[s-cars] 0w-40 for S6?

[Taka Mizutani]

George-
Can you elaborate on why you didn't like Mobil 1 in your S4?

I've used Mobil 1 10W30 and 15W50 in both of my I-5 cars in the past
without any issues. I used Castrol Syntec 5W50 in the 200 and had very
loud lifter tapping on cold starts, went back to Mobil 1 and had no
such issues. As such, I've preferred to use Mobil 1 in the I-5 cars-
very little oil consumption as well.

As a counterpoint, our '01 New Beetle 2.0 had massive oil consumption
issues at came to a head at about 30k miles- engine was replaced.
Prior to engine replacement, I found that Castrol Syntec 10W30
resulted in less oil consumption than Mobil 1 10W30- I have no idea
why this was the case. After engine replacement, I've run both Syntec
and Mobil 1 in the engine with close to zero oil consumption on a 5k
replacement interval. I always run 10W30 in the car, although my
mechanic tends to put in 5W50 (last oil change was not called for, he
did it anyway, ended up with a free oil change).

I'm running Mobil 1 10W30 in both our '04 Volvo V70R and '04 Subaru
STi and no issues there, either. Curiously, the Volvo's oil filler cap
says to use Castrol oil. According to the dealer, it is not an issue
to run other oils- it is not a case like the BMW E39 M5, where a
special Castrol RS 10W60 oil was specified. That's what the dealer
said, I don't know what the official Volvo line is.

There are a lot of oils that we can't get in the US- Castrol RS 10W60
is available only at the BMW dealer unless things have changed. Same
thing with Mobil 1 0W40- for the longest time, you could only get it
from the MBZ dealer, then Autozone started carrying it, now I think
you can get it in quite a few places. I had to buy 5 cases at a time
at the Mobil distributor in order to avoid $8/qt. at the MBZ dealer.

Personally, I don't think 0W40 is warranted in the I-5 Audis, although
Steve Bednarski reported to me that he had very good luck with 0W40 in
his numerous '91 200q20vs.

I have not noticed a difference in operating temperature, although I
would not use a light oil in the summertime if you're going to heavily
tax the car- I saw oil temps of 150C at Summit Point a few years ago
in 98F weather. That was scary. If I kept the 200 and continued to do
a lot of track events, I would have installed a much larger and better
oil cooler as well as an Accusump.

Taka
looking for a new track capable beater car