901aero

Just wondering what has developed in the engine oil industry concerning our cars (and many other "older" engines) since the last time we had a real round and round with it here on RL. At last time it was decided that the SM rating was not good and the older SL-CF rating was not to be found.

Now I know Mobil 1 has a new 15-50W but it's rated SL-SM which seems like two mutually exclusive ratings. Any thoughts (Steve @ Rennsport-- are you there?) I know, I know, here we go again, right?

PS: I also recently read that GM will soon no longer offer it's EOS. True?

dcdude

I think EOS is slated to come back, and that Brad Penn and Swepco are the current best choices in high ZDDP oils.

RallyJon

SM is bad. If it says SM don't buy it. We want oil that explicitly cannot meet SM specs.

Adrienne

The latest (or maybe the month before) Panorama has a tech article about it, with some links to websites for more info. I'll check for it when I get home tonight and re-post unless someone else can find it before then.

I now use ELF synthetic rather than Mobile, for probably a year now. It's about the same price, and has the correct additives.

dbf73

Adrienne - which Elf oil do you use and where do you buy it? mail order?

Flying Finn

I use Redline 10w40

901aero

I have found a Mobil 1 marked for SUVs or something. It's a 10W-40W and it is rated CF. I used it in my 1969 912. And also put it in my 993 last oil change. No SM rating anywhere on it.

Gus Sem

How would SM hurt my engine? Thanks.

Gus
'95 C2

Stealth 993

Amsoil

Adrienne

Elf Excellium NF 5w40. More info:

Spec sheet is here (download was not allowed, sorry):
http://www.finalube.com/Product_Data..._Data_Main.htm

I buy it directly from my shop, but a quick net search shows it can be ordered.

SL/CF, recommended for "vigorous" driving.

901aero

Do a search and you will find a whole bunch of info on this. It's all about the "new" generation of oils (rated SM) not having the same amout of Zinc and other additives that the "old" generation of oils (rated SL- CF) had. It is widely believed that this is a bad thing for our engines and it may be causing premature and significant wear on the valvetrains, valve guides, etc.

Many mechanics have reported noticeable engine wear on engines that have been recently disassembled that seems excessesive and unexplainable. Many now believe the culprit is the oil.

Steve Weiner-Rennsport Systems

Chuck,

The new version EOS doesn't have the same ZDDP levels that the old product had, according to the folks ats GM that I spoke with. The EPA mandated a reduction/elimination of that stuff and since the General sells a LOT of cars & parts, they complied.

There are other similiar products offered by Crane & Comp Cams used for break-in that would work.

Basically, if one uses a good oil in the first place that contains what these engines need, one won't need to be concerned about additives of any kind.

FLYT993

I'm on a blend of Redline 15W-50 and 5W-30, 7:3.

Also, when I was at the shop picking up my RedLine Oils, they suggested I look at Joe Gibbs oils...
joegibbsracingoil.com

BobbyT

Hi Steve,

What oil are you using for street-driven stock 993s now at Rennsport?

Steve Weiner-Rennsport Systems

Hi Bobby:

We abandoned Mobil engine oils well over a year ago after multiple camshaft/rocker failures and now use, recommend and sell both Brad-Penn 20w-50 and Swepco 306 in two viscosities.

Besides offering the needed protection, we picked up some power on our engine dyno from the use of these oils, as well.

We use these in all street and racing engines.