My stock '87 Carrera Targa is in need of more winter
compatible oil. I have moved to Nederland, CO.

I have always used Castrol 20W50.

My understanding was that synthetics were not for 911's.
(also adding a $6 quart every 600 miles doesn't sound fun)

The manual calls for 10W40 or 10W50.

any recommendations from cold weather 911 experts/freaks?

For several years now, Porsche has only recommended synthetics for 1974 to current. I've posted the recommendations previously, you can search for those, or they are periodically listed in Pano or on the PCA tech website, too. There have been concerns about synthetics in older 911's, but generally you'd be safe switching on 1979-on 911's. I switched to Mobil 1 in my 1981 911SC at 100K miles and didn't have any issues. If you're adding a quart every 600 miles, that's around the Porsche spec for oil usage, and well below the average of a quart every few thousand miles (unless those are track miles, in which case disregard this comment). With all that said, I'd use Mobil 1 0W-40 for winter oil, however, if you want to stick with Dino-based oil, I'd look to 5W-30.

I used Castrol blended (dino-synthetic mixed) oils in the winter with my 73S and that worked nicely...

I don't know how cold it gets in CO but here in New Zealand, -10c (-25f?) is the worst we can expect.

I swear by Castrol Magnatec 10w-40 (blend). I have tried Mobil 1 and Valvoline Durablend but for my money Castrol has come out on top. Reasons are subjective I know but one difference is start up chatter.

If the car sits for any period of time i.e. several days, on start up with Magnatech, I would swear the engine noise is somewhat reduced vis-a-vis the other 2 oils especially against the Mobil 1.

To me, start up protection is the key issue when it comes to oil.
Next key issue, no matter what you use, is to replace the oil every 6 months regardless of mileage......

thanks lewis9113.2, that is great info

M1 15/50 works great hot or cold, and that includes really hot and really cold

Hi,
this link may assist;

http://www.landsharkoz.com/techtips.htm

Check under "Lubricants for the 928"

Porsche engines require a minimum of a Group 3 synthetic or semi synthetic engine oil with a High Temperature High Shear (HTHS) viscosity above 3.5cSt and this will not be found in oils of ??w-30

The minimum ACEA specification should be A3-96/B3-96 (relevant to foaming, deposit control,viscosity "stay in grade" and etc) and the minimum viscosity must be ??w-40. A 0w-40 or 5w-40 viscosity synthetic is ideal for all year use (ambient <-20F to 110F>).
Mobil's twins M1 SUV 5w-40 or Delvac 1 5w-40 (mixed fleet) are ideal for use in our cars

Many people use M1 5w-50 or 15w-50 with great success too - do not buy other than the latest "SuperSyn" formulation

Due to their superior flow characteristics M1 oils tend to show a slight reduction in oil pressure when hot

There are many excellent lubricants around but Porsche's minimum specs need to be observed

Regards
Doug

What do you guys think about AMSOil Euro-Spec Synthetics, specifically, as compared to the mention of the M1 SUV 5w-40?

(Specs here: http://www.amsoil.com/products/afl.htm)

Here is information on the Porsche approved oils in North America, as posted on the PCA web site:

Porsche's latest approved list of oils appeared in Technical Bulletin 1701, and they are all synthetic:

Castrol Syntec 5-50 (G)

Mobil Mobil1 0-40, 5-40 (GL) [Correction 5/2003: used to say 5-50, correct listing is 5-40]

Sunoco Synturo Gold 5-40 (GL)

Havoline Formula 3 Synthetic 5-40 (GL)

Valvoline high performance synthetic 5-30 (GL)

(GL) means it has good "light running properties" such as what we are discussing above with respect to cold winter performance. So the Castrol 5-50 is rated too high for this. In other words, no one is questioning the "50" part of their designation, but the "5" part is in question. We can assume from this that the 5-50 can be more safely thought of as a 10-50 or 15-50 for this discussion.

Likewise note that your Mobil1 15-50 is NOT approved by Porsche for this (year-round use).

