How come Mercedes don't rust?

My 83 240D has very little or no rust.Why? I'm not a metallurgist but I'm thinking, 3 ways you prevent rust is to minimize seams/seam welds, because rust tends to aggregate their; another is through paint and coating; the third is type of steel. Every other car from this area has rust on it, even expensive foreign cars. The only exceptions are Ford's LTD.

Hi.
I purchased my 77 350slc from near SAS
in NC..
It had very little rust.. only in parts where water was accumulating.
I guess the fact that MBs don't rust as much is a combination of the paint primers used, the thickness of the sheet metal,
and other factors..

The metal used in the MBs (at least the older ones), seems to be thicker than the paper thin sheet metal used in newer cars..

There is nothing like the vault-like sound when i close the doors in my car!

My brother is currently working on an '84 230CE that has some nasty and difficult to repair rust areas eg lower corner of the rear screen, rear wheelarch lips and rear of front wing. My '87 190E however has hardly any body rust. It seems to me (from observation) that metallic-painted cars are more rust-prone than plain colours. But thickness and quality of steel are more significant, as an '86 Citroen 2CV I'm renovating can demonstrate!

[Aaron]

Don't let me dampen your spirits gentlemen, but Mercedes DO indeed rust--at least in Ohio they do! Sure, you won't find a rusty 124, 126 or 201 yet, but I've seen a few that are getting kinda scary. The processes for undercoating have improved trmemndously since the early days and the primering/painting steps also have a large effect on the durability of the sheetmetal. IMHO, the W116s were the worst ones to rust, even more so than the 108s and 109s. I've seen plenty of daily driver 113 SLs and have had one begin to buckle in while I had it up on the lift at the shop. You must also remember that the better an owner protects their car from the ravages of the road, the longer it will last. Matter of fact, I had a '75 450SL in today with 283,000 miles on it and the rockers were still nice and solid (I was dumbfounded!) whereas the rockers on my '80 300SD (W116) with only 189,000 miles on it are almost totally gone. So it's a variety of factors, but believe me, Mercedes cetainly do rust, and as for the really old ones, I've seen lots of 190SLs which had rusted badly because Mercedes used cheap East German sheetmetal. Anyhow, nothing's impervious to the tin worm--even Mercedes. Hell, the DeLorean automobile even uses a mild epoxy coated steel frame which, if the coating cracks, lets moisture in and can get extremely dangerous. I've seen DeLorean mechanics jam a pen right through a frame rail. Yikes!


------------------
Rgds,
Aaron Greenberg
MB technician
Mercedes-Benz of Cincinnati
'67 250SE Cabriolet
'77 450SL
'80 300SD
'85 380SE
'86 420SEL
'89 420SEL
'93 300E 2.8
'74 Jensen Interceptor Mk.III
'81 DeLorean DMC12
'84 BMW 745i Turbo