oggie_s

can I mix 5W30 with 15W50 both Mobil 1...

thanks for the answer...

PS Do S4s come with synthetic oil from the factory or not... Is it a good idea to put synthetic oil in at 4000 kms???<p>Oggie S.

Innovator

That should be no problem.

Rich Martin

From what I've heard (I'm no expert), mixing it should be fine. However, Audi is now apparently using Mobil 1 0w30 from the factory.

Rich
'01 nogaro

Just a stock S4

Mixing gives you a blend that has intermediate characteristics. e.g.: 10-30 + 20-40 yeilds 15-35.

But! The two have many other differences. Wider range oils (5-50 for example) require viscosity extenders, which are not a great thing. Narrower ranges, so long as they are wide enough to cover your application, are more stable long term.

Until this year, audis came with (so most seem to say) 5W40, non-detergent, dino break-in oil, that should be left for at least 4k miles, maybe more.

New ones come with 0W30, which to my knowledge, is only PRESUMED to be Mobil1. Since I'vce personally experienced delayed audi ring seating using M1 too early, I have trouble believeing this. unless they also switched to pre-ship break-in. A costly process. Maybe they did. Proof anyone?

In the long run, synthetic is a very good idea to sustain the turbo bearing temperatures and protect your turbos. If one fails you (1) replace them both, and (2) remove the engine. not in that order :-)

Grant

nubS4

The vis will always revert to the lower number when mixing.