new tyres front or rear?

[tonyh1950]

Hi,
After a discussion with the guy that looks after my car re the fitting of two new tyres I seek views from the forum as to whether they should be fitted to the front or the rear of a front wheel drive vehicle. I seem to remember hearing that they should go on the rear to avoid the rear breaking away and the partly worn to the front as they are the driving wheels. A rear wheel car may have totally different characteristics as the steering needs the grip so will need the new tyres on the front. Can you help please.

[Kevin]

Hi,

This may help: http://www.youtube.com/watch?v=l5YsQ_a_ijA.

[ScoobyChris]

Mine go on whichever axle the worn ones came off and no tyre fitters I've used have ever suggested I do otherwise. It's been well debated on here before and I am certainly not an expert

Chris (currently shopping for new front tyres)

[Kevin]

From the Kwik-Fit web site:

In the unlikely event that a tyre deflates suddenly, then it is easier to control the vehicle if this occurs at the front of the vehicle. For improved handling and stability it is now recommended that the ‘best’ tyres should always be fitted at the rear of the vehicle. This is irrespective of whether the car is front or rear wheel drive.

Because of this at Kwik Fit we do not recommend tyre rotation and we do recommend fitting your best tyres at the rear of the vehicle. If you are replacing a single tyre then this should be paired with the rear with the tyre having the most tread depth. There are some circumstances when this advice does not apply, such as;

Where front and rear tyre sizes are designed to be different
Where a vehicle is designed to have directional tyres at the front and asymmetric at the rear

Check your vehicle's handbook to see if there are any specific requirements, if not the best tyres should go on the rear.

[Gareth]

Mine always go on the rear - I tell the fitters what I want, as it's my neck on the line.

[SeanP]

I've always put new tyres on the rear on both cars (one FWD, one RWD).

I had not seen the VBH video before, but it is a perfect demonstration of the reasons I understood this to be the "best" way.

I don't see how one can avoid "rotating" the tyres (especially as FWD tend to wear out the fronts first) - but I always ensure that is done "rears to front" on same side, not switching across axles.
In fact, on my RX-8 I strive to rotate half-way through anticipated tyre life - to ensure the "best" remain on the rear!

[TripleS]

Post deleted.

[Astraist]

My view on the subject is that the good tires go - on all four wheels period!

Regardless of the drivetrain, putting worn or simply old tyres on one axle will reduce it's grip levels more substantially than any other variant (worn dampers, wheel alignment, balance, etc...) and make it more prone of sliding. Even a difference of one year of age, regardless of milleage or tread wear, can have an effect!

It's important to mention that worn tyres will not alter the car's natural handling characteristics: All modern cars are adjusted for an inherent understeer (when driven "on the throttle") and if the rear tyres are very worn or aged, the car will not naturally lean to oversteer but, once the required measures are taken (sudden closure of throttle, sudden braking or sudden throttle in a RWD) the oversteer would build up faster and be much stronger than it would be with proper tires.

Having the good tyres on the rear isn't much better either, due to an increased understeer (which could also turn into oversteer very suddenly) but also and mainly - Dramatically increased stopping distances. Another problem with having the good tyres on the front or rear, is that the ability to perform regular tyre rotation cycles is effectivelly eliminated, along with it's various advantages.

As I understand it, the latest advice is to avoid rotating tyres. Tyres "bed-in" to their placement on the car.

Tyres don't 'bed' into a specific place on the car, but rather to a certain direction of rotation (assuming they already have enough miles on them prior to the first rotation). To solve this, one should remove the tyres from the rims, which is a good oppurtunity to have them inspected all around, and than have them fitted on the opposite rim, e.g. front-left tyre to rear-right rim. This way, not only is the direction of rotation maintained, but the tyre gets rotated over the rim, so that the worn outer shoulder is now inserted towards the inside.

The only excpetion is with assymetic tyres, which are rotated simply by moving the front pair to the rear, again while keeping them in the same direction of rotation by rotating them on the rims.


Returning to the original subject, if the differences between the tyres are significant enough to lead one to wonder as to where to put the good pair - than all four tires need to be replaced! Differences of under eighteen months or 9,300 miles are not considered substantial.

