I'm also in the minority group who believes fitting newer tyres on front.
It might be better that newer rear tyres give better handling on limiting condition, but I like to have better traction on driven (FWD) wheels most of the time.
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Those "worn but still legal" tyres have no tread pattern left across the centre of the tyre. I wouldn't those on either the front or rear axle of my car.
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I went to replace the rear tyres on the CRV this morning and cannot find anyone with stock of the Bridgestone Duellers 684 215/65 x 16 (OEM). Apparently there is a waiting list as Bridgestone are not making them fast enough! One tyre guy has been waiting over 2 months!
So now I have got to decide on what to change them too (as the rears are just above the wear bars but the fronts are fine). I mentioned the General Grabbers UHP that scored highly in the tyre tests but I am told they are ONLY a mid range tyre and I would be better with something like Pirelli. The General was rated higher than the Pirelli in the test.
Why is this so complicated and confusing and what is the actual difference between a mid-range and premium range tyre anyway (apart from the name) General are made by Continental I thought they were a very good manufacturer.
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I'm also in the minority group who believes fitting newer tyres on front. It might be better that newer rear tyres give better handling on limiting condition but I like to have better traction on driven (FWD) wheels most of the time.
You mean like the limiting conditions of the last few days?
I drive gently (Non VBH mode) in most situations but I will adhere to what several of the major tyre makes have posted and fit new ones on the back.
When it comes time to replace a pair of tyres ( FWD) it is no problem swopping backs to front and no problem with old old tyres left to rot on the back.
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I am not convinced. If my car starts to lose wet grip at the front end and those tyres are worn- I replace them.
Hey presto- car grips at both ends again. Why would the rear end then lose grip? Only if I drove faster than before IMHO.
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Pugugly's link to another thread is very informative! It also gives some explanation of why better tyres on rear is not sometimes a good idea.
Edited by movilogo on 08/01/2009 at 13:17
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My experience of loss of grip is as follows:
On RWD cars: always lose grip on the rear driven wheels in snow. Car tends to spin.
FWD cars: always lose grip on front driven wheels in snow an tend to plough straight on .
As a result, I always put new tyres on the driven wheels.
I do not corner fast enough in normal conditions to lose grip on rear wheels in a fwd car.. and in snwo and ice or very wet conditions, I drive very cautiously at speeds usually determined by the driver in front.
I would not drive a car as VBH did with tyres as badly worn as she had: front or rear wheels. In my view, they are dangerous in wet and undrivable in snow. ---- whichever axle they were fitted to.
So far in 40 odd years of driving I have spun rwd cars on snow. I have never (touch wood!) spun a fwd car on snow. And my ratio of years driving is approx: 15 years RWD to 25 years + FWD.
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I have never "lost control" of a car in 33 years and over a million miles in all weathers and conditions. I put the tyres where they are needed at the time. End of. Load of nonsense.
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I am definitely in the "put new on the front camp"
If my front tyres last 20-25k, but my rears are lasting 50-60k, surely that means the fronts are doing more in the way of gripping etc and are therefore being scrubbed quicker? Therefore surely it makes sense to put the deeper and newer tread on there?
For VBH to swing the rear out there, she must have been driving at the limit of adhesion. Not something I would tend to do.
I am sure there is a benefit for this to the tyre makers but I am still trying to work it out. Or am I just too cynical?
Let me see, say fronts do 20k and back do 60k
Therefore after 60k will have changed 8 tyres by changing fronts as normal.
Doing the tyre makers way
After 20k, fronts are scrubbed, 2 new on back and backs on front
"New" fronts won't last 20k as already been worn at back so maybe change after 35k?
Then again after 50k?
Oh I am lost - I am sure there must be a formula somewhere to back my cynical theory up!
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The advice of the car's manual should, of course, be followed.
>>the fronts are doing more in the way of gripping etc
You're missing the point. It isn't which tyres do more grip, it's what happens if a particular axle suddenly loses grip. For this reason, it doesn't matter how you drive - you have to accept that sometimes, the conditions might catch you out.
If the front loses grip, it's usually quite benign, and easily recovered. If the back loses grip, most people will spin and crash.
