a week ago, i picked up my 1997 c140[23,000 miles] from M-B Sugarland. while it was there it was put up on their alignment rack, shoes were rotated and balanced, and, according to the invoice, under starmark, both front lower control arms and bushings were replaced.

i picked up the car. not having my tire pressure gage with me, i did not check tire pressures before leaving the dealership. drove home. put the car up and went out of town.

today, returning from my business trip, i took out the beast. before i drove out of the garage, i checked tire pressures. sort of took me by surprise. LF, LR, RR indicated 32psi. RF indicated 35psi.

this car is generally driven with the trunk empty and only a driver on board. i would call this less than a normal load. and its driving speed will be less than 100mph. and the speeds will not be at any sustained levels for any more than 45 minutes.

for this set of conditions, M-B recommends an all-around pressure of 27psi.

can anyone tell me why the M-B dealer would decide to inflate its customers' tires to a higher than factory-recommended pressures?

at these higher pressures, would tread wear be accelerated?

if one were to go back to 27psi all-around as M-B recommends, what would happen to miles per gallon figures? for 4500 miles, tires were inflated to benz spec: mpg ranged from 16.4 - 18.5. for 400 miles at the benz dealer 32psi-35psi inflation level, mpg was 16.8.

all ears.

I've noticed that every shop I visit over-inflates tires. They usually go by what is printed on the sidewall of the tire, which is a big mistake. That number is strictly the maximum amount of pressure that tire will hold, and bears no relationship to what each car should ride on.

I also realize that the "pop-up" style pressure gauges that come attached to the tire hoses are wildly unreliable and inaccurate. I refuse to let any shop use one. My experience is that the tire pressure on my four tires have been as much as seven lbs off.

I always demand that they use my tire pressure gauge, which is a $50 round gauge with a hose and a "clamp-on" type nozzle end. It is usually used by racing mechanics, and it is very accurate.

I always was under the impression that running higher tire pressures would result in better fuel economy due to less rolling resistance, friction, etc....

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

i'm with you about gages. i use the gages that i used to use when i was flying my light twin.

i buy mine from sporty's, round with a 12 inch hose and a bleed valve. made by g.h. meiser and co. in posen, il.

labeled an accugage, website is www.accu-gage.com.

and the way i see it, overinflating the shoes leads to premature wear.

I got my gage from that website.

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

Just as Paul explains that the pressure marked on the tire is the MAXIMUM, the pressures inside the fuel flap are MINIMUM, not RECOMMENDED pressures.

We need to swap dealers because my dealer insists on inflating my tires to the fuel flap pressures which cause premature tire wear on my cars.

Have a great day,

My car always wears the shoulders of the tire way before the center tread with the fuel flap pressures. I usually use 35 psi on all corners for a more normal wear even though recommended is 28 front / 32 rear.

Make sure to observe the max pressure on the tires.

__________________
Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record

Again, the fuel flap pressures are MINIMUMS.

Have a great day,

i started this thread sort of as a method of "scoring" this new m-b dealership in sugarland, texas.

ordinarily, i wouldn't be taking any one of my benzes to a dealer. but this latest edition to the fleet was starmarked and i thought i had some starmark issues. oddly enough, the issues for which i took the car in were denied as "trim" items.

and though i had no handling or suspension-related issues, when i picked up the car lower control arms and bushings had been replaced for free.

because this dealer had a dedicated alignment bay, when i left them the car, i authorized an alignment, principally because i cannot prove from the po's service records and the starmark inspection docs[m-b san antonio] that the suspension has ever experienced an alignment. i thought it would be a good thing to have done.

now, here is a brief history of this c140. it was originally purchased by an elderly san antonio couple in december 1996. until march 2003, it traveled only 20,300 miles. car was equipped with virtually new michelin energy mxv4+.

driving the car back from san antonio to willis on a farm-to-market road, a came up on a pick-em up towing a combine. i came up on him at about 120 and was about to overtake him when something sharp fell off the trailer, missed it with the fronts, it holed the right rear.

tire was changed, but spare was not the same tire[it was an earlier version]. we thought that "holed" tire could be successfully repaired, and it was. but within six weeks, while parked, it decided to deflate.

since i hated the michelins, at 22557, they were replaced with dunlop sp sport a2's. when replaced, since i do a lot of terminal braking from high speeds, dirtying front alloys rapidly, dust shields were installed on front wheels.

at approximately 23,600 miles, mid-June, i watched a pick-up slowly collide with the rear end of this c140. then drive off before i could catch the guy. airbags did not deploy. a minor chip out of the plastic rear bumper and some "noticeable only to a perfectionist" misalignment of the rear bumper's top chrome overlay.

all the same, i felt that the virtually immaculate beast had been molested and i stopped driving it that day. it was stored in a climate controlled garage. it was taken out for a week-end in november for approximately 40 miles. it was taken out in early february for about 60 miles.