Since the list above was printed, there is a newer list as of 5-23-03 (though not specifically for 993, there are separate lists now for Boxster, 996, Cayenne, GT3, etc) which lists dozens and dozens of brands and products. All are synthetic or synthetic blends. Unfortunately the list is for the European retail marketplace, not for North America, so the list is in need of some heavy translation to sync up with what we find in our stores and shops over here. Just try asking for Hunold Schmierstoff Eurolub Synt 5W-40 or Meguin Megol Super Leichtlauf 5W-40 at your local WalMart and you will see what I mean.

Joel Reiser - PCA WebSite - 7/11/2003

---------------------------

Note, for heavier duty, ie track, use, Mobil 1 15W-50 or other synthetic xW-50, or dino 20W-50 is often used.

Hi,
Bill - via the Joel Reiser article;
"We can assume from this that the 5-50 can be more safely thought of as a 10-50 or 15-50 for this discussion."

The Castrol Syntec 5w-50 referred to and the Havoline Formula 3 5w-40 are both Group 3 synthetic lubricants - the minimum Porsche level

The winter(w) viscosity rating for an engine lubricant is indeed critical as it denotes in fact some other things too - its ability to meed the viscosity designation requirements and it also provides an indication of its ultimate pour point and its ability to "stay in grade"

Winter viscosity ratings of 60 000cP for low temperature pumping are:
0w - @ -40C (3250cP @-30C)
5w - @ -35C (3500cP @-25C)
10w - @ -30C (3500cP @ -20C)
15w - @ -25C (3500cP @ -15C)
20w - @ -20C (4500cP @ -10C)
25w - @ -15C (6000cP @ -5C)

The Max. low temperature cranking viscosity is shown in brackets. Note that the viscosity of a 25W rated oil at -5C is almost double the 0w oil at -30C

The problem with some 0w-40 oils is their inability to stay in grade and the official ACEA A3/B3 ratings ensure that it does meet this requirement. Porsche's "Approval" also relates to a number of special tests that it insists upon.

Mixed fleet Heavy Duty Engine Oils (HDEO's) are not tested by Porsche now (they were once factory fill in 911s/912s) but they will meet all requirements. Delvac 1 5w-40 and Shell Rotella T 5w-40 synthetic are such oils - both have a HTHS of 4+ and therefore far exceed Porsche's requirements

Mobil 1 5w-50 is sold here in Australia and in Europe and is a very popular lubricant. This oil is suitable for all year use and it has a pour pount of -54C the same as M1 0w-40 but it is 30% thicker at 40C. This is a Group 4/5 product

Fred - "oils ain't oils". There are no really bad oils sold and some are a little better than others. Tribologists generally agree that Group 5 Delvac 1 5w-40 is the best oil around and readily available. It is virtually the same as M1 SUV 5w-40. I have used Del 1 in my heavy truck fleet for many years

The Group 4 Amsoil product specification you mentioned reads well. The problem is that I do not believe it has been tested and officially approved via the API and ACEA protocols. I do not think it has Manufacturer Approvals either but I may be wrong. This is very typical of Amsoil's marketing - many of their products do not have official approval - for what that is worth!

There are oils and the oils - those that meet Porsche's standards - ACEA's A3/B3 and the correct viscosity - are critical

I hope this helps
Doug

Doug, I use Delvac 1 in my Golf TDI as it is one of the few oils that meet the VW 501.1 (I think) spec. I am surprised that it would make a good oil for a 911 because I thought the needs of a diesel were far different than a gas engine. I think the difference is soot control in the deisel VS acid control in the gas application. Any comments? I am becoming more confused all the time about thiscomplex issue. I use Mobil 1 20W50 in the 911 and am pleased with it.

