Rear tyres are wearing out real fast!

[GHS]

I have noticed that my rear tyres are wearing out so much faster than the front ones. The wear on the rear tyres are uniform (same wear for inside/outside on the same axle), so I assume that mis-alignment can be ruled out.I have religiously done an alignment/balancing/rotation job every 10,000km or so. I have recently done my 3rd one; so the front tyres are now with less thread than the rear.Facts of the suspension/tyres on my ride:Front: 20% thread, Rear: 50% threadCurrent tyre mileage: ~28,000 kmTyre size: 225/45 R17 all round (CSC2 RFTs, came with the E90)Lowered with Eibach Pro-KitQuestions:1) OK I know it's a rear-wheel drive car, but just wondering if it's normal for the rears to wear out so much faster? I don't do burn-outs that often to cause this...2) Will a lowered ride add to the tyre wear rate, especially the rears?3) A bad alignment job will cause wear either on the inside/outside of the tyre. But will a bad alignment job also cause accelarated uniform wear as well on the tyres? 3) I now have fronts with 20% thread, rears with 50% thread after my latest alignment/balancing/rotation job. I read from somewhere before that for normal road-going drivers like me, it is safer to have the rear tyres with more thread, as:more thread at the rear = more traction at the rear = less possibility of dealing with an oversteer situation which is harder to control. How true is this?4) Is it safe to go on track (i.e. the HPC @ Sepang next weekend) with the current setup - front 20% thread, rear 50% thread?

 

[chaiks]

Hi GHS,

You'd be surprise by the difference of one shop alignment to another. I have religiously stick with one shop for over 10 years in doing all my cars balancing and alignment. Even though it takes a long drive there.

One best example, was my last replacement of arms and mounts at a shop, and he proceed to send the car for alignment before handing it back to me. It does not felt right, and I immediately send it to my trusted workshop to do it. The ride was excellent again, and I trust him, cos he also own and drive an e39 like mine.

Tyre wear and tear is unavoidable, but proper balancing and alignment helps. But, frankly, nothing irks me most, than a car that don't handle right.

So, ask around and look for an experience alignment guy around your area who knows about continental car alignment, not proton. Especially, our ultimate driving machine.

Cheers.

 

[SarJeePekAi]

see below pls

 

[SarJeePekAi]

You going on track? I will NOW be backing out from my offer of sale.
Ok, I am opting out, many thanks and apologies..... ADIOS.

 

[ALBundy]

GHS, its perfectly normal for RWD to have the rear tires wear out faster.

Cheers

 

[E46Fanatic]

Yes for RWD, rears will wear out faster. In terms of how significant, I was suprised to read that a staggered setup where rear tyres are wider than fronts will reduce the difference btw fronts and rears. Basically the wider rears will see less heat generated under the same driving conditions, as the drive force is distributed over a larger contact patch compared to narrower tyres. Having said that, you are already on 28k kms and have 50% wear on a set and 20% on the other. I think thats pretty decent mileage for RFTs.

 

[astroboy]

I do not agree RWD is wearing rear tyres faster than front tyres. My other 2 RWD cars both giving a consistently higher front tyre wear than the rear. One is a 2.3L and the other 1.3L Both car, the front tyre wear is almost double as fast as the rear tyres.

.... unless u seldom use brake and seldom take corners la..

Now why front tyres wearing faster? That's due to cornering and braking, both actions are putting far more stress on the front tyres than the rear. While the accelerated rear tyre wear on a RWD can only be caused by 2 reasons: Frequent hard acceleration and mis-alignment.

Maybe a 50/50 balance weight chassis is balancing out the tyre wear between the front and rear but I have yet to experience that to qualify for a comment.

Mis-alignment can cause uniform wear on both side tyres and that's in a form of excessive toe-in with tyre looking like this from the top / \

When u drop the suspension, you should take a bench mark reading on the wheel setting from the degree of toe-in, caster, camber to alignment. After the drop, try to set it back to the OEM setting. Once your drop the car, your wheel alignment setting, camber and toe-in will deviate from stock settings. That might have caused the problem... unless you do a lot of donuts like our "Advance Driving Instructor" did to his E36 Coupe..

My rule of thumb is always keep the better tyres for the front for safety reason but GHS's case is unique la.. and of course, I'm talking about non-staggered setup la..

My comment is based on the normal RWD car with "neutral" gentle driving attitude la.. our balanced chassis and powerful engine might be very different la..

 

[ALBundy]

Astroboy, I find your case rather peculiar instead.

It doesn't matter how hard one accelerates in a RWD, the stress is always on the rear wheel tire since to move a car from stationary to X speed, there has to be some sort of acceleration, and hence more tire wear on the rear tires are inevitable (compared to the front wheels). And generally, the tire wear disparity between the front tires and rear tires is usually greater in a RWD vehicle, because whenever there is acceleration, the weight of the car shifts to the rear and the rear wheels do also provide the longitudinal force. In a FWD, when acceleration happens, the weight shifts to the rear but its the front tire thats providing the longitudinal force.

Try launching a FWD, in a carpark with some fine loose gravel and tell me which tire will wear off faster.

As for excess cornering being a cause of wearing out tires faster, I disagree with that as well. I assumed you are talking about wear on the outer part of the tires(well at least that's what I have experienced) when one corners at high speeds all the time.

All that needs to be done is to get some camber adjustment plates and set the front camber to 1.5 degrees. Stock is around 0.8 to 1 degree and is more suitable to daily non-aggressive driving. That will ensure even tire wear and still, your rear will wear out faster.:burnout:

Cheers:love:

p/s GHS, what I do now is to use a softer compound for my tire to lessen the disparity.

 

[MSport]

But since the UDM is nearly 50%-50% weighted, then why should the rear tyres wear out faster? Shouldn't all be wearing out together?

