remember some time back that on the npr 'car talk' radio hour, click and clack said that with some caveats, one does not have to change engine oil on a time basis. the caveat, a bunch of cold stars and a mile here and a mile there. looked through the maintenance records on one of my 126's. 1000 miles. oil changed last in august 04. mobil 1 15w-50. i drive this car maybe once or twice a month. never less than 20 miles or so. am i screwing up? i am doing this same thing with my other 126, a 6 cylinder unlike the car mentioned above. and my 91 miata with something less than 45k miles.

Janko....I think you would be throughing good money away doing premature oil changes. All Modern automotive oils are made to go the distance. They are not going to break down just sitting in a car that occassionally is used.
I have always done 5,000mi. oil changes no matter the amount of time elapsed or whether it was dino oil or synthetic......( i drive mostly HWY)

Some say I am throughing money away when I change synthetic at 5,000mi...because the oil manufacture says it s good for 10,000 or 15,000mi.
The real problem is the oil filters clog before the oil would ever begin to break down.. then you have dirty/ contaminated oil circulating for another 10K...which is definitely not good!

I would be more concerned with some funk growing in the old diesel fuel sitting in your tank...

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FRED

Daily Driver: 98 E300TD 199K
Hobby Car: 69 Austin Mini
Past Diesels: 84 300SD, 312K
87 300SDL, 251K
94 Chev. K-1500 6.5Ltr.TD, 373K

One thing to consider is with short trips/extended sitting, it is possible to get moisture in the oil if it does sit for a LONG period of time.

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91 350SD
14 F150 Eco
19 Fusion Hybrid
11 GT500

You know I used to worry about that too....but condensation could occur on fresh oil or old oil if sits long enough and the conditions are right. The good thing is water and oil don't mix.... Once the engine is started and the engine gets to operating temp. the water vapor is moved out through the crancase vent and exhaust.. The only preventative measure is to start the engine occassionally even if its in storage.

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FRED

Daily Driver: 98 E300TD 199K
Hobby Car: 69 Austin Mini
Past Diesels: 84 300SD, 312K
87 300SDL, 251K
94 Chev. K-1500 6.5Ltr.TD, 373K

starting gets oil into all the nooks and crannies, but you would have to idle the car for 20 or more minutes to get up to operating temp to boil off the water condensation. something the Owners manual SPECIFICALLY states NOT to do!
a better plan is to start and drive on highway for 10 miles or so to get a load on the oil and heat it up well. to get it out.
the worst thing about water vapor is when mixed with old oil, it makes a mild acid that can ruin the surface of all the parts of the engine... pitting is bad.
I would drive a parked car with used oil for 20 minutes or so, at least once a week. or park it with FRESH clean oil. and not drive it at all... not sure which is best though.
John

Oil should be changed at least once a year. MB specs 13k miles or one year changes. So MB doing millions in R&D over the last century have determined that with Mobil 1 fully synthetic you need to change the oil once a year regardless of mileage.

I change my oil twice a year regardless of mileage.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

uh oh, blueranger will be on here any min. trying to say that 20k is ok to run

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have no worries.....President Obama swears "If you like your gun, you can keep it

uhh oh another oil thread!

5000 synthetic, 3000 dino on mine. Time is never a factor due to the amount of miles I drive, (about 14,000 a year equals change every few months)

(synthetic all winter, dino rest of the year.)

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Adam Lumsden
(83) 300D
Vice-President of the MBCA International Stars Section

Not to mention he'll probably tell us after the 20k oil change, that it's ok to pour 20 gallons of unfiltered motor oil in the fuel tank.

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'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.

Change mine every 3 months on all my vehicles. Added expense yes, but good piece of mind. This coming from a life long mechanic who has worked on thousands of vehicles. Sure, most vehicles can run 5000 or more on synthetic, but my gas vehicles insides and oil looks like new when changed and a diesel puts much more trash into the oil. I would rather spend the extra money (which I can afford), than take even the slightest chance on my engines.

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85 300CD
83 300TD
78 240D (daughter)

5000mi here on the Benz's, the others receive stuff usually every six months as they're not driven much.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]