I came across two completely different opinions about which viscosity oil to use in the winter for a high mileage diesel with some cold starting issues. Some say thicker oil (15W-40) is better for some reasons, others say thinner oil (5w-30) is better for other reasons. What's your opinion and is it based on experience?

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'99 S420, 155k
'91 VW Vanagon GL, 150k
'85 VW Vanagon GL, 120k
'82 VW Westy, aircooled, 165k

Good lord, will it ever end?

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-justin

1987 300TD, 1987 300TD
2008 R32, 2000 Passat Wagon

obviously not. not just yet. lol

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1980 300D

This is old hat, just like in a gasser.

The more wear observed, the thicker the oil should be. Thin oil slips past worn areas like rings, increasing consumption. You can also hear more knocking when a thinner oil is used on engines reaching end of life, of have been poorly maintained.

Also you need to use the weight oil as found in the FSM based on climate and driving habits.

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

0w40 running in my dad's 300SD right now, and its nearing 282k! No knocking and it can practically start without glowplugs at 5F the compression is so good. I have 5w40 in mine and it loves it, runs incredibly smooth. When the '83 is due for its next change in about 2k, it will be switched to 5w40.

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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)

0w40 is not heavy enough neither is 5w30 (is it even diesel rated?). 5W40 Synth seems to be the drug of choice.

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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

They're both diesel rated (especially the 5w40, its called turbo diesel synthetic) and both approved by MB, so I am guessing they're fine. I am going 6k on my current oil because I will be going on a trip, and I am sending in a sample of the 6,000ish miles oil to see what they say. Should be interesting.

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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)

My 300SDL, per maintenance records, has received 10W30 and 5W30 oil changes up until 225K miles from the new car dealer. And there is not a better running 300SDL in the world.

0W-40, 5W-40 and 15W-40 are all 40 weight (most between 14 and 15.5 cSt) at operating temperature. All three are way too thick for optimal lubrication at any temperature below 50C..only the 0W and 5W persuasions are too thick to a lesser degree than the 15W.

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2009 VW TDI Jetta Sportwagon 172k miles (rear-ended harder than Elton John on 8/4/13. Total loss)

1991 Volvo 240 142k miles (T-boned by a stop sign runner. Total loss)

10W 30 was in the car when I got it, I kept it up until I got more used to the car, and it always burned quite a bit of oil, since I bumped to 5W40, I have not lost a drop. that says it all for me.
John

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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!

Check your owners manual, I believe xW30 is only OK up to about 70 F ambient in a 617. 15W40 is probably OK for just about any moderate temperature, but it's not going crank very fast or have good initial lubrication in very cold temperatures. I use synthetic 5W40 year around.

I don't think there is any brand of 5W-30 oil that's diesel rated. There are some 5W-40 synthetic oils.

Just run 5w40 Delvac 1 or Rotella 5w40 and be done with it! Both have the latest and greatest diesel ratings. CHI or CHJ I forget.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Amsoil has a diesel rated 5w30.

"Series 3000 Synthetic 5W-30 Heavy-Duty Diesel Oil"
https://www.amsoil.com/storefront/hdd.aspx

but from looking at the specs, its actually closer to a 40weight

Same goes for ELF 0w30.
http://www.worldimpex.com/parts/elf-elf-excellium-full-tech-0w30-1l-bottle_557388.html

After i use up the amsoil and mobil in my cars ill probably switch them both to the Elf 0w30.

And no it wont cost me $11/quart! i get a discount at work

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Current:
05 E320 CDI
07 GL320 CDI
08 Sprinter
05 Dodge Cummins
01 Dodge Cummins

Previous
2004 E55 AMG
2002 C32 AMG (#2)
1995 E300
1978 300D
1987 300D
2002 C32 AMG(blown motor :[
1981 300SD
1983 300SD
1987 300SDL
2002 Jetta TDI
1996 S420
1995 S500
1993 190E 2.6
1992 190E 2.3
1985 190E 2.3 5-Speed

An oil thread?!

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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]