 

[initialM]

As for me the rear tyre wear out faster

 

[ALBundy]

But since the UDM is nearly 50%-50% weighted, then why should the rear tyres wear out faster? Shouldn't all be wearing out together?

You are talking about the weight distribution of the car.

I am talking about the forces acting on the car when its accelerating.

Dynamically, especially when its under acceleration, the there is more force on the rear tires than front, irrespective whether it has 50-50 weight distribution. Likewise when its uder de-acceleration, there will be more force acting on the front tires.

Cheers:top:

 

[loafer]

I believe the 50/50 weight distribution is there to ensure that the center of gravity is always close to the middle of the vehicle. It has nothing to do with your tyre wear

 

[GHS]

My rule of thumb is always keep the better tyres for the front for safety reason but GHS's case is unique la.. and of course, I'm talking about non-staggered setup la..

Yeah I know that's the conventional method - putting tyres with more thread at the front. But I recall reading from somewhere that for normal road-going drivers like me, it is safer to have the rear tyres with more thread, as:

more thread at the rear = more traction at the rear = less possibility of dealing with an oversteer situation which is harder to control.

So I Google-ed it up and voila, here's the link
http://paultan.org/archives/2007/10/20/changing-two-tyres-at-a-time-front-or-rear-axle/

Just wanted to see if anyone can attest to this?

Some quotes from the URL above:
"...But in reality, even if the front is more worn out than the rear, the correct thing to do is the put your less worn out rear tyres at the front axle and put new tyres at the rear axle..."

"...This is because when the front has more grip than the rear, the rear will lose traction before the front of the vehicle during a corner on a wet or slippery road. You will oversteer and fishtail because of hydroplaning. As you know, once the rear starts sliding its quite hard to recover unless you’re a very experienced driver. It’s also better for the driver who has been used to more grip at the rear than the front all this while before the tyre change to get used to the new grip levels if you put the new tyres at the rear..."

 

[David Yong]

Bro GHS, it's time to go for Advanced Driver Training

 

[astroboy]

Bro GHS, more tyre tread = less grip on tarmac road. Unless u r talking about off road where u need to thread to act like a claw.

On tarmac road, its about surface contact. More surface contact = more grip. Less thread tyres will provide more surface contact. Now u now why dry race tyres has smooth surface? The 4 groves on the F1 dry tyres are there to limit grip to slow down the F1 cars to make the race more competitive.

I'm surprised to see Paultan made those remarks..

 

[GHS]

Ah ic... my bad
I got tread and dry grip all mixed up...
I guess the tread/grooves are more relevant in wet weather for water dispersion, and Paul Tan was probably referring to that...

OK for discussion sake, referring to the few statements in the last few posts:
1) "More tyre tread = less grip on tarmac road";
AND "More surface contact = more grip"

Therefore it's good to have tyres with less tread on the front for better braking/cornering grip in the dry?

2) "...the correct thing to do is the put your less worn out rear tyres at the front axle and put new tyres at the rear axle..."

"...This is because when the front has more grip than the rear, the rear will lose traction before the front of the vehicle during a corner on a wet or slippery road..."

Putting tyres with more tread at the rear will help with wet grip on the rear and avoid a sliding tail in the wet?

So does this mean that somehow for everyday drivers, putting the newer tyres (read: more tread) at the rear is a "safer" option, since not everyone knows how to deal with oversteer?

Korek??
Hope I'm making sense here hehe...

 

[turbology]

1) "More tyre tread = less grip on tarmac road";
AND "More surface contact = more grip"
Therefore it's good to have tyres with less tread on the front for better braking/cornering grip in the dry?

"Grips" is determine by the contact surface friction of tires, and road surface. Few factors can affect grips, include contact patch (shape), surface area (cm square), tires compound, tires thread, and etc.

If every others factors are the SAME, then yes, more surface contact equal more grip.

2) "...the correct thing to do is the put your less worn out rear tyres at the front axle and put new tyres at the rear axle..."
"...This is because when the front has more grip than the rear, the rear will lose traction before the front of the vehicle during a corner on a wet or slippery road..."
Putting tyres with more tread at the rear will help with wet grip on the rear and avoid a sliding tail in the wet?

You can't just have more grip at rear but little at front. This will achieve high-understeer. Both front and rear grips are equally important regardless FWD, RWD, or AWD.
But for most drivers, during panic-ermergency situation, their first instinct is to step brake if anything happened. Thus, having understeer is a better "solution" for those drivers, which result "more grip is needed at the rear than front".
I for one prefer oversteer, because almost all pro-drivers will agree oversteer is easier to correct than understeer without losing much speed and time.

So does this mean that somehow for everyday drivers, putting the newer tyres (read: more tread) at the rear is a "safer" option, since not everyone knows how to deal with oversteer?

Yes.

 

[chaiks]

GHS,

Btw, just curious, did you follow BMW manual to pump more air in the rear tyres than the front? Or, you follow the group that pump even pressure all round?

cheers.

 

[turbology]

I believe the 50/50 weight distribution is there to ensure that the center of gravity is always close to the middle of the vehicle. It has nothing to do with your tyre wear

50/50 weight distribution is to ensure natural handling characteristic, and archieve balance oversteer/understeer of the car.

Center of gravity(Cg) is determine by the height/weight of the car.

For car with heavy front (example, Mitsubishi Evo for 60/40 front rear distribution), during a hard corder, the front outer tires will wear out faster.

 

[GHS]

GHS,

Btw, just curious, did you follow BMW manual to pump more air in the rear tyres than the front? Or, you follow the group that pump even pressure all round?

cheers.

I'm pumping 34 PSI all round (I'm on non-staggered 17" for the moment). Since BMW recommends it, any benefits of pumping more air into the rear tyres?