Castrol SLX Vs. Mobil 1

[Riz_RS4]

After recently having my S3 serviced they have now put my car on a different oil.
[img]images/rsul/21237-oils.jpg[/img]
Before:
Castrol Formula SLX 0W-30
Approved, VW 502 00/505 00 (01/97) & 503 01 (01/99)

Now:
Mobil 1 0W-40
Approved, VW 502 00/505 00 (01/97) & 503 01 (09/99)*

*Note that the Mobil 1 oil has got a new date, what does this mean? Does it mean that VW has tested this later and it performs more better than the SLX oil?

Also the old oil was 0W-30 but the new oil is 0W-40, does this mean that the Mobil 1 stuff is better? Will i notice the difference?

Also since they have put this oil in, its more likely i can buy more from halfords and not get charged loads by the dealer`s! yippe!

Cheers [img]images/graemlins/beerchug.gif[/img]

[Paul-RS]

Castrol is supplied from factory in both my S3's

so i have carried on using it.

on AVS it's VW 503.01 spec you need. ONLY

[DuncS3]

and the Castrol bottle looks better!

[Riz_RS4]

Yes i was using Castrol from factory too until they changed it at the dealers..... this new Mobil 1 does work with AVS otherwise they have messed up at the dealers [img]images/graemlins/033102bad_1_prv.gif[/img]
What difference is 0W-30 Vs. 0W-40?

[sitas3]

What difference is 0W-30 Vs. 0W-40?

oil viscosity, or in my world, thickness!!

[Riz_RS4]

Mmmmmm so nothing to worry about then?
Ive now tripple checked the service manual and the back of the mobil 1 bottle and all is ok for AVS.

Cheers

[Dippy]

Castrol is supplied from factory in both my S3's

so i have carried on using it.

on AVS it's VW 503.01 spec you need. ONLY

Not quite correct. For the S3 you must use 503.01 oil no matter what your service interval. It's only the S4 which can use non-503.01 oil if AVS is not chosen.

I'm guessing, but the later date on the Mobil 1 means that it was approved to that standard later than the Castrol was.

The '40' does refer to viscosity, at operating temperature. It means that it's thicker than the Castrol when hot. This is a bit better if you run your engine harder than average. I also find that Mobil 1 gets a bit hotter than Castrol anyway.

[Riz_RS4]

Cheers [img]images/graemlins/beerchug.gif[/img]

[Paul-RS]

Castrol is supplied from factory in both my S3's

so i have carried on using it.

on AVS it's VW 503.01 spec you need. ONLY

Not quite correct. For the S3 you must use 503.01 oil no matter what your service interval. It's only the S4 which can use non-503.01 oil if AVS is not chosen.

I'm guessing, but the later date on the Mobil 1 means that it was approved to that standard later than the Castrol was.

The '40' does refer to viscosity, at operating temperature. It means that it's thicker than the Castrol when hot. This is a bit better if you run your engine harder than average. I also find that Mobil 1 gets a bit hotter than Castrol anyway.

Dippy. From Manual.. page 203 "Engine Data"

Engine Oil:

Long Life Service (AVS) VW 503 01 only (they even have it in bold)

Fixed Maintenance intervals VW 500 00, 502 00 or VW 50101

This is from my 2003 S3 manual.

[Dippy]

Maybe Audi changed the rules. There's nothing in the A4/S4 manual, it's in the Audi Service Schedule (covers all models):

"For some specific turbocharged petrol models (154kW Audi S3; 165 kW Audi TT and 280 kW Audi RS4), oil conforming to VW specification 503 01 must always be used"

Since my book predates the 225 Bhp S3, maybe it did change, but why if the 225 Bhp TT is mentioned?

Anyway, IMO anyone with a high boost engine should use a decent oil regardless of service schedule, and such an oil will undoubtedly meet 503.01.

[Paul-RS]

my service book, just says refer to owners manual.