Audifan1

a good choice? I run 10W30 Synthetic now from Mobil and have no issues. My mechanic recommended that I stick with Mobil 1 Synthetic and use the 5W30.
What do you Audi fans think?

By the way my car is a 2000 A6 2.7t

SloopJohnB@mac.com

And like most turbo/engines, when you start it up at -40F let it stabilize for maybe 30 seconds before taking off moderately to ensure the turbos are oiled. Letting the engine warm up for 20 minutes is bad news...it will warm up faster if you drive it.

At -40F or colder things get funny...like tires can crack, ebrake cables stick (don't leave your ebrake on when you park it outside if you can help it), drive slowly around 5-10 mph for first couple miles until the shock oil heats up and bushings warm.

But I don't see a heckuva lot of diffo between 10W and 5W as long as you're within Audi's viscosity range for the temps you're going to see. If the car is garaged, don't worry about it.

FWIW, I've run Amsoil 15W45 marine/diesel oil (certified for use in spark ignition marine engines and diesels) because of the anticorrosion additive package. Been using it on various turbo cars since 1981 (Datsun 280ZX, saab 900T, volvo 740T and 760T, Audi 4.2A6) in temps as low as -40 (Killington or Seven Springs, PA) with no ill effects.
Fair disclosure: Lifetime Amsoil dealer.

Egil A64.2s - S6

Good advise.

Audifan1

that's why I was kind of concearned.

Your post cleared a lot of my concearns. I warm my car 'till the air pump shuts off and than I usually take off (~1 or 2 minutes after I start the engine).

I drive it a little faster than 5-10 mph but I go easy on it. No revs past like 2k rpm.

SloopJohnB thanks for the response.

Just Me

"good to" sounds awfully black and white, which viscosity is not. If we go purely by manufacturer's specs, 10W30 is not good at cold temps. Audi specifies 5W30 or 5W40 for most apps, although on some cards they recomend 0W30.

Regardless, thinner oils flow better at lower temperatures. SAE has a set of kinematic viscosity curves and specifications that must be met.

Bottom line is that if you use Mobil 1 0W40 you are good from the coldest reasonable temsp to the hottest. For most cars, in most non-competitive situations, the 5W30 is nearly as good; mostly failing at HTHS shear, which is abut 10% below the ACEA A3 cutoff of 3.3 cst.

So i cant really agree that 10W30 is a good choice at -40F. Or even that a car should be driven at -40F. But for most normal conditions M1 0W40 or 5W30 are very good choices.

As usual, if anyone wants the actual specs in a spreadsheet, you can email me.

Will a good synthetic 10W30 probably work? Yes. Is it ideal in extreme cold? On a car that specifies slightly thinner oil? I can't see any factual reason why.

G

A6Bman

Good explanation

98Quattro

go with Mobil 1 Synthetic 0W-40.

S4_Cinci (I S'edTFA)

engines. 0w-40 is the best choice (or the Syntec German made 0w-30 that has the VW502/505 approval). Also, 0w-30 or 5w-30 or 5w-40 would all be better choices than 10w-30. They really shouldn't even sell the 10w-30 stuff, but older GM cars call for it, so that is the ONLY reason why it is sold. The only thing that 10w-30 has going for it is a lower level of viscosity modifiers since it only has to bridge 20 points, but I would never use this oil in any German car.

SloopJohnB@mac.com

can be ambiguous for synthetics. ACEA is good to follow, your owner's manual gives you the proper viscosity for your car relative to the temperatures it is operated at.

One just has to go to the spec sheets for the specific oil/manufacturer and car manufacturer involved.

As JM explained, the 0W-40 has a lot more VII added to it (it's basically a 0-wt oil and needs the VII to get to 40). As a synthetic, it may test at 0 and essentially it's a base 15 or 20 synthetic.

txag_a6

that you folks north of the Mason-Dixon line do. The Volvo's owner's manual tells me 10W30 is approved for the 2.5L t/c engine, by the way. I put the same oil in my 3.0L A6, too.