Oil - Your questions answered - Maybe!

[Conan_the_Librarian]

Uncorroborated advice for the interweb.

Volkswagen Group Oil Specifications and their Applications

VAG Group here

And lots more information here

[ulfilias]

Hi There,

What are the specs for the S8 then....Reading Audipages i seemed to get 5w30 or 5w40 as being about the same ???

Ta,
Lee

Hi there,

I've got a 1998 Audi S8 and I'm looking to get some oil at a good price.

I've read the manual and it looks like I'm looking for 5w-40 oil. There are a range of prices on ebay for this product, plus, I'm not sure if 5w-30 is better.

So, a few questions:


- There is some Exol 5w-40 (25litres) at a very good price on ebay, has anyone had any experience of this oil or know anything about it?

- What oil is best to use? Does anyone think that 5w-30 (or a different type)is any better?

- Is there product that is the recommended choice?

- Is there anywhere to get good oil in bulk at a decent price?


I've read the links on this and other posts, but I'm well aware that you get what you pay for most of the time and I'm conscious £20 more on oil could save £2k on a ruined engine, so I'd value some other opinions.

Thanks all

George (2 weeks into owning my first S8 and the smile hasn't moved!)

[Oli18]

Hi George,

I used to work for Castrol so i'm going to give you a very biased view.

I have seen many tests done on engines using different gradients of oil. There are huge differences between brands even when the viscocity (i.e. 5w-40) is the same.

My advice would be to go for the best. I know you're after a bargain but if you've seen the differences to engine wear that we use to test on with engines running for 300k miles on Castrol and some of its competitors, it worth not going down the cheap road.

Castrol Edge (fully synthetic and sometimes also know as Castrol SLX - same stuff but SLX is no longer a consumer brand) would be my choice. For high mileage cars, i might consider Magnatec (semi-synthetic).

Castrol actually works with VAG and other manufacturers to build an oil optimised for these engines and hence are filled from factory with Castrol.

Mobil 1 would be the only other brand i would consider.

Oliver

Cheers Oli, I appreciate that.

OK, as you know your onions I've got to run this past you, have I got this right:

- 'w' means winter
- 5w-40 means when cold the oil won't thicken past 5 weight oil
- when warm the oil won't thin past 40 weight oil

Is that right? I don't know what the weight oil means but I get the idea.

The recommended oil is 5w-40, what benefits will I get from 5w-30? I presume I won't see these benefits, but what are they?

Less wear on the engine?
Even though the UK isn't 'hot' will the fact that it won't thin past 30 benefit?
Would 5w-20 be even better?

Thanks

George

[r8dream]

hi george,
i've recently been researching my s8's oil problem.(long post) as some who read my posts know i'm going through a litre a month, and have low compression on one bank.
i bought my 2000 s8 from the orginal owner(6 years ago), with full audi history at 80000 miles(it had 20k, 40k and 60k change, long life mobil 1, long life service was started by audi in 2000 model year), then i started using mobil 1, then fuchs and now, castrol edge for 3 years, first 5w30 now 10w60 for the last 6 months, changing every 6-9000 miles, always fully synthetic. the 10w60 to slow the blowby (as it's exactely twice as thick as 0w30).
according to the oil forum, bobistheoilguy.com the best oil in a audi 4.2 v8 engine has finished its useful life by 5000 miles (rs4 v8 fsi testing), fuel dilution was 5% at 10000 miles, not good (fsi prob?).
also according to kolbenschmdt the two main reasons for oil consumption, are long oil change intervals and fuel flooding (leaky injectors or maybe fuel dilution?) so in a nutshell long life service means short life engine.
don't let audi and the other german manufacturers let you think that better oil can last even 12000 miles, forget 20000 miles (long life service), in a high rev modern v8 with an un-coated alumium bore.
my engine problems are common on audi 4.2 v8 cars with 120000 miles.(even though oil usage and compression still within spec. according to audi, it's just a bit down on power). so i believe my low comp. is due to the wear during the first 3 years of my cars life when long life service was used. i also believe my no. 2 spark plug fouling approx. every 3 months is due to an old heilcoil repair and filings entering the cylinder and damaging the surface, or maybe broken oil ring?
the 4.2's use pistons that are iron coated runing in alumium bores (alusil) with no coatings, the cylinder preparation/honing process has only been understood by the majority of engine rebuilders over the last 5 years. i think kolbenschmidt were trying to keep it secret before that.
so the moral of the story is, change oil and filter every 5000 miles, if you want a long lasting engine. john

[Singh]

Ben at AVP really doesn't recommend Mobil 1 in our engines, he uses Quantum IIRC which is VW/Audis own oil.

[Oli18]

Originally Posted by Singh

he uses Quantum IIRC which is VW/Audis own oil.

...which is also made by Castrol!

[A8 3.7]

Hi All,
Personally I've been using Shell Helix Ultra Extra which is a 5w-30 oil it's not cheap but it is cheaper than a new engine. The current mileage is 122,000 the oil is changed every 10,000 or 12 months and uses very little between services. I personally don't like long service intervals especially as the car gets older.

Hope this helps.

[Just_Ben]

Originally Posted by Oli18

...which is also made by Castrol!

Dead right! Only use the best and original oil in my opinion. I have built many engines and found that the original oil has always performaed best. Many other brand's oils tend to tea-leaf as they react with the fuel that gets past the rings during normal operation. This tea-leaf effect causes blockeages in oil ways and even the oil pick up strainers. MASSIVE problem on 1.8T's, RS4's and on RS6's (V8) can cause major turbo failures.

Even Castrol get it wrong though..... the old Long Life 2 SLX (0w 30) wasn't good! But newer Long Life 3 5w 30 is great and I've had NO issues at all. Same can be said of the QUantum (Castrol) SYnta 10w 40 Semi synthetic. I use this in all the older cars and many of the track engines I have built.

Saving a few quid on cheap oil WILL cost you in the long run, just the same with petrol or Diesel! YOu get what you pay for! A few more pounds on oil is worth it to avoid an engine rebuild when your oil pump clocks, wrecking the line bored cam shaft bearings and therefore scrapping the heads!