[TheReaper]

Wear out the tread, how. As long as the L & R tyres on the same axle are the same circumference, I can't see how that would happen.

Having different depth changes the handling and stablility of the car, and changes the balance of the car being that they are at different depth. The car isn't running on a uniform plane, and you are angling the car front or back, depending on where you put the new tyres (usually should be done on the back axle). It's slight measurements, but it makes a big difference. I did do the two tyre thing a couple times and it always seemed that the tires didn't last as long, not  too much difference, but probably an extra 10-15000km loss than doing the 4

Sorry, but I don't agree. Angling the car one way or another is at best a technical description, that would only apply if you were driving on an absolutely flat surface. There are many distortions and angles of incline / decline to offset any variation, remember that we are only talking mm of difference.

The only difference I can see that could enter into the equation would be the wet weather performance and aquaplaning, obviously the rears would not be as good as new fronts. Now we have ESP & ABS to assist if necessary. I don't drive to extremes in any event.

but whether you were on an incline or a decline, your car in relativity to slope is still in a straight line, so the uniformity is still present with four new tires, 

[TheReaper]

pretty good debate but! Think I need a nicotine break!

[Phil №❶]

I think if I parked a car on any road where I live, none of the tyres would be on the same horizontal plane. It is not possible for a road making machine to even lay bitumen to the accuracy that you're describing, then there is wear and tear on the road surface, uneven compaction etc. so a couple of mills aren't going to be noticed. If the car is moving the suspension is constantly acting and reacting to road surface variations.

Cigarettes are bad for you. 

[TheReaper]

I think if I parked a car on any road where I live, none of the tyres would be on the same horizontal plane. It is not possible for a road making machine to even lay bitumen to the accuracy that you're describing, then there is wear and tear on the road surface, uneven compaction etc. so a couple of mills aren't going to be noticed. If the car is moving the suspension is constantly acting and reacting to road surface variations.

Cigarettes are bad for you. 

true. yeah and I need to stop smoking, but I consider it my happy drug. keeps me from thinking about kicking someone in the butt, from actually doing it! 

[Surferdude]

Wear out the tread, how. As long as the L & R tyres on the same axle are the same circumference, I can't see how that would happen.

Having different depth changes the handling and stablility of the car, and changes the balance of the car being that they are at different depth. The car isn't running on a uniform plane, and you are angling the car front or back, depending on where you put the new tyres (usually should be done on the back axle). It's slight measurements, but it makes a big difference. I did do the two tyre thing a couple times and it always seemed that the tires didn't last as long, not  too much difference, but probably an extra 10-15000km loss than doing the 4

Sorry, but I don't agree. Angling the car one way or another is at best a technical description, that would only apply if you were driving on an absolutely flat surface. There are many distortions and angles of incline / decline to offset any variation, remember that we are only talking mm of difference.

The only difference I can see that could enter into the equation would be the wet weather performance and aquaplaning, obviously the rears would not be as good as new fronts. Now we have ESP & ABS to assist if necessary. I don't drive to extremes in any event.

but whether you were on an incline or a decline, your car in relativity to slope is still in a straight line, so the uniformity is still present with four new tires, 

New tyre has 8mm tread. Should be replaced by 2mm (1.6mm is legal). So 6mm useable.. As a percentage of the overall diameter of the tyre it's negligible and will have no effect on the "balance" of the car.
As for putting the new tyres on the rear, I can tell you that is not accepted practice. It is certainly a prevalent misconception though.

[TheReaper]

How so? I can see that from a point of wear that you would not want to wear out the old tyres, since a front wheel drive wears fronts down faster. But as for, lets say, aquaplaning, you want the better treads  in the back. So you have better traction and push out the water more efficently. Since your front tyres lose control. If you have the new tyres in the front and aquaplane and have little tread in the back you could lose all traction.

[Surferdude]

How so? I can see that from a point of wear that you would not want to wear out the old tyres, since a front wheel drive wears fronts down faster. But as for, lets say, aquaplaning, you want the better treads  in the back. So you have better traction and push out the water more efficently. Since your front tyres lose control. If you have the new tyres in the front and aquaplane and have little tread in the back you could lose all traction.

But if you have the new tyres on the front you are much less likely to aquaplane in the first place.
Your steering is the most important end of the car, so, best tyres go there to give the best directional stability and grip when braking. Also, if you have worn tyres on the front, you are increasing the risk of a puncture up there. Worn tyres are something like 5 times more likely to pick up a puncture.
Do you REALLY want a tyre deflation on the front?

