I said it before and I'll say it again...I love this forum!!

Several things....

Mark T. Yes I always use the Search feature to see what people have said before me. None of my posts have been "original material". But my questions are too specific in nature and I add constraints on you to find the best path. In this case I needed feedback specific to 5W40 and 5W50 type oils appropriate for the Phoenix area.

And Tommy583 is exactly correct...what fun is search when I can get your wisdom with a personal touch as Smallblock454 gave us. He was totally over my head and then 78F350 swooped in with a translation. Perfect!!

So, when it's all said and done, it took everyone's passionate suggestions including my mechanic's personal choice and ran the numbers using Amazon's prices converted to a per quart cost (see below). Out of this, Rottela T6 was the winner in happy users and lowest cost ($5.52 per quart). In my case I decided to stick with my mechanics suggestion and oil of choice and go with Total ($7.00 per quart). The crappy part is, when I ordered the oil, the three pack was not in stock. That's ok if I don't have to wait a long time for it. If I buy Total in a smaller quantity (5 qt) the cost jumps to $9.31 per quart. No thank you....I'll go with Rottela T6 in that case.

So...yet another oil thread has proved highly educational (and entertaining).

Thank you all!!!

This reminded me, when I have bought oil in 2x 4qt containers, it is ALMOST enough. My cars need 8.5 qts.

Hi 78F350,

Low SAPS. There are different ACEA standards for low SAPS oils. Some have a lowered HTHS. So i have to go more in detail:

A1/B1:
Standard quality, SAE 0W-30, 5W-20, 5W-30, 10W-30, normal oil intervals, lowered HTHS-viscosity (2,9 - 3,5 mPa*s)
not recommended

A3/B3:
Higher quality, shear stable, SAE 0W-X, 5W-X, 10W-40, 15W-40, 15W-50, 20W-50 for longer intervals, high wear protection, HTHS-viscosity (>3,5 mPa*s)
Recommend, but engine wasn't designed for the longer intervals (means engine sensors test the engine oil quality permanently). So can be used, but has to be changed in the intervals given by Porsche. Yearly or 15.000 Km.

A4/B4:
like A3 / B3 but also for DI-Diesel including Common Rail-Diesel, SAE 0W-30, 0W-40, 5W-30, 5W-40, 10W-40; A4 reserved for DI-Otto, high wear protection, longer intervals, HTHS-viscosity (>3,5 mPa*s)
Because it's a Diesel engine oil it had complete different detergents and much more. My point of view: not recommended.

A5/B5:
Performance like A3 / B4, SAE 0W-20, 0W-30, 5W-30, but lowered HTHS-viscosity like A1 / B1 (2,9 - 3,5 mPa*s), for longer intervals, lower fuel consumption.
Absolutely not recommended. Engine wasn't designed for that.

C1:
low SAPS oil with lowered HTHS-viscosity > 2,9 mPa*s, low viscosity (0W-X, 5W-X), Performance like A5/ B5, but with lowered sulfate ash, phosphor, sulfur.
Absolutely not recommended. Engine wasn't designed for that.

C2:
mid SAPS Öl with low HTHS-viscosity > 2,9 mPa*s, low viscosity (0W-X, 5W-X), Performance like A5/ B5 but with higher sulfate ash, phosphor, sulfur as C1-04.
Absolutely not recommended. Engine wasn't designed for that.

C3:
mid SAPS Öl with high HTHS-viscosity > 3,5 mPa*s, low viscosity (0W-X, 5W-X), Performance like A3/ B4 with with higher sulfate ash, phosphor, sulfur as C1-04.
Depends on sulfate ash, phosphor, sulfur. As said - no sulfur and sulfate ash would be best. I don't know about the US fuel. Sometimes fuel does also contain sulfur.

So i always go with a A3/A4 oil that also has a A40 Porsche approval.

A good HTHS is above 4.0. The oil i use at the moment has a HTHS mPa·s at 150ºC ASTM D 4683 of 4.3.

And hey, this is only my personal opinion and all marketers, believers and everybody else can do and like and use what they think it's right for their engine. ;)

Regards, Markus

+1 on the 5w-40 Liqui Moly. I like it!

Ever since day one on my VW 1.8T I've used Rotella. Even though it was never on P cars "Approved list" of oils, I figure its good enough for my NA 986. Walmarts always got them for a good price.

I order Liqui Moly from Amazon and have it delivered to my door step