because the front / rear balance will be reversed.
The driver, used to a car with less grip at the front, will therefore be taken unawares.
- On a slippery road, the rear will lose traction before the front of the vehicle.
The driver will have no chance of controlling the rear, and will be tempted to accelerate further, which will amplify the spin effect. Only an experienced driver will be able to recover from this dangerous situation...


New tyres fitted at the back :
- The handling of the vehicle will be similar to that known by the driver before the tyre change, because the traction balance will be the same.
- Rear traction will be better, and the driver will be able to control and steer their vehicle without a problem by decelerating and turning the steering wheel in the direction of the bend.

That's why Michelin advises you to reduce the risks you take by fitting new or less worn tyres at the rear of the vehicle for:
- better grip on bends
- extra safety.


Also car mechanics have a few pages on it and this may be of interest as well

"Some tire dealers have been sued for putting the new ones on the front when the customer later had a spinout accident."


Its easy for us to say what is better sometimes. Even bald tires give better grip under some circumstances.

Over to you Ray I am sure you will tell us why Michelin know nothing about tires javascript:emoticon(':wink:').

It says "whether you have front or rear wheel drive," but when you read it, most of the justifications given don't actually make sense with a front-drive car. This part, for example:

"The driver, used to a car with less grip at the front, will therefore be taken unawares.
- On a slippery road, the rear will lose traction before the front of the vehicle.
The driver will have no chance of controlling the rear, and will be tempted to accelerate further, which will amplify the spin effect."

In a front-drive car, that's exactly what the driver should do. The temptation to back off the accelerator is what would be bad. That results in "lift-off oversteer," which, of course, is the rear slipping out, which would just make the above situation worse.

I find this whole discussion fascinating, but I'm having some difficulty getting my brain around this concept. There is no way the configuration of the car (engine location and drive wheels) doesn't have a huge effect on where the better tires should be. I really think they're being slow to catch up with the change to front-drive, after many decades of all rear-drive cars.

Please, somebody, convince me.

[Breed]

Hi chris

You may not have read it right.

What they are saying is that the fronts wear faster than the back on FWD cars. Therefore over a period of time you get used to driving with less grip at the front. If you then put new tires on the front you will reverse the front to rear grip you were used to. This can catch you out. Most cars have understeer built in as it is regarded as safer in the average persons hands. F1 cars have tendency towards oversteer which is why they drive backwards a lot when they lose it. F1 drivers are far superior to us at driving (Except Hamilton) but when the back overtakes the front most of them lose it.

You will not stop oversteer with a bit of throttle on is own and very few people take skid pan training to get it right. Anyway for most people by the time the brain has worked out what's happening you have probably hit something. Too much accelerator = faster spin.

Just as the Elan was built so that 90% of the people could drive it well 90% of the time. It is the same with tires, major companies probably look at what is best most of the time for the average driver. Me for instance.

Bill

[DeeAitch]

I only paid a bit more for mine £70 + vat for all the works

Where from Rambo? I need 2 new ones - for the rear of course

[RayD]

Bill,

I wrote this before I turned the internet on, Sorry if its out of context with yours, and Chris’s posts

If you look back, you’ll see I started by asking where it came from, not by disagreeing with it... apart from saying I could make safer, quicker progress with the best tyres on the front from a choice of two new, and two bald ones.

Otherwise I've said I don’t think it will make a lot of difference one way or the other, under normal circumstances.

Here’s my comments on the Michelin write up you were looking forward to...

New tyres fitted in front : The behavior of the car will change, because the front / rear balance will be reversed.

This is the bit I didn’t understand – If a person generally kept the best tyres on the front, how would it change if you put the best tyres on the front?

The driver, used to a car with less grip at the front, will therefore be taken unawares.

A measure of this statement being true is whether you would personally like to be cast in the role of the ‘driver’. You would be insulted if I suggested you would be taken unawares if someone fitted tyres with a newer tread on the front of your car. How do these people go on when they get in someone else’s car? Or their other car. Or directly after a service when the tyres have been changed over?