[TheReaper]

But the only thing is, if you do aquaplane with those new tyres on the front, and the ones in the back are low or somewhat low, you are out of luck. Sort of like gambling and going all in vs holding some chips back to cushion a lose. Most rain isn't going to do much in the way of aquaplaning, but we do get some crazy downpours. And as for punctured tyres. Most tyres that go flat are in the back. Usually nails get spun from the front tire going over them and shoot backwards. Not all the time but majority

[Surferdude]

But the only thing is, if you do aquaplane with those new tyres on the front, and the ones in the back are low or somewhat low, you are out of luck. Sort of like gambling and going all in vs holding some chips back to cushion a lose. Most rain isn't going to do much in the way of aquaplaning, but we do get some crazy downpours. And as for punctured tyres. Most tyres that go flat are in the back. Usually nails get spun from the front tire going over them and shoot backwards. Not all the time but majority

It sounds like you haven't experienced much in the way of aquaplaning.
And I can tell you you are wrong about where most punctures occur.

But, let's leave it go now.
You've got your opinions and I've got mine.

[TheReaper]

Lol, one more tidbit. Took my missus golf down a few weeks ago to work just to get a long run in, and was raining torrentially. And aquaplaned numerous times and it has a new set of tyres, with only 6000 km on them. I'm a medic, I'm in a vehicle for a living. Have more road experience and defensive driving than most. Try aquaplaning in an ambulance, patient loaded, scary as! Lol. But yeah, time to let this one go. Not going to change perspectives as it seems

[beerman]

Aquaplaning in an I30??? Seriously.....

Had a few bits of fun in the Falcon, but never in the I30.....

[TheReaper]

Nah, just talking in general,  of where tyres should go and to get just the two, or four. Skim up. Been debating since this afternoon. Haven't had problems with the i30 yet, but only have had it for about a month

[Dazzler]

@ TheReaper,

Being a new member (congrats by the way on the colour change - happened at 100 posts  ) you might not have noticed that Trevor (surferdude) is our Tyre Guru 40+ years in the tyre industry .. You are allowed to have your opinion but you won't win many tyre debates with Trev! 

You can be our first aid Guru! 

[Phil №❶]

Nice to see that no one got their knickers in a knot, over having different points of view.

& congrats on the 100 post milestone, Grim.

[beerman]

As an aside, what happens when all 4 tyres are low on tread? Because it seems that the argument stems around where to put too 100% brand new tyres. Wherever you put them, they will make a difference.

Apart from my first XD, where the dodgy front end had an appetite for tyres and putting new tyres to the rear was a way of getting more life from them before the inevitable wheel alignment/ball joint failure, my personal opinion has always been to put them to the front, because apart from the 0.01% of the time I might be subject to aquaplaning, I will be using the wheels to steer (and now drive) the car 100% of the time. If I do need a sudden change of direction in the wet under heavy ABS, I want the best tyres doing the heavy lifting.

That said, I now rotate my tyres to ensure they all die together, so I will replace all 4 anyway.

Hope nightwork was uneventful Reaper.

[TheReaper]

@ TheReaper,

Being a new member (congrats by the way on the colour change - happened at 100 posts  ) you might not have noticed that Trevor (surferdude) is our Tyre Guru 40+ years in the tyre industry .. You are allowed to have your opinion but you won't win many tyre debates with Trev! 

You can be our first aid Guru! 

lol dazzler

[beerman]

@ TheReaper,

Being a new member (congrats by the way on the colour change - happened at 100 posts  ) you might not have noticed that Trevor (surferdude) is our Tyre Guru 40+ years in the tyre industry .. You are allowed to have your opinion but you won't win many tyre debates with Trev! 

You can be our first aid Guru! 

lol dazzler

Reaper would have some good drugs too.....

[TheReaper]

Nice to see that no one got their knickers in a knot, over having different points of view.

& congrats on the 100 post milestone, Grim.

lol. No knicker knots here. I do love a good debate, and no hard feelings. And thanks! By the way, what are the milestones set at? And color changes? Sorry, don't have a computer at the mo. Using tapatalk,  which is not as good as the website

[beerman]

Shouldn't you be asleep?

[TheReaper]

As an aside, what happens when all 4 tyres are low on tread? Because it seems that the argument stems around where to put too 100% brand new tyres. Wherever you put them, they will make a difference.

Apart from my first XD, where the dodgy front end had an appetite for tyres and putting new tyres to the rear was a way of getting more life from them before the inevitable wheel alignment/ball joint failure, my personal opinion has always been to put them to the front, because apart from the 0.01% of the time I might be subject to aquaplaning, I will be using the wheels to steer (and now drive) the car 100% of the time. If I do need a sudden change of direction in the wet under heavy ABS, I want the best tyres doing the heavy lifting.

That said, I now rotate my tyres to ensure they all die together, so I will replace all 4 anyway.

Hope nightwork was uneventful Reaper.

if all four are low, you would be looking to replace them lol.

Work was completely uneventful.  Hopefully tonight will be the same. Got 6 and 1/2 sleep.

