Poor front tyre wear on C270Cdi

[Geoff A]

Noticed I'm getting poor tyre wear on the outer and inner shoulders on both front tyres (Contis on my '05, C270CDi A/Garde estate). Classic symptoms tell me its under-inflation, but checking and double checking my pressures tells me I'm at manufacturers recommendations Anyone had similar? Should I be running 3/4/5psi or more higher to compensate for the heavy five-pot diesel in the nose? Any advice greatly received, ta

 

[wemorgan]

Did you check the pressures when the tyre was cold in the morning?

The recommended pressures should be the ones suitable for your car engine and tyre size. Usually there is a sticker in the fuel filler cap or driver's side B-pillar.

If that fails, then I'd get a full suspension geometry check at a place like:
http://www.mbclub.co.uk/forums/memb...-inmotion-geometry-alignment-calibration.html

 

[Geoff A]

Yes, tyres always checked when cold. Pressures are as recommended, and as shown in my fuel flap. Don't believe it's geometry, simply because of the evenness of the wear on both front tyres' inner and outer edges. She's good on fuel too, getting 48-50mpg, which I wouldn't get with scrubbing front tyres - it just looks like wear from under-inflation, even though its not. Geo-check could be worth exploring though, so thanks for that. If anyone knows differently, I'd like to hear more

 

[wemorgan]

There's an interesting thread here that I'm sure you've read:
http://www.mbclub.co.uk/forums/wheels-tyres/74013-correct-tyre-pressures.html

How many people are typically in the car?
How fast do you typically drive?

Like you suggest, it could simply be that your tyres are under inflated for your driving conditions.

 

[Geoff A]

Thanks for that thread, Will, and yes, I'm beginning to think its under-inflation for my conditions. Usually just me in the car for most of my 20k business miles and I'm not fast or mean on cornering, as I have a TVR to fulfill that need! Benz is just a motorway cruiser - and a very good one at that too.
Interestingly, just got off the phone to Wheels in Motion guys who suggest that the smooth wear on both inner and outer edges of both front tyres is a characteristic of under-inflation and not geometry. Going to try running a few psi higher than book values, to see how it shapes up - too much air though, will result in wear throughout the centre of the tyre. It'll be trial and error, I think.
Appreciate your help, and the pointers.
Geoff.

 

[prc]

I run +4psi on both 220cdi which seems to help, but not fully cure problem. I now get a bit more wear on outer 1/4 of tyre. Centre is 1.8mm, inner 1.6mm and outer around 1.0mm...

 

[robert.saunders]

Should I be running 3/4/5psi or more higher to compensate for the heavy five-pot diesel in the nose? Any advice greatly received, ta

are the wheels standard size OEM?

 

[ddentrec]

Hello,

I have a 2003 C180K estate. Has had 4 complete sets of tyres (Conti Sport contacts) in 60K motorway miles: has had 4 wheel alignment by MB dealer, pressures checked, and the car is driven sensibly and with no towbar.

Car had new front & rear suspension at 20K miles (it collapsed under warranty - new bushes, wishbones, springs).

But still it eats tyres - though all 4 wear evenly.

 

[prc]

Hello,

I have a 2003 C180K estate. Has had 4 complete sets of tyres (Conti Sport contacts) in 60K motorway miles: has had 4 wheel alignment by MB dealer, pressures checked, and the car is driven sensibly and with no towbar.

Car had new front & rear suspension at 20K miles (it collapsed under warranty - new bushes, wishbones, springs).

But still it eats tyres - though all 4 wear evenly.

Conti's are excellent tyres but IMHO wear real quick. When on the SC3 would need to swap 2 (rears) every A-service and then swap all 4 every B-service. The Goodyear GSD3 have made it through almost an A-service and almost at B-service (but admit they are no longer at the legal limits..)

 

[hygt2]

I guess you could run your tyre pressure heavy load at the front, normal at the back and see how it goes.

I rotate the tyres front and back every 6,000 miles because the whole set only last me about 12,000 to 13,000 with rotation and the tyre is Michelin Primacy HP MO-spec.

I just cannot imagine if Conti SC/PC, P7 or Goodyear GSD to last even 10,000 miles. I cannot stand having to get a new set of tyres more often than the service interval on the car.

 

[prc]

OK, maybe I should explain better:

A-service 2 rear tyres +-28000km
B-Service all tyres +- 56000km

I do get about 28Kkm between services, so fronts would actually do close to 56kKm. Tyre swaps for me also depend on time of year. During summer when it doesn't rain I will let them go to or past legal limit (as is the case now). Other times when it tends to be wet, I will swap at about 3mm.

 

[whitenemesis]

I have the same model as you, mine has the 17" wheels.

I run 33psi front and 37psi rear. I have always had Michelins and always had even wear across the width of both front and rear tyres. Approx. 18k miles from a set

Are you sure your pressure gauge is accurate?

 

[alexander patie]

as a workshop foreman working with mercedes for 14 years i have a little knowledge to share here.

ALL mercedes rear wheel drive cars will wear the rear tyres down the middle, and the fronts down both shoulders - if the alignment is correct. the best thing to do is to swap the wheels front and rear half way through their life if possible.

sadly of course this is not possible with cars with larger rear tyre sizes!

 

[Geoff A]

Thanks everyone for your comments - Alex sums it up nicely, which was how my W210 E-class used to wear its tyres a few years back (rears took the middle, fronts took the shoulders - which suggests playing with pressures to even this out a bit). Can't swap from fronts to rears, as they're different sizes, though alloys are OEM 17in five-spokes for the model of car. Will experiment with pressures and see how the wear goes and maybe change make when its time to replace rubber. Guess it's just a Merc thing!! Will post some pix when I get my ducks in a row.
Though I will get my gauge checked too.

 

[timskemp]

Anyone got any corner weight scales for a future GTG so we can all work out our ideal tyre pressures? My tyres wear the same - edges on the front, centres on the rear...

 

[Robbruce]

Hi Geoff, You say your getting 48-50mpg is this on a run or after reset on the computer because i have the same car on a 02 plate and i am only getting 33-35mpg

Thanks
Rob

 

[Geoff A]

Hi Rob, yes, on a motorway run it's pushing high 40s if I keep my cruising speed to around 80-85mph. Even bobbing around town, it never drops below 41-43mpg. I think I've got a good 'un. It rolls very freely - no bake or transmission drag.
Never trust computer, I always do a check each time I fill up my tank so I know how far I've travelled and how much fuel it's burnt.
Geoff

 

[Rory]

as a workshop foreman working with mercedes for 14 years i have a little knowledge to share here.

ALL mercedes rear wheel drive cars will wear the rear tyres down the middle, and the fronts down both shoulders - if the alignment is correct.

I've always understood this to be the case and my car certainly does this.

Yet the post above yours (from whitenemesis) says his tyres, both front and rear, wear evenly.

I've been running mine with fronts +2 and rears -2 of the minimum pressures, and that seems to make a bit of difference, but I've been doing many miles recently so can't be sure.

I must get hold of come chalk and try the chalk line test - you're supposed to be able to set pressures by adjusting them until a chalk line across the tyre wears off evenly. No idea if that really works though!

 

[AllanE]

You could try contacting Continental for advice on pressures - they may recommend something slightly different to the 'generic' pressures under the fuel flap.
You'd expect them to come up with something to justify 'uneven' wear!

There's an outside possibility it's down to your driving - say if you do a lot of maneouvering, the castor will roll the tyres from one camber to another which would then wear the inside and outside edges more...!