Hi slowlane,
Sorry I haven't been around to answer your questions over in the "0W-40 abuse" thread. (Darn work keeps getting in the way of my goofing off!
![[SPAZ!]](/forums/graemlins/spaz.gif)
)
I don't know anything about the MB engines, so I don't know how much help I can be. My first thought was, "Well, what did the compression measure
on this engine when it was new?" Knowing what the compression is
right now is good, but we really need to know how it compares to
what it actually was back then. (
Not what the manual says it
should have been.)
I agree with what
tom slick said about all the cylinders being very close right now. Maybe paying a mechanic to do only a compression test would give higher or lower numbers than what you came up with? I've also heard that a leakdown test is usually suggested (along with a compression test) to determine engine condition.
My operating conditions may be different from yours, as I run a turbocharged four cylinder engine in a high-altitude climate (typically 15*F winters & 95*F summers). I also run my oil change intervals for 10k miles, so the same oil sees all weather conditions. Since this is my wife's car, I don't want her to experience
any cold-weather starting problems. If I lived someplace where it didn't get below freezing, I'd be running the 15W-50 year-round.
I used to use Castrol exclusively, but their marketing practices convinced me to try something else. Due to this, I've discovered much better results with M1's 15W-50 (in my car) than with Castrol's 5W-50 or 10W-30 Syntec. The car runs & idles quieter (which I expected), & gas mileage is the same (which was unexpected). Switching my wife's turbo over from 10W-30 Syntec to 0W-40 Mobil 1 saw no differences in engine noise or gas mileage. Oil consumption
might be present with the 0W-40 (it lost no noticeable amount of oil in 10k miles with the 10W-30), but with less than 4k miles on the 0W-40 it's too early to tell.
As for BG-44K, I usually run it every 20k miles just in with the gas. (I can't make any recommendations for dumping it straight in the cylinders like you've been told to do.) Another Saab owner told me it cleared a fuel injector he was about to replace, so it saved him several hundred dollars in repair costs. I think he had about the same number of miles you've got, & he had always used premium gas.
[ June 03, 2003, 05:37 PM: Message edited by: Eiron ]