[TheReaper]

@ TheReaper,

Being a new member (congrats by the way on the colour change - happened at 100 posts  ) you might not have noticed that Trevor (surferdude) is our Tyre Guru 40+ years in the tyre industry .. You are allowed to have your opinion but you won't win many tyre debates with Trev! 

You can be our first aid Guru! 

And feel free to post on the site, or PM me if you got any medical questions. Don't know everything, but can point you in the right direction, and solve somethings

[Dazzler]

Nice to see that no one got their knickers in a knot, over having different points of view.

& congrats on the 100 post milestone, Grim.

lol. No knicker knots here. I do love a good debate, and no hard feelings. And thanks! By the way, what are the milestones set at? And color changes? Sorry, don't have a computer at the mo. Using tapatalk,  which is not as good as the website

1, 10, 100,300,500,1000,2000  (my next one is 40,000) 

[TheReaper]

 

@ TheReaper,

Being a new member (congrats by the way on the colour change - happened at 100 posts  ) you might not have noticed that Trevor (surferdude) is our Tyre Guru 40+ years in the tyre industry .. You are allowed to have your opinion but you won't win many tyre debates with Trev! 

You can be our first aid Guru! 

lol dazzler

Reaper would have some good drugs too.....

hahahaha. Yes Yes I do

[TheReaper]

Nice to see that no one got their knickers in a knot, over having different points of view.

& congrats on the 100 post milestone, Grim.

lol. No knicker knots here. I do love a good debate, and no hard feelings. And thanks! By the way, what are the milestones set at? And color changes? Sorry, don't have a computer at the mo. Using tapatalk,  which is not as good as the website

1, 10, 100,300,500,1000,2000  (my next one is 40,000) 

should have 300 in a week or so

[Phil №❶]

And so thankful, too. 

[Surferdude]

I've done some more research on this topic. When we last looked at it, some years ago, the same debate raged but there was very little stuff on the web favouring The Reaper's views, although for many years now the major tyre manufacturers have recommended new tyres to the rear in their publications. These days, there's a lot more to be found espousing the new tyres to the rear philosophy.

The manufacturers' position seems to relate to a general view that they could be held liable in the event of a serious accident caused by loss of traction in the rear. Why? Because you have all these driving experts who say it's better to understeer than oversteer.
I don't disagree with that. However, IMHO, what we're doing here is sacrificing a whole heap of day to day benefits in the off chance that a particular type of accident will occur.

ie. We're ignoring all the benefits of having the new tyres on the front in case we find ourselves in a situation where there is a loss of traction at the rear.

In the industry I've worked for most of my adult life and in which I spent the last 15 years or so (among other things) training the fitters and mechanics in workshop techniques, as well as the business owners/ managers in business management, most people will still  fit the new tyres to the front.

Why?

The weight is generally distributed somewhere between 55% and 70% to the front of the vehicle, so that's where all the work is done. This is magnified under braking. So, steering, braking, load carrying - AND - water penetration.
If there is standing water (little golfing term there    ) on the road, the front tyres obviously hit it first. If the tyre is well designed, it will pump most of that water out to the side (anything up to about 7 litres per second - think about that - 3 and a half 2litre milk bottles of water EVERY SECOND). Per tyre! So, in effect, they are helping pump the road dry for the rear tyres following.
You can picture that when you're driving on wet roads in traffic and you can clearly see the drier tracks on the road ahead from the cars in front of you.

Even back in the early to mid 2000's when most of the training I did was for dealers in The Reaper's area of Newcastle and the Central Coast, this whole topic was guaranteed to generate a lot of discussion. Including the Ford dealer who I think is now also the Hyundai dealer.

So, it's not going to go away anytime soon.

It's a matter of making sure that you're aware of the options and the results of those options. Then make a decision based on what you think is most likely to affect you.

At the end of the day, my personal opinion (and one I've explained to a lot of customers over the years - who've pretty much all agreed with me), is that constant good steering, braking and wet grip far outweighs a possible once in a lifetime situation, the risk of which is reduced by having the best tyres on the front.

I hope this massive screed helps to explain my position and help others make an informed decision.

Best case scenario? Replace all four at once.

[Phil №❶]

Agree with all of that 100%. With ESP becoming more common on vehicles, even the slight possibility of a rear end lose, is now a reduced likelihood.

[rustynutz]

Glad you bought all that up, Trev as I'd researched too and found the "accepted practice" to be the complete opposite to what you'd said.... 

[rustynutz]

Install Two New Tires on the Rear Axle - YouTube

[Phil №❶]

I'd rather catch a car with a rear tyre deflation than a front tyre any day.

The vid doesn't present all the possible scenarios. It would be possible to show the reverse without too much difficulty IMO.