Two new tyres - front or rear?

cregser

I had a tyre slashed and then another puncture within 9 days of each other. The new tyres are a different make but the closest the garage could offer.

At the moment, the new ones are on the left side and the car slightly drifts to the left (because of road camber? maybe I'm more sensitive to it). Should I fit them on the rear or the front?

My Dad says the front - which I presume gives me better steering but IMO increases the likelihood of rear skidding.

Some web sites say rear - which would give more assurance against skid but less grip at the front to control that power.

Anan1

Put them on the same end as the driven wheels. By the way, what condition are the other two in?

cregser

You mean rear-wheel drive so put them on the rear? Why's that?

The others aren't perpect (they've done 28,000km in about 2 yrs) but the thread dept seems fine. I'll have to give them a good look over.

Anan1

The reasoning is that cars are more likely to slide at the driven end because the driven wheels have to deal with acceleration as well as sideways grip. This isn't always the case though - some older Peugeots, although front wheel drive, are quite tail-happy. Remember also, though, that when braking the front tyres do almost all of the work. This is an argument for having the best tyres at the front. I'm assuming your car, like most, is front wheel drive?

sundodger5

Guys the new tyres should always go on the rear. only exceptions being VW and all other cars with ESP system fitted.
Most modern cars produce understeer. The driver is used to this and automatically compensates. If you suddenly put new tyres to the front with old/more worn tyres to the rear it changes the cars balance making the car more likely to oversteer.
don't believe me try driving with 4/5 psi out of the front tyres and then put the front tyres to normal pressure and drop the backs. It will feel unstable at bestand may swop ends.
Mind you some people like that whole sideways action.
Also check the cars owners manual as all the above advice is superceded by the guys who built the car.
The above is the recommendation from the tyre makers.
I worked in tyres for 15 years and read every peice of infirmation i could get my hands on so i know more than your average tyre fitter.

crosstownk

sundodger5 wrote:

Guys the new tyres should always go on the rear.

I'm not disputing your knowledge or anything, but I work in the fleet game and have tyres fitted on up to 10 cars a day and practically all fitters (nationwide) say "best 2 to the front" assuming FWD.

If replacing 2 tyres with the remaining 2 having 4.0mm remaining, why would the most worn go to the front? Given that with front wheel drive both drive and most braking effort is applied through the front wheels. I'm assuming here that most folks don't drive their cars to the point where they experience under/oversteer.

I'm just curious..............

Dilbert75

I can see arguments in the "best 2 to the rear" theory - but I always consider water dispersal as the biggest difference between new and worn tyres. Given that the front tyres will normally have more water to disperse (leaving a clearish track for the rear tyres) I normally put best 2 to the front.

sundodger5

the above advice is fact. the problem you have with most places selling tyres is that they don't give accurate advice. many places don't care what you buy or do as long as thay get money in the till.
I could tell you stories that would frighten the hell out of you that people do these things to cars and then think it is safe to drive on the public road.
When working as a manager in the tyre game i would explain about best to the rear to at least 90% of customers many just knew better than me and had them on the front even though i could show them it in black and white in michelin technical data books etc.
Imagine your average joe soap tyre fitter hitting that attitude day in day out. Eventually it gets to the point where they don't even bother starting to explain.
Same applies to speed ratings, load codes etc. Have even had arguments with main dealers who wanted to down spec vehicles by 2 speed ratings.
I would rather lose the business knowing i have explained it properly using all the knowledge at my disposal. Once that is done most customers are over 18 and can make up there own minds.
Regarding most people not driving hard enough to experience oversteer. Have you been on an Irish road lately...
If i get the opportunity i will try to get a hand on the info and copy it here. Maybe it is on some of the tyre manufacturers web sites.
Another interesting fact regards blow outs on vehicles.
The uk police did an experiment which was part of an advanced tyre course i was on. Most people think sudden deflation of a front tyre is the worst scenario.
Wrong most rear wheel blow outs result in the vehicle rolling over as catastrophic oversteer eventually sets in caused by trying to catch the wildly swaying rear end at speed.
Sorry for the long post.
Mark....
Just found this http://www.michelin.co.uk/uk/auto/auto_cons_bib_pqr_neuf.jsp
I hope it explains it better than i can. remember owners manual overides all. Particularly vehicles with ESP system(VW etc.)

crosstownk

sundodger5, that makes sense - thanks for the link & info - I'll bear it in mind from now on.............

Dilbert75

Likewise. I sit corrected.

Alun

Well, you learn something new every day! I know in the old days when most cars were RWD that everybody told you to put new tyres on the back, but I guess that I, like everyone else, assumed this was for better traction, and so when things began to switch over to FWD it was automatically assumed that the reverse would apply.

sundodger5

Glad to be of help. Even though i am out of the tyre game now i have a whole head full of useless info.
If i can help anyone with some technical knowledge don't hesitate to PM me.