On a slippery road, the rear will lose traction before the front of the vehicle.

I’m not sure about this either. I’d never looked upon it has ‘traction’ on the rear wheels of a front wheel drive car.

The driver will have no chance of controlling the rear, and will be tempted to accelerate further, which will amplify the spin effect.

This is just rubbish...again you wouldn’t like to cast in the roll. Drivers are not tempted to accelerate further, its the last thing they feel inclined to do. It wouldn’t amplify the spin effect in a Lotus Elan.

Rear traction will be better.

Someone might be able to explain this but I’m not sure it is traction on a front wheel drive car.

...and the driver will be able to control and steer their vehicle without a problem by decelerating and turning the steering wheel in the direction of the bend.

They even gloss over this in the first driving lesson; a child of two is able to do it.

"Some tire dealers have been sued for putting the new ones on the front when the customer later had a spinout accident."

How did they go on in court with 80% of the bench and jury thinking it was a good idea? (Albeit wrongly as it turns out)

Its easy for us to say what is better sometimes. Even bald tires give better grip under some circumstances.

Out of interest what are the circumstances? (Disregarding racing slicks)

Ray

[Gary]

Surely bald tyres give better grip in the dry ? (i.e. effectively they are slicks), but come the rain they are hopeless...

[Breed]

last comment on this subject.

Read what is posted and not what you think has been posted.
Gary is right on the bald tires bit.
The four most important bits of rubber on the car so I will go with manufacturers recomendations. There is so much about it on the internet and all maunfacturers go for rear wheels and I am not prepared to think I know better.

Bill

[dapinky]

Hang on a minute - i just need to check if i am allowed an oppinion on this thread................



....Yep, it seems okay to continue


I have been following all of these points with lots of interest (from a professional point of view, as well as a personal one)

Now, I'm not suggesting that i know anything like as much on the subject as Monsieur Michelin, but, like Ray, some of the statements made appear to be either badly worded, or just incomprhensible to me (being a mere mortal with a little bit of knowledge).

I am sticking with my earlier statement that "I just don't know the answer" but have some observations to make:-

In the field of Accident Investigation and Vehicle Examination (in which i hold the relevant qualifications, and thus I'm officially an 'Expert' - PLEASE DONT CONFUSE THE CONCEPT OF 'INSTRUCTION' BEING THE SAME AS 'KNOWLEDGE' OR 'EXPERIENCE' - I actually realise that accepting what I've been told doesn't equate to being correct - I 'know' less than a Barcellonan waiter in a Torquay Hotel).

As i see it, any tyre (or tire ) degrades with age/use/conditions, and what is a good one today, may well be cr@p next year.

Likewise technology moves on, and a mid-range tyre from current supply, may well be as good as, or better than, a 'top quality' one from 17 years ago .

I'm sure someone summed it all up with "Buy the best you can afford", but i still say, "Stick within the limits of the car, road and driver".


On the point about totally bald tyres, there are differing opinions - i can only go on what i have been taught by the man from the forensic science department at Goodyear Tyres (He *SHOULD* know what he was on about - but as i say, things change, and he, generally, would have been referring to products made by his company).

1) On a dry TARMAC road, a bald tyre will grip better than a treaded one as there is a greater contact area.

2) On a slightly damp TARMAC road, it dont! (Untill you lock the wheels, then the heat generated from the skid may dispell the moisture),

3) On a CONCRETE road surface, it all goes wrong - there is less friction, so less heat builds up.

That said, TARMAC (and concrete) both have a friction co-efficient of 0.72 in the dry, but in the wet we still take 'test results' as each compound reacts differently to water.

The next issue, is during the skid itself - as heat builds up between the tyre and the road, bits of rubber on the tyre surface will melt, causing a 'wet patch' between the road and the tyre - this is what leaves the top skid mark - and gives the same effect as aquaplaning.

If the road is TARMAC, then oil will bleed out of the road surface as well due to the heat, further exacerbating the effect - this is why skid marks 'develop' after a skid and often get longer - this is the second-level skid mark.

