I know there are a million oil threads here, but let's face it, these turbo diesels hold a lot of oil, and oil changes are the number one maintenance issue to keep your engine running for freaking ever.

Having said that, I have been running Mobil 1 (incorrect weight) for 10 months without issue. I opted to buy what is availble in FL (Rotella Full Synthetic 5W40 for the correct type rated for my diesel). It instantly made my baby sound like a tractor or dump truck with heavy resonating in the cabin as soon as I crunked it up for the first time after the change.

I have suffered 4,000 miles, and finally decided to go back to Mobil 1. I found 5W40 synthetic at AutoCrib for $6 a quart.

Made the change, and my baby is back. Smooth and quiet, resonating gone, I am happy, but poor.

I know the smart guys here are going to say it shouldn't make it sound better, or feel smoother, and the cheap non-synthetic is good to go... I may try something else down the road when I am poor again, but my experiment proved my car needs Mobil 1 to make me happy.

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85 300CD Turbo "Das Polluter" 230K sold for $3,000

98 BMW 323is

It shouldn't make it sound better, or feel smoother, and the cheap non-synthetic is good to go........

How's that??

Actually, I prefer the synthetic.....but, you'll never make the case that Mobil-1 runs quieter than Rotella-syn. That's just the placebo affect.

I think its the placibo affect.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Our 300D has Rotella Syn 5w40 in it, and our two SD's have Mobil 1....they sound/run the same. The SD's will be transitioning to Rotella soon...it costs less. Mobil 1 is $6.19 a bottle, while rotella can be had for $18 a gallon in a big jug. Much better. Saves $1.70 per quart or $13.60 per oil change!

Both SD's have less than 1k till oil change time....so the transition will be within 3-4 weeks. We'll see if they sound or run any differently....I highly doubt it.

Our 300D went from Dino rotella 15w40 to 5w40 Syn Rotella and it did run smoother and starts WAY faster in the cold. With its new glowplugs/relay/oil you can glow 8 seconds and pretty much just "bump" the starter and its running! Even in real cold temps! It will start in 1-2 rotations even at 5F!

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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)

But I do have about 2000 miles on my recently changed Mobil "1" 5 40 and I think it is totally wonderful. Easy starts, smooth and quiet, fast warm ups on a cold engine, probably a little better fuel mileage. I did use a short quart in that time, mostly pretty fast driving, Indianapolis to DC over New Years.

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

[quote=Brian Carlton;1732082]It shouldn't make it sound better, or feel smoother, and the cheap non-synthetic is good to go........

How's that??


That is funny!!!

Let me live in my newly found bliss for a day already.....I may retract this post after I switch for cost reasons down the road....

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85 300CD Turbo "Das Polluter" 230K sold for $3,000

98 BMW 323is