on 3 march, car was taken to m-b sugarland. at pick-up, on 5 march, mileage on the car as 23, 992.

as of today, 15 march, the odometer reads 24,700.

most of these recent miles have been high speed ones.

though i think that the dealer balanced and aligned without normalizing pressures, when i started this recent driving bout, i set cold pressures at 31psi all around.

my indy and i noted the tire conditions on the virtually brand new dunlops before i took this car to the m-b sugarland dealership. there were no noticeable wear abnormalities. today, we examined the tires again after these 700 miles. distinct evidence of outside edge "feathering".

my indy looks at this and says that the "toe-in" appears to have been set improperly when it was at the m-b dealer being "aligned".

sound correct to you suspension gurus out there?

the other funny thing is my dust shields. when m-b sugarland got the car, both shields had ventilating slots. when we were inspecting the tire wear today, we noticed that now only the RF shield appears to have ventilating slots. now the LF shield may still have them, but the m-b sugarland alignment tech failed to position them so that they were exposed to the apertures in the oem alloys.

tomorrow, i shall know more. it would really be interesting if the LF shield was from another car.

lastly, i am keen to see the undercarriage of this car. running at about 105 this weekend, i heard a "thud" underneath the car. i saw nothing on the road. i saw nothing on the road behind me after i heard the thud.

car doesn't seem to handle any differently. but, could it have lost one of those recently starmark-replaced suspension components?

all ears.

i started this thread sort of as a method of "scoring" this new m-b dealership in sugarland, texas.

ordinarily, i wouldn't be taking any one of my benzes to a dealer. but this latest edition to the fleet was starmarked and i thought i had some starmark issues. oddly enough, the issues for which i took the car in were denied as "trim" items.

and though i had no handling or suspension-related issues, when i picked up the car lower control arms and bushings had been replaced for free.

because this dealer had a dedicated alignment bay, when i left them the car, i authorized an alignment, principally because i cannot prove from the po's service records and the starmark inspection docs[m-b san antonio] that the suspension has ever experienced an alignment. i thought it would be a good thing to have done.

now, here is a brief history of this c140. it was originally purchased by an elderly san antonio couple in december 1996. until march 2003, it traveled only 20,300 miles. car was equipped with virtually new michelin energy mxv4+.

driving the car back from san antonio to willis on a farm-to-market road, a came up on a pick-em up towing a combine. i came up on him at about 120 and was about to overtake him when something sharp fell off the trailer, missed it with the fronts, it holed the right rear.

tire was changed, but spare was not the same tire[it was an earlier version]. we thought that "holed" tire could be successfully repaired, and it was. but within six weeks, while parked, it decided to deflate.

since i hated the michelins, at 22557, they were replaced with dunlop sp sport a2's. when replaced, since i do a lot of terminal braking from high speeds, dirtying front alloys rapidly, dust shields were installed on front wheels.

at approximately 23,600 miles, mid-June, i watched a pick-up slowly collide with the rear end of this c140. then drive off before i could catch the guy. airbags did not deploy. a minor chip out of the plastic rear bumper and some "noticeable only to a perfectionist" misalignment of the rear bumper's top chrome overlay.

all the same, i felt that the virtually immaculate beast had been molested and i stopped driving it that day. it was stored in a climate controlled garage. it was taken out for a week-end in november for approximately 40 miles. it was taken out in early february for about 60 miles.

on 3 march, car was taken to m-b sugarland. at pick-up, on 5 march, mileage on the car as 23, 992.

as of today, 15 march, the odometer reads 24,700.

most of these recent miles have been high speed ones.

though i think that the dealer balanced and aligned without normalizing pressures, when i started this recent driving bout, i set cold pressures at 31psi all around.

my indy and i noted the tire conditions on the virtually brand new dunlops before i took this car to the m-b sugarland dealership. there were no noticeable wear abnormalities. today, we examined the tires again after these 700 miles. distinct evidence of outside edge "feathering".

my indy looks at this and says that the "toe-in" appears to have been set improperly when it was at the m-b dealer being "aligned".

sound correct to you suspension gurus out there?

the other funny thing is my dust shields. when m-b sugarland got the car, both shields had ventilating slots. when we were inspecting the tire wear today, we noticed that now only the RF shield appears to have ventilating slots. now the LF shield may still have them, but the m-b sugarland alignment tech failed to position them so that they were exposed to the apertures in the oem alloys.

tomorrow, i shall know more. it would really be interesting if the LF shield was from another car.

lastly, i am keen to see the undercarriage of this car. running at about 105 this weekend, i heard a "thud" underneath the car. i saw nothing on the road. i saw nothing on the road behind me after i heard the thud.

car doesn't seem to handle any differently. but, could it have lost one of those recently starmark-replaced suspension components?

all ears.

Where do you live that you drive over a 100mph?

metro houston.

has this remarkable toll road. i call it the rent-a-bahn.

and then there are the back roads. some of them quite good and virtually empty.