[tonyh1950]

Thanks for all your responses re this question. I do find that with a FWD vehicle the front tyres do tend to wear quicker
( that could of course be the way I drive ) and so I have always insisted that the original rears get changed to the front and the new ones get put on the back, that way I always have the better grip on the rear. My logic being that the drive wheels with the traction can compensate for the slight wear. I haven't notice significant if any understeer and feel that it is easies to deal with than a sudden increase in oversteer when the rear wheels loose grip.
I still have to convince the mechanic.
This actually raises another point re worn tyres, would you run a vehicle with the minimum tread depth of 1.6mm on the front wheels of a FWD? Perhaps not in the current weather conditions and what would you consider the safe minimum tread beyond which you would change the tyres?

[waremark]

My view on the subject is that the good tires go - on all four wheels period!

Remind us how good is good. At what tread depth or age do you change your own tyres? (I most often have different sizes back and front, so am used to replacing my tyres in pairs and putting the new ones where the old ones came from; my target is about 3mm. I cannot imagine replacing all four tyres if those on the driven wheels have worn at twice the rate of the others).

[Gareth]

what would you consider the safe minimum tread beyond which you would change the tyres?

I tend to change about when legally obliged to do so ... in the past I have sometimes gone beyond that point without realising. Having said that the last time I got a pair of tyres fitted the ones that came off were 2.5-3 mm.

There's not a clear point at which you should change so far as tread depth is concerned, legalities aside, and it wasn't so long that 1mm was the minimum requirement, but people often talk about changing at 3 mm since the ability to cut through water is said to become noticeably worse below that.

Certainly it was the feeling of reduced grip on very wet roads that triggered my last change of tyres.

[TripleS]

Post deleted.

[Kevin]

This actually raises another point re worn tyres, would you run a vehicle with the minimum tread depth of 1.6mm on the front wheels of a FWD? Perhaps not in the current weather conditions and what would you consider the safe minimum tread beyond which you would change the tyres?

I'm currently running with tread just above the legal minimum of 1.6mm, probably somewhere between that and 2mm, in snow, but only because the car is a company car and the lease company seem very reluctant to change tyres unless they've squeezed the last drop of mileage from them. I've been keeping a careful eye on the tread depth and intending to go to the local Kwik-Fit to get them changed, when along came the snow.

The result, the car is a nightmare to drive. On Sunday I was travelling very slowly around a bend (much less than 10mph) on a slight up-hill section of road, trying to get traction, when it decided to grip and I went into the kerb. The front N/S alloy is now dented and will have to be replaced, so the moral of the story is, don't let your tread depth get too low if you have any intention of going out in the snow and ice. I think if I'd had more tread depth I'd have had better control.

On a happier note, I did enjoy watching the BMWs sliding about in the Sainsbury's car park. I offered one guy a push, but he declined and he did manage to get going eventually. At least I found it easier to get moving (but not much easier) than the BMW drivers.

[Slink_Pink]

As the tyres are the only thing that keeps me on the road, I always change at 3mm and always put best on rear. Both stem from current advice offered by manufacturers.

[Astraist]

The legal tread limit is unsafe in any and all conditions. A good, safe tread depth is at least three millimeters deep, if not four millimeters (especially in conditions like those in the UK). Even a wet road can be wet in parts due to plant irrigation, water bleeding of the pavement, local rain or what else. Also, the road might be heavily coated in dust, muddy or covered in sand or gravel, not to mention snow, ice, frost and hail.

Even on a perfectly dry surface, a worn tyre is no good. The tire will not necessarily grip more, because it wasn't intentionally built as a slick tyre. It was constructed as a treaded tire which got worn off to a point where internal layers of hard-compound rubber, meant to hold the structure of the tyre rather than grip the pavement, are exposed.

This also makes the tyre voulnrable to blow-outs which could otherwise be prevented by the thicker layer of rubber or the tread voids that could channel a nail or even a pebble, as well as due to more heat build-up, which was originally supposed to be cleared through the tread voids.

Modern steel-belted radials wear little at the tread. Rather, they become unworthy of use in terms of grip and handling, merely due to the chemical changes that the rubber experiences over time, usually after merely three years of age or 35,000 miles. A tread near the legal limit is guarenteed to be degraded.

I repeat my stand which is that the good tyres go - on all four wheels!