What oil to use?

[Tom66]

I need to top up the oil in my 97 a4 1.9Tdi quattro saloon, i have some 10/40 semi synthetic and some 15/40 semi synthetic. What would be the best to use? I looked on the service bills and it just says semi synthetic with no mention of grade.

[PetrolDave]

Check the manual in your car what the VAG spec that the oil has to meet - then go into Halfords and read the labels.

I use Castrol Edge in my RS4 - one of the few oils that meets the VAG specs required.

[Tobes49]

Either will be fine, As long as they are a Quality oil, not this £5 a gallon stuff.

[JamieSelway]

Not that I'm going to do it, but...

I had Audi Assistance out last week, and while the guy was there I asked about oil, as I need to get a bit to keep for top ups.

He told me as long as it meets the "VW 504 00/506 00" or the latter "VW 504 00/507 00" specification, it should be fine. In fact he uses a "VW 504 00/506 00" spec oil made by Coopers(?) in his 2.0. Which he rekons costs £8 a gallon

(You'll have to check your own viscosity of course!)

Now I know you'll all start gunning for me, but he had a sheet in the van from Audi listing all makes that met the standard, so I figure it's probably kosher. My own reasoning behind not using that oil is that my baby went to a main dealer for service, and I want to maintain the same make of oil between oil changes, so I'll have to get some Castrol. If I was changing my own oil, I'd probably use something different (I've found Miller's reasonable in the past)