cnair

I did STFA on this and I found recommended weights ranging from 0w-30 to 15w-50 for synthetic oil. I am switching to synthetic for the first time (2000 A6 2.7T, 24000 miles)and the dealer recommended 15w-50 MOBIL 1, which sounds too heavy. What oil weight would you guys recommend for synthetic oil.

TIA

Silver 2.7tt

condition is S. Cali. If you live in a colder climate maybe something not as thick

TXurS6

My 2001 manual says 0W or 5W. Can't remember if the 2000 manual states something else. Try a search. You're sure to get a lot of hits if you type in "recommended oil".

TraderAlex

On a related subject, my local shop pulls the oil out of the pan through evacuation, rather than letting it drain out through the plug. They insist this method not only effective, but better than letting the oil drain out through the bottom.
What do some folks think, here?

ar2002

It's not as effective; the slope of the pan is designed to drain all the oil & dirt.

ar2002

...to assure proper lubrication on startup. A good fully-synthetic oil in 0W30, 0W40, 5W30 is recommended by Audi, and I concur. The 0W40 weight is best, especially for engines that have higher miles on them or that see harder usage (severe service). I think that 10Wx, 15Wx, and xW50 oils are all too heavy for the A6 engines. I'd pay attention to what the manual says, not your dealer who happened to get a good deal last week from Castrol.

ar2002

...say, the "40" in 0w40. And in that case one should at most go only one grade higher than the recommended weight. The engine cooling systems are designed to always operate within a specific range regardless of temperature and even lighter 30w oils are designed to not break down at higher temperatures - especially fully-synthetic oils. Lighter oils provide more cooling capability than heavier oils, too.

chairman

0W 40 for the next change to carry me thru the summer. I want to see if it runs cooler. I have 18k on the car now.

6sidua

to help meet higher mileage standards for the entire car line. 0w and 5w improve mileage by 1-3 mpg over 10w or 15w oils. most new engines from all makers now spec these weights for this reason alone...
it's a common misconception that better machined parts with tighter tolerances require these lower weights. this is auto fiction...

lower viscosity does improve flow during cold start up (0 to -10degrees) but 0w oil is all about reaching mpg standards. if your car lives in the artic a block heater is a better way to deal with this issue.

30-40w is also all that's needed on the high end, unless the engine operates at very high temps-like a rotary engine. some forced air devices increase temp too, but that's not the primary reason for audi turbo failures.

5-30 or 10-30 offers complete lubrication, cooling and sealing. if one uses higher viscosity >40w), it may add to heat production in the audi engines. of course the oil does break down so 10-40 becomes 5-35 over a 7-10k driving interval. older worn engines tolerate 40-50w better but that doesn't mean higer viscosity oils help these engines-more auto legend.
5-30, 0-30, 10-30 are all the same for daily driving or even tracking periodically. ymmv
cheers

allroad'Ed now

Keep in mind that the factory is assuming dino oil (real petroleum stuff) as opposed to synthetic. Petroleum products, when cold, do not flow well which drastically effects both initial fuel economy and more importantly emissions on a cold engine. Part of emissions certification is output on cold start. 0W and 5W oils offset that problem.

But good synthetics flow significantly better when cold than dino. So it is not unreasonable to conclude that when using a synthetic we can move from a 0W30 to 5W (or even 10W in especially hot climates.)

As point of reference, I played with my 911 at the track one weekend. Air temp was close to 90 all day, with track surface at 110 on my pyrometer.
Started day with 20W50 Castrol GTX and my oil temp after a 30 minute stint on the track ran dangerously close to 250 degrees.
Switched to Mobil 1 15W50 and the temp went down to 220. Switched to Mobil 1 10W40 and temp stayed at 220-225 but car felt like it picked up a bit of response in the 5000-7500 rpm range though that could be just wishful thinking.
Bottom line- the thinner Mobil 1 offered better protection than the heavier petroleum. And on cold startup, I had pressure sooner. I have run 10W40 in it ever since.