On Concrete, there is less heat build up and no oil to bleed out, so what you see is what you get, and it's all from the tyre.

All of this is great in theory, but then you throw damp leaves, spilt diesel and squashed rabbits into the mix - it's a bloody nightmare!

The upshot is, all things being equal, on a dry road surface you stop quickest when the tyre is just on the limit between sliding and turning (ABS?) and has maximum contact with the road. This can be either a bald tyre in the dry, or a grooved tyre in the wet, but the 'downforce' on each tyre is also relevant - if there is no weight on that particular corner it doesnt have any effect (hence the point of this thread, as to where to put the good tyres for maximum effect).

It doesnt matter how good the brakes and tyres are if the car isn't even touching the road!

[Rambo]

I only paid a bit more for mine £70 + vat for all the works

Where from Rambo? I need 2 new ones - for the rear of course

It was my local garage Dave. I don't know where they sourced them from at that price but I had asked specifically for Yoko A538's which I had on the front. I fully expected them to be dearer for the Michelin Exalto's - perhaps they only charged me for the Yoko's ?

Incidentally they put them on the rear but that was to replace 2 Pirelli's with about 2mm tread each. That meant that I had been driving for at least 6 months with 7 - 8mm tread on the fronts and about 2 - 3 mm on the rears And I didn't notice the slightest difference !

[Gary]

The next issue, is during the skid itself - as heat builds up between the tyre and the road, bits of rubber on the tyre surface will melt, causing a 'wet patch' between the road and the tyre - this is what leaves the top skid mark - and gives the same effect as aquaplaning.

If the road is TARMAC, then oil will bleed out of the road surface as well due to the heat, further exacerbating the effect - this is why skid marks 'develop' after a skid and often get longer - this is the second-level skid mark.

With all this going on I bet they'd be other skid marks too !

[RayD]

Ray

Only kidding with a little sarcasm thrown in. Please do not take the last line seriously.

Bill

No problem Bill,

Thanks

Ray

[Breed]

Dave

You missed your calling you should have been a politician.
All very interesting but your answer to the question of whether 2 new tyres are better off on the front or back is?

Bill

[dapinky]

Bill,

If you actually look at my posts I have clearly stated what this party believes to be the only correct answer.........

....but I'll say it again anyway......


"I just don't know!"

[RayD]

Hang on a minute.................On the point about totally bald tyres...

Thanks for that Dave... you learn something every day... particularly the bit about skid marks getting longer, later.

To answer my other question... having looked around the Internet it seems the original idea of having the best tyres on the back came from Michelin in 2004. Other people may have just quoted them.

While their report is badly worded and wrong in places I imagine there must be something in it.

It’s so badly worded it may have been wrongly translated from a foreign language.

While I’m all for changing all four tyres at once – if my son’s A Class wanted two new tyres this afternoon I’d have them put on the back - just on the strength of the recommendation, and the thought it wouldn’t do any harm.

On the other hand... I could make more progress, for longer with two new tyres on the front and two bald ones on the back of a Lotus Élan than I could the other way round.

Another thing that may have been lost in translation is the idea it is better to go off the road forwards, rather than backwards. (the dangerous tendency to oversteer)

For anyone who hasn’t had the opportunity...if you ever in a position to choose, choose backwards.

I think I’ll pack this in... I can’t do with the aggravation.

Ray

[Foo]

Well, I've just gone against this advice and am having 2 tyres fitted to the front, but my situation might be different:

Setup is currently 2 front P7000 and 2 rear PZero Nero

I've found a puncture in the rear offside this morning and managed to limp it up to a tyre place nearby.

I'm replacing both rear tyres with Exalto PE2s, but I'm having it swapped so the P7000 sit on the rear and the Exaltos up front.

My reasoning for this is the P7000s look quite new and have a lot of treat left in them. Plus most of the benefit from the PE2s is in putting power down and steering response... to my mind, it makes more sense to have that up front. Expecially as it's £230 fitted

Not really comfortable mixing tyres like this but the axles match so I think it'll be fine. When the P7000s wear out I'll replace those with PE2s as well, if the current ones are good.