Putting the best tyres on the back is entirely consistent with both the Construction & Use regulations, and ECE regulations which aim to prevent rear wheel brake locking - other than the post 2004 requirements for ABS, there was never any ruling about preventing front brake locking. Now, why would the legislators be so concerned about the rear axle losing grip?
It's the sudden and unexpected that's the important thing. I'm sure that many of us can drive a RWD car in a provocative manner, and make the rear axle lose grip, we can catch the behaviour, and look smart. Bravo! How many of us would have the correct rapid reactions if the event were unplanned, and unexpected?
In extremis, the required reactions to losing front end grip are far more natural.
As ever with this groudhog day like topic there will be those who persist in knowing better than the tyre manufacturers.
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You're missing the point. It isn't which tyres do more grip, it's what happens if a particular axle suddenly loses grip.
OK, to change things slightly. I have been driving for 22 years almost exclusively FWD apart from my dad's Carlton in my early driving days.
Every day I drive, I use the front tyres to steer me, to drive me and to be the first port of call at any ice/rain/greasy hazard. I cannot remember a single time that I have lost the rear end through lack of grip unless in controlled circumstances eg I knew the deserted car park was icy and was trying to put back out in a spin. Every time I am driving in a straight line, the backs are only going where the fronts have already been.
And that is also through only changing tyres, on whatever axle, as and when required. So for 22 years, I have driven with part worn tyres on rears and they have never stepped out of line. I am either a very defensive driver, or the "news to the backs" theory, IMHO, is only for extremes of driving.
And would I be right in saying that in the example on the video, if this was a straight line that she was driving, rather than a bend, and you were having to brake hard, you would want the better tread on your front tyres rather than back?
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I've only had the rear end slide out once. I managed to react to it - skid pan lessons have their uses. I certainly wasn't pushing very hard: a wet road, mid corner bumps and the Golf tail stepped out. Almost certainly due to the newest tyres being on the front. We all make mistakes, and despite training, not just on skid pans, I am well aware that losing the rear-end is not always recoverable.
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>>I use the front tyres to steer me,
As I've explained above, all 4 wheels are needed to make a car change direction. Yes, the front wheels turn around their swivel axis, but all 4 need to develop appropriate side force to turn the vehicle.
So, you use all the wheels to steer you, front AND rear.
>>to drive me
Yes, but usually you plan to apply traction, and it isn't something unexpected.
>>first port of call at any ice/rain/greasy hazard.
As above, you need all 4 wheels developing side force to steer.
>>I am either a very defensive driver, or the "news to the backs" theory, IMHO, is only for extremes of driving.
No, it's just that the margin against losing rear axle grip is larger, with good reason, than that for the front axle (phrased another way, *all* modern cars fundamentally understeer). The best tyres to the rear policy simply aims to maintain and maximise this safety margin.
>>And would I be right in saying that in the example on the video, if this was a straight line that she was driving, rather than a bend, and you were having to brake hard, you would want the better tread on your front tyres rather than back?
No. If you'll permit an analogy to the mathematics involved, losing front wheel grip is a bit like a dart in normal flight. The dart flies straight on. Losing rear wheel grip is a little like flying a dart backwards - it might fly backwards for a short while, but even the slightest purturbation will cause it to flip round. The same is true for a car braking in a straight line with a locked rear axle - it will flip round as soon as it encounters anything that provides a disturbance; camber being an obvious source of such a disturbance.
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I have owned cars whose ages ranged back to 1947, and I have never yet had one whose tyres wore down evenly on the same axle, despite careful adjustment. Invariably one or another has worn in advance of its twin, so I have periodically been in the position of needing to replace one, or sometimes three tyres.
I then do a general swap round to try and even up the treads on th same axle, sometimes throwing away the spare if one of the current cast-offs is marginally better.
Having always had RWD cars I just assumed that the better tyres should go on the driving wheels. It seems I was nearly right for the wrong reasons.
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And another thing - Bill touched on this earlier on but a scenario occurs to me. Some cars have different sized tyres front and rear. I know my brother in law's BMW does for example. So here's the thing. You have 7mm of tread left on the rears on such a car. The fronts are down to 2mm. You want new fronts. You can't put the rear wheels/tyres on the front because they won't fit. Does the tyre retailer try to make you have four tyres?
Laughable.
Edited by Humph Backbridge on 08/01/2009 at 14:33
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>>As ever with this groudhog day like topic there will be those who persist in knowing better than the tyre manufacturers.
