I emailed Castrol for their direct input and here's their response. Nothing new, but direct from Castrol and at least a consistent message.

Thank you for contacting Castrol North America,

The latest API SM / ILSAC GF-4 category calls for reduced Zinc and Phosphorus levels to allow extended catalyst life in current model vehicles.
There appear to be field issues associated with the SM/GF-4 oil's level of anti-wear in the classic car engines known as flat tappet cam engines. The current late model passenger car engines are not flat tappet cam engines and have no reported field issues related to the level of anti-wear chemistry in the SM/GF-4 oils.

Product Recommendations for Flat Tappet (Solid Lifter) Cam Engines:
Castrol Syntec SAE 20w-50 (Recent reformulation identified by "Recommended for Classic Cars" text on back label) (min Zn = 0.12 = 1200 ppm)(full
synthetic)

Castrol Consumer Relations

 

Oh! thanks for the info.. just about to do the oil change in a few hours. Looks like i'm going 20w-50!!

 

Well, that will satisfy your ZDDP, but you still have the issue with the thick oil on cold starts.
If anybody ever suffers from premature ejaculation, all you have to think about are the horrid images of what overly thick oil does to your engine, on a really cold start-up, and you'll be instantly grossed out.

 

Why not look at an Amsoil 15w50 Dominator.... It's high on the ZDDP and a little thinner....

 

I too worry about the cold start of a 20w50 and I would love to go with something thinner but Amsoil is hard to find around here. I'm on the hunt for high ZDDP in a lighter oil for cold(er) weather use.

Cheers

 

The thing is my car not a daily driver. I don't need to drive it in weather colder than 0c ambient temp. I'm just not going to "cold" start it.

 

You can order it online. www.amsoil.com

 

aren't our engines hydraulic lifters (flat, but not solid) ?
solid lifters, like a hot rodded chev small block

good read:
http://www.hotrod.com/techarticles/e...ech/index.html

http://www.thirdgen.org/sbc-camshafts-primer

 

I hate canadian tire.... they don't have Castrol 20w50 synth and they said they can't order it. i have a feeling though that the person i was talking to was a complete idiot... might just go with the same oil in the car .. Castrol 20w50 GTX dino oil. Super easy to get! and cheap!

 

LOL! While spending ridiculous sums there, I never get oil and important car stuff there... Electrical connectors, tools and car cleaning stuff....

 

Ok Canadian tire has Castrol Syntec
Product #28-9225-8
4L
$24.99 Reg. $39.99 / Save 35%

5W40 oil
That is pretty cheap for Synthetic oil... OntarioTurbo runs this oil, but then svtlrtls emailed Castrol Oil and they recommended 20W50 Syntec oil.. I'm sure one of these days i will select an oil and move on with my life.

oh and almost forgot. One of the guys who changed the oil wanted to trade his 1999 Mercedes SL500 V8 for my car..

 

Alright finally done the oil change.... went with 4.4L of Castrol Syntec 5w50 synthetic oil and 2.1 literes of Castrol 20w50 GTX dino oil.... car is happy.

 

Hi,

Reading http://www.lnengineering.com/oil.html, I tried to source Brad Penn, Swepco and Motul locally and only found a distributor for Swepco ($205 per case of 24 qts) so I jumped that ship and started looking for something easier to source.

I run motul in my motorcycle but I'm still waiting for them to respond to my questions.

I contacted Shell Canada and here's what they said.
"Formulation are priority information, we do not disclose this. I am assuming that your vehicle is a 1988 Porsche 944 Turbo. All the Rotella T oils, as commercialized as we speak by Shell Canada, have a ZDDP in the 1200ppm vicinity. Per my source the recommendation for the above mentioned vehicle is for API Service SF/CD, SG, SG/CD, and almost every SAE viscosity grade on the market can be used, whatever it is mineral or synthetic. 5W-30, 5W-40 and 5W-50 are the recommended SAE viscosity grade for all temperatures. So Rotella T 5W30 or 5W40 can be you for year round. A SAE 10W-40 is recommended from -20C to +35C. So Rotella T SB 10W40 could be used in that ambient temperature range.

Regards.

Xavier Henry
Technical Help Desk
Fuels & Lubricants
Shell Lubricants - Canada"

 

Hi,

Here's Motul's response

"A good product for road would be 6100 Synergie 10W40, for road/racing applications 300 V Chrono 10W40 and for race application 300 V Competition 15W50. These three products have a high level of ZDDP you are asking about (over 1100ppm). Remember that it is not only the ZDDP but a balance of all components that make a better oil (ester, double ester…)"

And Charles N. recommends the 300V so again, some consistency in the information I'm seeing.

Cheers

 

Yes, saw the sale on at Canadian Tire. I will be picking some more up at that price. Works out to about $45.00 for an oil change with Mahle filter. Not bad.