BC

DITTO! I forgot to ask about that here. I think (opinion comming) that that makes that oil useless to me here in SoCal.

Doug Hillary

Hi Brendan,
the old Delvac 1 5w-40 (M1 T&SUV 5w-40) is still available. The T&SUV version in the US has been renamed but the formulation remains. Delvac 1 5w-40 is still available from Commercial sources - Truck Stops/Distributors etc- as it is here in OZ and around the World

Rotella T 5w-40 is a Group 3 hydrocracked synthetic oil and is an excellent product
Delvac 1 5w-40 (M1 T&SUV 5w-40 etc) is Group 5 synthetic with a significant Ester content and some seal swell benefits etc too

Regards
Doug

FlyingDog

Last time I went to Walmart they were out of all the 5qt jugs except 10W30. I did still see the tag on the shelf for 5qt 5W40 and they had 1qt bottles of it.

Rotella-T is what is in my leaking 928.

BC

The M1 T&SUV oil I saw, that was in the same place the old 5/40 was, is now 5/30 Doug.

I did try it (5/40) but it splashed so much in my euro that I had to stop usuing it. Too much was sucked into the intake. WAY too much. Usuing 15/50 stops that, and it never gets below 50 (F) here anyway.

Doug Hillary

Hi Brendan,
as I recall there are two versions sold in the US - a 5w-30 and the "original" 5w-40 - even perhaps with different names

They are not sold in OZ

Never heard of the "splashing" problem though! And never experienced it in any engine family using it here

Doug

JTM

New M1 5W-40 here:

http://www.mobiloil.com/USA-English/...uck_5W-40.aspx

In addition to the name change, the new product lost the SL API designation. The diesel only designation(Cx)would appear appropriate for diesel engines only. I say "appear" because it has been speculated that Mobil, in an attempt to sell its other M1 oils to gas engine customers, simply changed the name of the 5W-40, maintained the diesel rating, and targeting it for the diesel truck market. Marketing only? Doug, what are your thoughts? Is the 5W-40 still appropriate for gas engines?

Normy

Just to add fuel to the fire....

-In college, they taught us to never change from dino-juice to synthetic oil. Why? Well, after years and years of running on dino, your engine develops deposites in specific places where the oil stagnates. These gummy deposits, called "kudos" for lack of a better word, do no harm and are happy to grow through the life of your engine. Until you switch to synthetic...

Then they come loose. They dislodge, not only from the better lubrication provided by synthetic oil, but also because the synthetic oil contains different detergents and eventually breaks them free. Cleaner engine is a better engine right? Wrong. Those now-free kudos need to go somewhere, and it is possible that they can come together and form a blockage at some important point, like the entrance to one of the bearings. In short order, your engine has a "heart attack" and you can potentially do damage to a bearing or worse. Aircraft reciprocating engines are always run on either dino ["ashless dispersant oil"] or synthetic for their whole life just for this reason. Turbine engines are so sensitive to oil that they even require you to use the same BRAND for the whole life of the engine!

I recently changed from Castrol 20/50 on my '85 S2 to Delvac based largely on what Hillary has posted on here. I haven't noticed any change in leakage [I have a small leak from the pan], but nor have I noticed any change in useage...or much of anything. Damn that stuff was expensive though....

N!

j.kenzie@sbcglobal.net

Normy,
Same for me. Seems to smell better (less) too.
Bought 4 gal.
Dave McK.

BC

Unfortunatley, in san diego walmarts, where I buy my oil, there has been a serious shortage of mobile 1 products that I buy, other then the norma, 10/30 stuff which I do not. I may just simply switch back to redline or amsoil just so I can buy cases and cases and simply have them show up at my door. COnstantly having my wife go to wally world to look to no avail is taxing my marriage.

FlyingDog

Brendan, sadly my local Walmart has gone the same way. They still carry 15W50, but the rest is 0W20, 0W40, 5W30 T&SUV, and 10W30.

Doug Hillary

Hi,
JTM - I suspect that Mobil are doing some formulation and Brand engineering along with a little more Market "positioning"! IMHO - they are a disastrous Marketing organisation in OZ - especially with Delvac. Then of course it is a Commercial oil and known well to Commercial users

Observations:
a) I think the new API SM 10w-30 vesion of M1 "T & SUV" is being targeted for CAFE reasons
b) The new M1 Turbo Diesel 5w-40 to API's CI-4 Plus spec is still lineball with Delvac 1 5w-40
c) Delvac 1 5w-40 (from whence the original M1 T&SUV 5w-40 originated) is still the same but it did have a formulation change about two years ago. This made it a little more viscous at 40C (102cSt against 92cSt) but retained its other qualities and some were enhanced - at this stage T&SUV then appeared on the Market in the US

I use Delvac 1 5w-40 and keep a stock of 2 x 20 litres. It is used in a variety of my engines from my MY89 S4, through Benz diesels & petrols to GM V8s, RAV4s, VWs and etc. Great in ride-ons too!
I buy this from a Mobil Distributor and it is available from Mobil Truck Stops and etc on order
For my heavy diesels we use bulk storage for Delvac 1 5w-40 at the service workshop

If I lived in the US I would be happy to use either of;
1 - the "new" M1 5w-40 Turbo Diesel (API CI-4 Plus) oil, or
2 - Delvac 1 5w-40

As mentioned earlier there are many great oils available in a 5w-40 viscosity that may be suitable for a 928

Normy - I am pleased to see your change was as predicted. This has always been my experience over the last decade or two. It was not this way in the 1970s but oil technologies have moved on

I contacted the originater of this thread privately and provided him with a procedure to consider when changing form a Mineral to a Synthetic engine lubricant

Regards
Doug

SeanR

I'm very glad this thread was bumped back up. I would not have given it another thought on switching oil. I always ran Royal Purple in my boat, but use MB-1 in all the vehicles and was going to do that in the next week or 2 in the S4. Now I just need to do some record search on mine to see wtf was being run in there.

I do know it is clean tho.

JTM

Thanks Doug, I always value your opinion and huge amount of information that you provide.

Tom928

Well it has been 2 weeks now since I switch over to synthetic on the 81. I have been driving the car everyday since and checking every two days or so and thus far - no leaks or issues.

Im sure its my imagination, but sometimes it seems that the engine is actually running better.

spinaker

I use Mobile 1 15-50. I bought 8 litres today at the only place in town that I could find that sells 15-50 and they told me it in now discontinued from their inventory list. It was all the inventory they had or I would have bought a case.

Don't know if that means Mobile is discontinuing it or if "Parts Source" is. Intend to find out.