I changed oil on my car with Rotella W15-40. I'm just about 1/2 quart short, and I happen to have some generic W20-50 around. Any danger of putting that stuff in?

jeff 1991 300d, 131k

don't put it in unless it is diesel rated oil.

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

Danger? Not really. There is also no danger in running 1/2 quart low, fill it when you buy more oil.

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Gone to the dark side

- Jeff

I doubt if 1/2 quart would make any difference. But, I do not think it is a good idea to mix any of the multiviscosity oils especially if they are different viscosities.

I do not think it is a good idea to mix different companies multiviscousity oils that even if they are the same viscosity either. As, I believe the different companies may use different set of chemicals to achieve their pour points.

But, I am cautious because do not have enough knowledge about it.

In fact out here in S. CA I use single viscosity oil. There is no problem caused by pouring 20wt into 30wt except that it is no longer 30wt; you end up with something thinner and in between.

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84 300D, 82 Volvo 244Gl Diesel

There's no real danger, but it's preferable to top off with the oil that you already have in there. That way you don't start affecting the oil's properties.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL

I'd drive it as is to the store and get another gallon.

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

Don't even bother with a 1/2 quart. The engines usually run better and consume/leak less oil when its about half way between the two dipstick marks.

I probably would be shouted at for writing this. I think people are paranoid. I mix it all the time, w10-30, w5-40 etc to my gas cars and diesel cars and it never gives me problem. If the car is a precision instrument like a watch then I probably would not do it. But MBZ engine is built tough and can take abuse within reasons. It may shorten the engine life by 1k miles out of 500K, I would still be very happy with 499K.

One thing I never short changed myself is the interval. I always change the oil between 3k-4k miles.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

Just a warning: Richard Pryor did it and he caught on fire!

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99 ML320
94 SL600
92 SL500
95 E320 Cabriolet
87 560SEC
86 300SDL Grease Car
80 380SLC Euro

13 Fiat Abarth
02 Maserati Spyder Cambiocorsa
00 BMW Z3
90 Rolls Royce Silver Spur
80 Ferrari 308 GTSI
88 Jaguar XJS12 H&E Edition
99 Land Rover Discovery

No danger. But don't bother if you're 1/2 a quart down. Wait until you can use the whole quart, then you won't have to find another way to get rid of it. As someone else said, make sure it has a diesel rating... it should say something like SF/CD (I don't remember what the letters are up to anymore...) the Sx/Cx means S for spark ignition engines, C for compression ignition (diesel). The x part is the specific specification, they keep getting higher and higher as engine technology demands more of the oil. Some oils are only Sx rated, these should be avoided in a diesel. Although even then, one quart out of seven probably won't hurt, especially if you are coming up on an oil change soon. Then again, running one quart low out of seven won't hurt anything either.

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1987 W201 190D

The additives in different oils will interfere with each other. There is no danger to the engine, but just dont do it unless you really have to.

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1984 Euro 300SDC, (4spd standard)
1986 Toyota Landcruiser Diesel HJ60 5spd X2

Gone but not forgotten (some sold, some stripped)
1983 300 SD, 1985 300 SD, 1983 240D, 1986 300 SDL, 1985 300 SDL, 1983 300 D, 1984 300 D, 1985 300SD, 1987 300 SDL, 1983 300 SD, 1985 300 TD Euro, 1983 380SEC, 1990 300 D, 1987 300D, 1982 300D, 1982 300D, 1994 E420, 1987 300 TD, 1987 300 D, 1984 300 D

I do not believe this to be true. Do you have any further information on this?

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1987 W201 190D

Yeah, that's what I was thinking. The car will probably never know the difference. It's only 1/2 quart out of 7 quarts, that's 1/14 of the total. Not going to ruin the entire engine for a few thousand miles of oil.

Thanks,

jeff

It goes along the same lines as "pick one oil and stick with it."

Mixing won't kill the engine but its not good for it.

All I can say is....I wouldn't do it. Spare oil laying around can always be used in the lawnmower! I think I've used 3-4 different weights and types in our 5.5 briggs mower. Currently its using a leftover quart of M1 Turbo diesel and truck...seems to like it! Next up is some 5w30 castrol synthetic....

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)