DJF1

Yeap, I agree. 15-50 as per the manual I used to use year round in Houston due to the weather conditions and because I tracked the car many weekends. Up here in Vancouver I dont drive the cabrio in the winter and when I do its either a spirited spring/summer drive or an AutoX which means high revs and loads on the engine. So at least for my use I'll stick to the 15-50 for now, although my car presently has a fill of Mobil 1 5-50 which we have in Canada!

I'm not sure at that time if there were 5-40 and 5-50 oils, but I think the dispute at least on the 993's is with the 0-40, key value here is the 0 which as you can see its not in any oils that Porsche used to recomend at that time. The argument here is that 0 weight is too thin for our engines the way they were built ( tolerances, gaps etc) where for the newer blocks which are different than ours, the 0-40 is essential as the 15-50 maybe too thick.

Thanks again Doug for the recommendations.

tj90

+1 - Isnt a shame that the oil companies dont allow more straight forward education about their products to some of their most loyal customers - the enthusiast, the technicians the mechanics? Seems like AMSOIL attempted to educate the public but the message is lost in their AMWAY like distribution model...

Its frustrating to read the back of an oil bottle and its a generic 2 or 3 statement. To call tech support and get some generic response from the guy on the other end. Its great to have open dialogue and discussion disagreement. Ive learned more about oil in the last 3 months! Also appreciate other sites like BITOG as well.

Sad but true story - I went to one of those quick lube places and specifically talked to the manager. I asked if they used GL4 gear oil for transfer cases (my wifes 4x4). The guy looked confused and had no idea what I was talking about. For those that dont know, the most common gear oils - GL4 and GL5. GL5 lube is for hypoid gears in differentials - NOT for use in transfer cases without hypoids. M1 GL5 gear oil specifically says not for use in GL4 applications. He arrogantly said that they ONLY use 75w90 or 80w140 depending on the manufacturer recommendation. To think this guy may be filling transfer cases of expensive SUVs with GL5... And lube is his business. I bet for oil changes, they put whatever they want in the car and send you on your way. Morons!

Doug Hillary

Hello,
some questions answered in order;

FLYT993 - It is certainly more cost effective to use a non boutique product when the specifications are identical. Boutique blenders buy from a very few base-stock and additive package suppliers
This is NOT to say that the "boutique oils are not good products - they are! But they are simply NO better than the others!!

Esters in lubricants have been a reality for around 60 years. There are a bewildering range of esters and ester blends - some oils can have up to 25% of certain esters and a mid range base stock and outperform some oils advertised as "double ester" and etc. "Polyol esters" are derived from reacting fatty acids with alcohols. Most of these products are developed and supplied by ExxonMobil - the Worlds largest supplier as I recall - Boutique blenders are their customers

The base stock is actually "only" a carrier, and as noted above it is what is blended into and with it that makes the desired specification/characteristics of the end product. Generally, the higher the quality of the base stock the better the end product will be without the addition of too many "corrective" supplements. Advancements in recent years in processing Group 3 base-stocks has produced a great range of "semi-synthetics" that outperform some old fully synthetic lubricants

Castrol's Syntec 5w-50 is a Group 3 "semi-synthetic" and a good product. It is not Porsche Approved anymore. Three earlier versions were on Porsche's Approved List for MY1998
I would use it in a Porsche instead of Mobil 1 15w-50 due to its better low temperature "warm up" performance - and instead of more expensive Boutique products

tj90 - The "Handbook" is always superceded by a TSB. The Handbook's recommendations apply to a wide range of export and availability issues and rapidly become outdated in today's World

5w-40 lubricants have been around for many years dating back into the late 1970s-1980s
The 0w-30, 0w-40 lubricants are at least 12 years old

In certain applications a mono-grade oil (SAE30, SAE40) may perform better than a multigrade. Synthetic SAE50 oils are the prime lubricant in Class 8 truck gearboxes and are very stable

New multi-grade viscosity ranges have been developed since 1958. Until then "the" oil was 10w-30. The BMC Mini caused the need for the next one - 20w-50!

DJF1 - One great misconception is the relevance of the starting number of a multigrade lubricant. These following lubricants -0w-40, 5w-40, 10w-40, 15w-40, 20w-40, 25w-40 and SAE40 - are actually all SAE40 lubricants.