Hi Dave,
Delvac 1 5w-40 is an excellent choice in all VW TDI engines - I have never seen a bad Used Oil Analysis report on this combination

Mixed fleet Heavy Duty Engine Oils (HDEO's) meet both diesel and petrol engine API standards and some meet the combined ACEA standards too - or exceed them.
Delvac 1 5w-40 is an API "CI-4(diesel)/SL(petrol)" (CI-4/SL) quality standard oil and meets the highest current standards. We can expect CI-4plus/SM conformity soon

Soot control is but one issue - the HDEOs (mineral and synthetic) are especially tailored for anti foaming, valve train anti wear and deposit control in the fire belt area above the top ring. Acid control is a vital part of any HDEO and their Total Base Number (TBN) which is a measure for acid control - is much higher than conventional oils. They work especially well in turbocharged and supercharged engines due to their high HTHS viscosity and inherent anti oxidation formulation where high compression pressures and temperatures are part of the engine design

I have used mixed fleet HD engine oils with great success in petrol engines - both air (VW & Porsche)and coolant cooled (Porsche, MB, BMW and etc) - since the late 1950's. This was the only way back then that sludge etc coud be managed. Porsche specified only HD monograde oils for many years from the 1950s until about the late 1970s

At a HTHS viscosity point of about 4.5cSt the heavier viscosity oils become counterproductive due to frictional losses. This applies especially to the "ramp up" speed in turbo's and and in mains/big end and camshaft bearings where oil flow is critical but film strength must be maintained. Porsche's minimum is 3.5cSt - I prefer a minimum of 4cST

I have just pulled apart a 1999 60 Series Detroit Diesel (500hp/1650ft/lbs) engine of mine after 620k miles(1m kms) and all parts could have been reused. Oil consumption was 1ltr/6k kms - we pulled it apart as a measure/inspect project (Mobil, Detroit and I). Valve train component wear was not measurable and zero deposits were present. The critical crosshead piston and top end bearing showed no wear (this engine is prone to wear here), original hatch pattern was visible in each liner and all cam and crank bearings showed little wear and were suitable for re-use. The engine was/is on Delvac 1 5w-40 from new and the average oil change intervals were 100k kms (62k miles)> average speed life to date is 80km/h (50mph) and the truck runs loaded at 42.5 tonnes.

Used Oil Analysis from my 928 can be seen on the 928 Forum here under serach "Oil Condition Report"

As a matter of interest we recently analysed the GL5 Mobil 1 SHC 75w-90 synthetic gear oils used for 1 million kms without change in this trucks Eaton DS462 tandem diffs. and they were suitable for reuse (I changed them anyway). Castrol's synthetic Syntrax 75w-90 GL5 achieved the same results

The same applied to the SAE 50 viscosity synthetic oils used in the 18speed RoadRanger gearboxes

I hope this is of interest
Doug

I'm driving a normally aspirated 3.2 this winter in Alaska for the first time. I have switched to Mobil 1 0W-40 and have no issues with it. The coldest it's gotten has been -10 thus far. I will probably switch to an Optima red top battery soon. I'll be interested in what you settle on and feel free to check with me later in the season after the really cold....

I'm really glad to hear that the delvac 1 mixed fleet 5w40 is an excellent choice for our aircooled engines. It's readily available locally for less than mobil 1 and I had used it in my porsche 914 with excellent success year-round. I've also tried out Royal Purple's Racing oils (group 3) and they work really well, but still use m1 0w40 in my wife's 1.8T year round. Anyone else have any experience with Royal Purple, like their R21 (7w40)?

Hi Charles,
Delvac 1 5w-40 is a great performer and I'm pleased that it performs well in the 914.

Group 3 (hydrocracked) lubricants are being developed that will meet very specific applications - they will be cheaper than Group 4 and 5 synthetics and will perform almost the same.
Shell's Helix Ultra is but one and Ferrari seem to like its performance - in Australia Helix Ultra sells for 20% cheaper than Mobil 1

These oils may have a downside as the meet the API's new SM standard. My advice is to use the ACEA A3/B3 as the benchmark and API's SL/CF standards as a base line in dealing with non HDEO mixed fleet engine oils

Regards
Doug