do you follow the specs on the manual?

i have always use 32psi all around. i wonder if i am missing something

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Ben
1987 190d 2.5Turbo

The door tag says to runn the fronts 6lbs less than the rears, IIRC, atleast on the 123s. So I keep mine up toward the max psi stated on the tires, but keep the fronts a little lower than the rear.

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I would be willing to bet that the "door tag" is a lot more specific than that. Some W123's specify 28 psi front, 32 psi rear.

In about 800,000 miles of 123 cars and about half that in other 124's and 210's I found 32 front and 35 rear to work very well. The extra few pounds in the rear prevented uneven and acclerated tire wear, especially the right rear.

Hope this helps.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

The guy who does my alignment recommends pressures between 32 and 35 psi. He says the Mecedes-recommended pressures down around 28 psi make a softer ride for the old farts (like me!) who buy Mercedes but it's not good for the tires.

Jeremy

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Yes, if you run 28PSI you will be looking at frequent tire replacement.

Get Buster to help you with those tire replacements. He looks like an ambitious sort.

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2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

You guys are gonna laugh, but I have too many cars to remember what goes in what (7) So I put 35psi in everything I own.

... if 40 looks bad, I let a little out...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

33/34psi all around on 300D w123 and 190E

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http://farm8.staticflickr.com/7271/7...144c3fc1dc.jpg

35 front, 40 rear. More if I have a heavy load, they're rated to 51psi.

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

Over here the automatic inflators at the gas stations have a default setting of 32psi.
It would be fair to say that 95% of the cars over here run 32psi.

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Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

Tire pressure requirement is set both by tire construction and driving style. Setting it per the tag inside the door is OK for starters but here is how I "fine tune" (learned this from my earlier SCCA days). Once set to tag recommendation, take a piece of chalk and put a line perpindicular across tread and down about an inch on the sidewall. Go out and drive in your normal manner. When you return, check the chalk line and see how much is scrubbed off. The ideal pattern should show chalk gone from tread area and just onto the area the tread begins to wrap down to the sidewall. If you are down on the sidewall, add air; if you only scrubbed from the flat zone of the tread, let out some air.
Why would a tire require more or less air than the manufacturer's recommendation? Tire sidewall stiffness is a key factor and is set by tire construction.

Benzman53, thanks! Your SCCA method sounds logical, and I will try it soon.