It is how they arrive at the 100C rating point that tells the real story!
The determining factor here lies in the lubricant's base and formulation. The higher the arbitrary Viscosity Index (VI) number is the less the lubricant's "perceived" viscosity changes from two points of reference - usually 40C and 100C. This is why looking at the perceived viscosity of M1 0w-40 and a 15w-40 HDEO gives a wrong impression. At 100C they must be in the same range

The thicker the oil at start up the longer the oil will be in either lubrication system by-pass or in full flow filter "differential" by-pass - or both!

In most Porsche engines the operating "core" oil temperature is around 93-98C. At this point (93C) a SAE40 lubricant has a similar viscosity to many SAE50 lubricants at 100C

According to the J300 SAE viscosity classifications, 0w-40, 5w-40 and 10w-40 must have a minimum 2.9cSt. The others must have a minimum of 3.7cSt

I hope this is of interest

Regards

RallyJon

I think this is the single most important thing for owners of air cooled and/or turbocharged engines. The ability to provide reasonable cold starting AND handle 300º+ temperatures AND last more than a couple of thousand miles is important only to a small group of cars. While many oils can do two of those things, very few select oils are truly great at all three.

The discussion always seems to focus on additives, but who cares what additives you have when your poor engine is trying to pump 20W50 on a freezing morning. Or when you're on the track in summertime with an old fill of 0W40 that's stretched to the breaking point?

The oils that handle all the conditions that 993 owners encounter are very special. It starts with the qulaity of the basestock and the amount of "corrective" supplement and extenders (or hopefully lack thereof) required to make the basestock perform.

There's a reason Redline and Motul (and Delvac1 for that matter) cost so much.

FLYT993

And the discussion continues....

Doug: Since the Castrol 5w-50 is a good product, and seems to offer the widest range of protection...why is it no longer on Porsche's Approved list, when it meets and/or exceeds all of the critical criteria for our air cooled engines?

RallyJon: Your comment seems to run counter to what Doug has stated. Do you believe that even though RedLine, Motul, and Delvac1 ("boutique oils) are more likely than not obtaining their high quality base stocks from ExxonMobil or others, EM is still using an inferior base stock? Please review the data I've posted here, as well as the PDS from Redline.

Secondly, why the can't we get M1 5w-50 here in the US? I had to go to the "Australian" version to get data.

http://www.mobil.com/Australia-Engli...bil1_5W-50.asp

Specifications and Approvals:
Mobil 1 5W-50 meets or exceeds the following industry specifications:
ACEA A3,B3,B4
API SM,SL,SJ,CF

Mobil 1 5W-50 has the following builder approvals:
Daimler Chrysler 229.3 / 229.1
Porsche Approved
Volkswagen 505.00

Typical Properties:
SAE Grade 5W-50
Viscosity, ASTM D 445
cSt @ 40º C = 104.9
cSt @ 100º C = 17.5
Viscosity Index, ASTM D 2270 = 184
Sulfated Ash, wt%, ASTM D 874 = 1.2
HTHS Viscosity, mPa·s @ 150º CASTM D 4683 = 4.21
Pour Point, ºC, ASTM D 97 = -54
Flash Point, ºC, ASTM D 92 = 236
Density @15 ºC kg/l, ASTM D 4052 = 0.859


In looking at the same values for the Castrol 5w-50, I get the following:

Specifications and Approvals:
API SM, SL, SJ, SH, CF or CD is
recommended. Exceeds European ACEA: A3, B3, B4; Ford WSS-M2C931-A and the engine protection requirements of GM 4718M, ILSAC GF-4

Typical Properties:
SAE Grade 5W-50
Viscosity, ASTM D 445
cSt @ 40º C = Not Published
cSt @ 100º C = 17.4
Viscosity Index, ASTM D 2270 = Not Published
Sulfated Ash, wt%, ASTM D 874 = Not Published
HTHS Viscosity, mPa·s @ 150º CASTM D 4683 = Not Published
Pour Point, ºC, ASTM D 97 = Not Published
Flash Point, ºC, ASTM D 92 = Not Published
Density @15 ºC kg/l, ASTM D 4052 = 0.852
Low Temperature ºC
Cranking Viscosity, cP max = 6600@ -30
Low Temperature ºC
Pumping Viscosity, cP max = 6000@ -35

If we assess these lubricants based on the data and data alone, which one is best? In loooking at the values, they all seem relatively close, which would support Doug's position of "similar specifications" leveling the performance/quality field. The $64 question for me is, is there a difference between these lubricants that makes a difference? Based on the data I don't think so....but again, I defer, because I am in no position to assess with the level of detail and knowledge of Doug, TJ, and Steve.

