Which oil?

[Pete.S]

My car's oil warning light came on last night, checked level, still on the last "bulge" of the dipstick, so comforting to know the sensor is accurate and gives plenty of warning.

But for top-ups, which oil should I use? (away from home & haven't got the user manual to hand). B6 uses AVS, and reading other posts on the site some have suggested Audi will use special lubricants. I had a half bottle of Castrol Longlife (0W-30 IIRC, chucked the empty so can't confirm) in the boot so used that...

Would anyone mechanically-minded be so kind as to quickly explain the differences between the different grades (0W 30, 10W 40 etc), and do Audi use a particular brand?

[Mike_K]

My car's oil warning light came on last night, checked level, still on the last "bulge" of the dipstick, so comforting to know the sensor is accurate and gives plenty of warning.

I had this happen in France. Level was off the bottom of dipstick so panicked; eventually the tow-truck/ garage owner (also an amateur rally driver) found me some special Audi-compatible long-life oil and put 2 litres in. After getting home, next day the oil level was way too high, so be cautious and dont overfill. I probably still had some oil "lost" inside the engine when it was topped up.

But for top-ups, which oil should I use? (away from home & haven't got the user manual to hand). B6 uses AVS, and reading other posts on the site some have suggested Audi will use special lubricants. I had a half bottle of Castrol Longlife (0W-30 IIRC, chucked the empty so can't confirm) in the boot so used that...

my manual states that to maintain the long-life service interval I should use a compatible oil, which has a Audi/VW specific code (I can dig the codes out tomorrow and post them; its something like 503/01 and 502/0, but wait till I confirm as there are similar non-valid codes !!). I found these codes on the back of the oil I bought in Halfords. The stealers told me its OK to use up to 1 litre of another oil without invalidating the long-life service interval; any more and it reverts to a standard service interval.

I dont think Audi use 1 manufacturer to supply all oil across Europe. I'd guess that there may even be regional and local variations depending what bulk deals they get. Correct me if Im wrong, but IMHO the key thing is to use compatible oil, and if you have long-life service intervals then probably best to stick with oils that have the required Audi/VW codes.

Im not qualified to advise on the meaning of the oil grades; I do know that one number refers to the oil viscosity, the other is indirectly related to the ambient temperature it can be used in.

[Pete.S]

Thanks Mkrassen.

So it's more important than I thought to use the correct oil to maintain the AVS. Luckily I only stuck in 1/2 litre of the Castrol. If anyone could suggest an oil that can be bought from your typical Halfords/petrol station it would be appreciated. I could ring my stealer but don't fancy being put on hold for an hour while they try & find someone who'd know

[Mike_K]

But for top-ups, which oil should I use? (away from home & haven't got the user manual to hand). B6 uses AVS, and reading other posts on the site some have suggested Audi will use special lubricants. I had a half bottle of Castrol Longlife (0W-30 IIRC, chucked the empty so can't confirm) in the boot so used that...

UPDATED INFO: my manual states that to maintain the long-life service interval I MUST use a compatible oil, which has a Audi/VW specific code. The codes are:

"Long Life Service:
multigrade thin-running oil VW 503 01 or VW503 00

Avoid mixing with other sort of oils. Only under exceptional circumstances can other oil conforming to VW 502 00 be used in limited quantity (up to 0.5l) once only

Fixed Interval Service:
multigrade thin-running oil VW 500 00 or VW 502 00
multigrade oil VW 501 01
multigrade oil ACEA A2 or ACEA A3 in emergency"

-- The spare oil in my boot (purchased from stealer) is Castrol SLX Longlife II, which conforms to VW 503 00, 506 00 and 506 01. Here in Holland, this is also sold in Halfords. Not sure if you have the same product-branding in UK

-- disclaimer ! This info is from a S4 registered in Holland; its conceivable (unlikely ?) that the data in a UK manual may be different, but technically should still be valid.

good luck; Mike

[Pete.S]

Top man Mike, many thanks

[B6S4John]

Castrol SLX Longlife II is the one I use,I bought 4lts from Halfords for £39.99 and top up my 1lt bottle in the boot. When I go to Italy in the summer I'm going to take plenty so I don't have to piss about.

[Pete.S]

UPDATED INFO: my manual states that to maintain the long-life service interval I MUST use a compatible oil, which has a Audi/VW specific code. The codes are:

"Long Life Service:
multigrade thin-running oil VW 503 01 or VW503 00

I've just had to top up again, but I've just spotted something weird: on the back of the SLX II Longlife bottle, it says "Please note you should not use SLX Longlife II if your vehicle handbook specifies VW 503 01"

....but it also says it conforms to VW 503 00. Strange.....