Thinking of switching to synthetic oil today to help keep the motor cooler in the desert climate this summer. I travel around 300 miles / day at 100 to 115 F* pushing around 3,200 rpm (long highway miles) for hours

Original SDL 603 motor with 351,xxx miles. Oil changed at approx 3k intervals for life.

I've heard that due to the synthetics cleaning (de-sludge) capability it is better to start with a 50% dino & 50% syn blend as to not break up too much crud that may lodge some where i.e. oil passage.

So any thoughts or experiences I might want to know?

Thanks

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1986 300SDL 440,xxx

I went from dino to straight synthetic on both of my 200k+ mile 95 E300's without any issues.

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Jim

It depends on previous service. If the oil has been changed on a regular basic of say every 3 to 6k with filter and good quality oil, then change to syn at next service. If oil is never changed just refilled when low, then don't change to syn at all. I think you get the idea. When I got my old 500SEL, I changed the oil when ever it got black. When I could check in the valve cover and it was clean, then I went to syn and have not looked back.
The 300D, I changed as soon as I got it at 290K miles. No leaks. No usage.

I hope this has helped in some way.

Paul
















i

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84 500 SEL (307,xxx miles)

Just switch it and ride! Maybe do the first oil change at your normal 3-5k, and then you can get at least 8k out of it. I have been running 8-10k intervals and she is purring.

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1987 300TDT - 195,000 (Original #14 head)
1993 190E 2.3 - 105,000
1981 300D - 250,000

Very interestig thread! I was under the impression that it was reccomended not tk switch over older vehicles to synthetic...

If your car has leaks on regular oil, they may only be minor or nearly non-existent. But once you run a thinner oil which has detergents and is cleaner, it may reveal the already pending leaks. If you have failing gaskets and seals, synthetic oil will make its way out of them easier. The oil however did not cause the leak.

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1987 300TDT - 195,000 (Original #14 head)
1993 190E 2.3 - 105,000
1981 300D - 250,000

Thank you boys!

Oil has been changed at about 3,000 miles for the last 26 years...and there are a few minute leaks so if they leak more it's time to fix them.

So I'll switch today & hope the new stuff will help the old boy keep running for many more miles...

Wowa...for got something...do all you synthetic users still change the filters at 3,000 miles or so. I forgot about the soot build up factor!

thanks all!

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1986 300SDL 440,xxx

... FACTORY recommendation on the 603 was 7500 miles between oil and filter changes...

you've been doing 3K the entire life of the car?

wow.

change to syn.
change the filter/oil every 10K and don't look back.

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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!

I had no idea.....the car actually sounds better (quieter) when I cange it at 3,000 but I guess I was just burning not only soot but loot.

Thanks again boys....great to have this group to steer through the fear of a little change

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1986 300SDL 440,xxx

^x2

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Jim

I changed the 80 240D to synthetic at 321K. had no previous service records from the previous owner, they Gave us the car with 305,906K.

Iam using 15/40w oil, didn`t leak before the change, and still no leaks.
Did the first oil change at 10K and filter at 5K. Oil usage hasn`t changed, about a qt every 12 to 1400 miles.


Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

is it burning or leaking? on a 3K oci, that's 2 quarts replaced... I'd worry about more than 1 quart in an oci... 1/2 would bother me.

__________________
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!

Really? Not 5,000?

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14 E250 Bluetec "Sinclair", Palladium Silver on Black, 153k miles
06 E320 CDI "Rutherford", Black on Tan, 171k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver, 142k mi, wastegate conversion

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Last night we rolled 337,000 miles. You think this is an excessive amount of oil useage with these miles?

No oil leakage, well........ maybe a drop now and then. engine is dry on the bottom side as well and the bottom side of the car.

Oil level stays about the same with around town driving and some freeway driving. It`s when taking a long trip and hours of pounding down the Highway it tends to use some oil, not any more than when using Dino oil.

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

get ready for the oil leaks......