>>
Nicely put. I agree.
>>.
..Some cars have different sized tyres front and rear.
>>.... The fronts are down to 2mm
>>.... Laughable.
Not how I would describe the situation on what is probably a high performace car.
The vast majority of cars are not shod this way.
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If you are going to quote may I respectfully suggest that it is not done so selectively as to potentially mislead a reader as to the original point?
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If you are going to quote may I respectfully suggest that it is not done so selectively as to potentially mislead a reader as to the original point?
I apologise. You have a valid criticism of my posting.
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Thanks H, ( virtual handshake )
;-)
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As ever with this groudhog day like topic there will be those who persist in knowing better than the tyre manufacturers.
Of course all manufacturers of any product will tell you their theory is best!
Baby milk is better than natural
Premium fuels better than normal
Premium beans better than supermarket own etc etc
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>>Of course all manufacturers of any product will tell you their theory is best!
Yes, but how do the tyre manufacturers gain from this?
If your front tyres are worn out, you'll buy 2 tyres. Having them fitted to the back, and the tyres from the back moved to the front isn't putting any more money in their pockets is it?
This is one of those (all too rare in modern Britain) cases where the advice is not given to line anyone's pocket, there are good technical reasons, as explained in my posts and on websites like Michelin's.
If anything, the advice leads to fewer tyres being scrapped fropm rear axles because of age related perishing of the rubber - the advice possibly means reduced numbers of tyre sales!
Edited by Number_Cruncher on 08/01/2009 at 15:18
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Car A (FWD)
Front: 8 mm
Rear: 5 mm
Car B (same make & model)
Front: 2 mm
Rear: 4 mm
Which car will be safer? Car A - isn't it? Do you suggest car A to swap tyres between front & rear and let car B remain as it is?
The more relevant question is at what tread you change tyres - not whether to put newer at front or back.
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>>Which car will be safer?
Of course, car A, it has more tread all round.
Car B with its front tyres at 2mm needs some new ones on, which should go to the back, and the 4mm ones at the back go to the front, with the owner being advised that they need to keep an eye on them.
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So, question can now be stated like
what is the marginal tread depth when you need more treads in rear tyres than front?
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>>when you need
There is no need, no law, it's simply a best practice recommendation to maintain a margin of safety.
In the same way that wet grip deteriorates rapidly below 3mm tread depth, and only a skinflint would wait until their tyres were at 1.6mm before replacing them.
It's odd, the best practice advice to change tyres at 3mm tread depth, which does clearly increase tyre sales, does not attract anything like the same post count as this topic on this forum. More heat than light in the Backroom, as ever!
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>>Of course all manufacturers of any product will tell you their theory is best!
>>Baby milk is better than natural. Premium fuels better than normal. Premium beans better than supermarket own etc etc
>>
I do not understand your comment. This is not about product quality, mine is better than yours etc.
IMO These major tyre makers would not publish statements about where to fit tyres unless they were very sure of the legal situations that could arise if they were wrong.
The same generally applies to other associated companies connected with tyres.
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The test relates to FWD. Are there any FWD cars with different sized tyres front and back? I can't think of any.
BMW, MB, smart, Porsche and other high performance vehicles are the only ones which sprint to mind - all RWD.
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>>The test relates to FWD
Front wheel drive / rear wheel drive is a red herring in this regard. The best tyres need to go on the back axle regardless.
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Honestly not trying to be deliberately controversial here, but has anyone here ever actually had an accident or heard of one as a result of having more tread depth at the front than the back?
I have, however, heard of and witnessed plenty of accidents caused by vehicles ploughing straight on due to loss of front end lateral grip or even straight line grip but seldom if ever of anyone finding themselves with the back end so out of control in normal driving that it could not be easily corrected with a dab of opposite lock. Loss of front end lateral grip conversely tends to aim the vehicle inexorably at a non intentional destination.
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HB - I recently had a very lucky escape where the rear end of my FWD car suddenly broke away on a sharp bend on a motorway slip road. Fortunately the car spun completely off the road, otherwise the following HGV would have almost certainly hit me.
At time of my incident the rear tyres were worn but legal whereas the fronts were fairly new. I always used to put new tyres on the driven wheels, but now firmly believe that they should always go on the rear.
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