I couldn't find similar Data Sheets for Motul.

BTW, I do love this thread, and am not bored!!

RallyJon

I don't know what that means in this context. Either they are or they aren't. Not for Motul of course. But you could drop Redline an e-mail and ask them. If EM has a business supplying customer-spec oil for other companies, does that preclude them making oil to their customer's spec which is not identical to oil they sell themselves?

tj90

Does anyone have the cst value for m1 15w50 at 40 and 100C handy? Theoretically, it should be the same as the castrol and mobil 5w-50. Im curious what it is at 40C...

FLYT993

RallyJon--

That comment was based on Doug's previous comment that "Boutique blenders are their customers"....i.e, I don't know (factually) that ExxonMobil supplies Redline's base stock, but they could.

FLYT993

TJ90--
Mobil 1 Extended Performance 15w-50

Viscosity, ASTM D 445
cSt @ 40º C = 138
cSt @ 100º C = 18.0

tj90

Thanks!

Doug Hillary

Hello,
to comment on some issues raised;

Rallyjon - Your comment "The oils that handle all the conditions that 993 owners encounter are very special." is perhaps a little presumptive. If Porsche felt that way too they would certainly prescribe special lubricants either via an individual TSB or in their "General" Lubricants TSB

In fact Porsche obviously have enough data to ensure that the 993 is well looked after within the current and past TSBs that take on board all engines back to 1983
One thing they do prescribe is that only 0w-40 viscosity lubricants be used in Turbo Cayenne engines and that a specific VW specification lubricant is used in the V6 Cayenne

I believe Worldwide that there is only about five Lubricant base-stock suppliers and a similar number who provide Additive packages. This is of course via Subsidiaries and etc, and EM has at least one joint venture in the Additive supplier field. Shell, BP, EM and Chevron (etc) are all Manufacturers of very advanced "hydrocracked" Group 3 (high viscosity index) base-stocks

Blenders "do their own thing" with supplied product (base-stock & additives) and it is most likely that Motul, Repsol, FUCHS, Repsol and etc use some EM components in their lubricants
A good initial suggestion that an oil may have a significant ester component in its blend is a lower than average Pour Point and in some cases its price. Some "old" ester based (and many mineral based) lubricants tend to get thicker with use - something that Porsche obviously is very anxious to avoid!

In some Countries EM (and others) do blend/supply Customer Spec lubricants to their specific Brand name

IMHO they and the others are most unlikely to supply leading edge components that they use in their current products to another party! They keep the best for themselves but many advanced "ester" components are sold on the open market.

FLYT993 - I suspect that Castrol simply did not seek to have it Approved - or it simply failed! Castrol have about four 5w-40 and one 0w-40 lubricant on the Approved List

Sadly the data that is marked "Not Published" in the Castrol 5w-50 specifications does not enable a direct comparison of viscosities and etc. It is hard to say if they are "similar" but having the ACEA's A3/B3/B4 on the label and spec sheet is a good indication of quality just below Porsche's Approval
I cannot calculate the 40C and 150C viscosities for the Castrol product as the Viscosity Index is "Not Published"

And to answer your $64 question - IMHO one is Approved by Porsche and one isn't

For the future there is also a Group 6 for lubricants - promulgated in 2003. Predicated especially for PIOs which are similar to PAOs as they are synthetic linear chains of alphaolefins. These fully synthetic lubricants will again change the goal posts

Regards

MarkD

OK, really interesting and educational. I have one question

Doug: If you had a 3.6L NA Flat 6 Porsche engine to be used in a mild to hot climate (50-100F temp range), what M1 oil would you run?

Doug Hillary

Hi Mark,
firstly I would use a 5w-40 (or 0w-40) Approved oil off the TSB List
Shell's Helix Ultra 5w-40 or Castrol's Syntec 5w-40 are very good Group 3 products - M1 0w-40 is the best of this Approved viscosity

Or, if I could not find an Approved oil I would use Delvac 1 5w-40 (also sold in USA as M1 Turbo Diesel Truck 5w-40) which is a Group 4/5 ester fortified HDEO. I use this in many of my engines and have done so for a decade or so

Regards

kev

I have 3 quarts of the SL formulation 15-50 EP that I am not going to need. $30 bucks gets it to your door.

Nevermind what Doug said.

FLYT993

My 15w-50 is going back to WalMart because of what Doug said, and because of what Porsche said. M1 15w-50 isn't on their approved list anymore...or did I just print out an obsolete TSB???