ok, I just changed my oil and put in 5w40 rotella T synthetic in anticipation of the coming winter. However, we still probably have a 70 degree day here and there, and the overall avg temp is in the 50's and 60's.

The question is NOT whether synthetic is better than dino, whether rotella is a true synthetic, whether my car is going to spring leaks and start shooting oil out of the windshield washer spouts, or whether I am going to suffer in eternity for using cheap oil.

The question IS, is this oil going to be too thin for the remaining mild days before it really hits?

Please, this is not an oil thread.

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The oil will not be too thin. A 5W-40 will protect just the same as a 15W-40 will in mild temps.

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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.

I haven't run synthetics in my diesel yet. I plan to. The Rotella 5w-40 was one of them I was looking at. I have run synthetics in gassers since the late 80's. I do trust synthetics. I doubt you will have any problems. Oil has come a long way in even the past 10 years. Not to mention in the past 25-30 years.
Tom

ChetWesly....you'll be fine. Thats why it has the "40" weight rating to keep you covered in warm/hot temps as well as the "5" for cold temps and start-up. Its a good quality diesel rated oil..... thats what matters and not whether it is a "true synthetic" (thats not worth the brain power expended debating).

I personally like blending RotellaT 5W40 with Rotella 15W40 for winter and then do more frequent oil changes than you would do with a full synthetic.
It is your personal preference........

Cheers

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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

I don't know much about oil or what the numbers really mean. I could learn myself on that a little more I guess.

Thanks for the responses.

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I just switched our 300D over from 15w40 dino rotella to the 5w40 synthetic rotella yesterday. Runs great on it. I think I may use it in my car too...(as will my dad)....its almost $2 a quart cheaper than Mobil 1. And it comes in gallon jugs (easier to fill the engine! ) I have 4500 miles to go till my next change though....

I figure that its better to do the changes a little more often (maybe 4000-4500 miles) on Rotella synthetic....than to go longer on Mobil 1. I also found the Turkish Made Fram Filters at Pep Boys!! I bought all 4 they had....and will be going back soon to see if they have more. Gotta stock up.

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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)

I've been running Rotella T Synthetic 5w40 year-round. No problems.

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83 300d - 390k

I use rotella or mobil 1 5W40 year around, including some 100F+ ambient temperatures. It will be fine.

I run Mobil Delvac 1 5w40 year round. Have for the past four years.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

your not going to spring leaks... if anything it will clean everything out and renew the seals.

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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

No, it's not a true synthetic oil. It's traditional oil thats been cracked to give it similar properties of synthetic. Search google for "group III oil".

Cervan is right. You won't spring leaks, it will probably even help if you have any seeping seals.

Fingers crossed on that promise

Don't forget the fact that these synthetic products have powerful detergent characteristics and can un-do years of mis-deeds (running petro-based oil).

On the plus side, they can free up piston ring deposits with extended use, restoring compression, lowering fuel and oil consumption, and make an old engine run at its best. I know a few folks (W123 and W126 hi-milers) who have switched to these modern oils and have had mostly positive experiences.

It also eliminates this "seasonal oil changeover" mindset and permits extended drain intervals when monitored via UOA. In many cases, operating expenses can be reduced at several levels.

Enjoy

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1998 W210 diesel (wiped out by a texter)
Baum spring compressor "for rent"

Compared with dino oil (I'm running Rotella 15W40 in my 240D) has anyone seen a noticeable change in oil pressure with 'synthetic' Rotella or Mobil I?

Happy Motoring, Mark

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DrDKW

This is NOT an oil thread!

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Thats pretty much unavoidable.

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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)