RKA

I just realized this, this morning. Up until recently I've been running on 0W30 Amsoil series 2000. It's fine, but when the temps drop below 50F, cold weather starts are accompanied by a loud siren song. This gets progressively louder as outside temps drop to 20F, and from 20F and below, it doesn't seem to get any worse, as it's already plain loud. In all cases, eventually it subsides to the normal siren song when the oil temp comes up to normal.

Frankly, I assumed this was normal, until I had an A6 2.7T loaner, which was DEAD quiet! That left me wondering. I've also driven in PAJohn's car...also pretty quiet...and he's got 100K miles more than I do on his car!

Okay, so a month ago I switch to the german made (not made in the good old US of A) Castrol 0W30, and it just occurred to me this morning, the turbos are quiet! Temps have been down near zero overnight, and sure, the turbos sing a little when I start the car and take off, but nothing like they were before. Oil temp takes about the same amount of time to come up to normal, and after the oil is warm, the castrol seems to still be quieter, but I wouldn't bet any money on that statement (in other words, it's negligible).

Oh, it goes without saying...NO BOOST in either cases until oil temp comes up.

If anybody can explain this, I'm all ears. I haven't poured through the specs on each oil, and even when I do, I don't expect to find anything of significance in the published specs.

DAP@EPL

Interesting. Where is the German Castrol sold?

ryans4

...on the back it'll say Made in Germany. It's 0w30, and I think it's full IV synthetic, no III mixed in (could be wrong there).

I'm trying it next. I paid $54 including tax for 12 quarts.

DAP@EPL

Not bad at all... might have to give it a shot. Any specs vs Mobil1 0w40?

ryans4

...I ran Mobil 1 0w30 on my first oil change, I hated it.

I'm going to try Mobil 1 Delvac 5w40 after I run the German Castrol 0w30 for 10k miles. Then I'm going to try the Shell Helix 5w40 for 10k after the Delvac.

Then I'm going to compare the following(blackstone):

Castrol TWS 10w60
Castrol 0w30 (German)
Mobil 1 Delvac 5w40
Shell Helix 5w40

I may through some Redline 5w30 back in and sample that as well since I used to run it for 50k miles, I switched to the Castrol TWS cuase oil temps on track were too high. But now with the Oil Cooler, I'm going to go lighter. My only fear with the German Castrol 0w30 is that it's going to be too light even with the oil cooler for track driving in Las Vegas.

DAP@EPL

Cool. Keep us updated with your results.

reefer_bob

I'll stick with my other oil.

ryans4

at 10k per oil, 3 oils, I'm guessing in about a year.

I may just run them for 5k each, but I don't think that's fair to the oil. I think two changes is a good sample.

But for sure I'll post the results...

ryans4

mine did that as well, and the valve clack was annoying..

FixedWing

I plan on using German Castrol 0W-30 for the dead of the winter here in Connecticut but after I will switch back to Mobil 1 0W-40 for the summer months. I only occasionally see about 200F in the winter but regularly can see 250F in the summer. So I think 30 weight makes sense for winter but I just feel more comfortable with the 40 weight in the summer.

Both oils should be group IV oils.

I guess you are going to the 30 weight to get more power? Makes sense to me also.

Stephen