The base car is a WN engined, 5 cylinder, carburettor series 2 Coupé. Ask Audi or autotraders about the usage of unleaded fuel in older vehicles, and the responses you get may be short of satisfactory. We know that the WN engined models are just ONE that cannot be adjusted easily or cost effectively. (Others include some of the earlier 10 valve Turbo models- check with Audi UK for exact details).

Here’s roughly how it all started, via e-mail……

“……….On the petrol front, I was thinking about putting something on the website, for companies that want to send us/ you samples, and for other people that are interested in your findings- a link to your e-mail address, perhaps? This is entirely upto you. On the subject of petrol, Oliver’s car, understandably, needs 98 RON fuel. The services at Tamworth do this, I checked on Saturday night when I filled up. We called last night to fill up, Oliver quite relieved to find that we sourced some- the bloody things were empty! Shit a brick time, because he had never run the car on 95 RON petrol, and we didn’t know if the modified ECU could alter the knock sensors to cope. Thankfully it did, but at a cost- the car constantly runs at 1 BAR boost pressure. This dropped to 0.6 Bar, and my tarmac terrorist was leaving him! :-))))”

(Andy Bowskill- note the part about Oliver’s 1.8T engine and standard unleaded!- A3/ A4/ A6/ TT owners take note!)

Below are all the reports/ findings sent in by Rob to date. Any questions/ comments can be addressed to either him, or us here in the office. If any company would like to send samples to us for trial in this article, please do not hesitate to contact us. We would also like to know which companies are represented on the web that sell Super Plus unleaded here in the UK, and if they have a complete list of addresses of the petrol stations that stock it.

28 October 1999 18:52

Hi Andy, After taking your advice I spoke to the Audi Customer services regarding the uniqueness of the WN engine that sits in the early Coupé’s. The first person I spoke too was very friendly and when I mentioned that the car seemed to run badly he commented that his car (what ever it may be, was also running poorly and he was going make some enquires and phone me back. He did comment that my Coupé must be one of the first! The day passed and I had no return call. I phones on the second day, explained that someone was supposed to call be back, they took the details and said that someone would call me back, guess what, no returned call. On the third I phoned again, to be told that this is a technical enquiry and you should go to your local dealer. I asked why I had not be told this before? the reply being well you should have, I slammed the phone down in disgust. So I have purchased some Castrol Valvemaster plus which boost octane so I can put unleaded in with a splash of this. It works out at 4p per litre which makes it cheaper to buy unleaded and add this then it does to put 4 star in (if I can find any). So there you have it my car has now become a live test. I know the official line from Audi when I spoke to my dealer was they all take super unleaded from 76 onwards, but when I said that the WN engine was a high octane and should it be any different there was silence. So it seems that they just don’t know, or want to get you into the dealers to get money off you. From looking at the e-mails from people in the discussion group it seems that a large number of Audi dealers do not come up to the standards of their cars. On a similar vain I know of an Audi garage that puts unleaded in their demonstrator TT when the spec says 98 octane, when I asked the sales man he said ‘it seems alright’. DO you think they have realised that super unleaded is like Rocking Horse S*$£ (well it is round my way) and they seem to have a number in the current range that need it! I will let you know how my car gets on with the additive. Castrol has a web site (but I haven’t looked at it yet)

Rob member 278

08 November 1999 22:15

The dilemma of an Audi Coupé GT5S (and the rest!!!) With the recent changes in fuel a number of motorist have been left in the lurch by the government, the fuel companies and the car manufacturers. 4 star is now a thing of the past, most garages have switched to LRP with little or no warning, the staff don’t really understand why, and if you ask where can I get proper 4 star they come out with the standard line ‘LRP is the same’, they seem surprised when you say it isn’t and ask where can you get some “proper” fuel and they say the Government has banned it. (we should still be able to buy it in small quantities – but where?) They obviously do not have clue as to what they are talking about (sorry if I have offended anyone but it is what’s happened to me). As you may know most Audi’s post ’76 can cope with unleaded, but some of the engines require high Octane (98 Ron), this isn’t just limited to a small number of the old engines but it is also the case for most of the current breed of 1.8T engines in the A3’s, A4’s, A6’s and TT. Audi’s official line is put super unleaded in, which is fair enough but there is not much of it about, the example of Oliver’s mega Audi 80 which lives and breathes 98 octane had an availability problem which resulted in a reduction of performance. In enquiring further assistance from Audi I have contacted the Audi customer care line only to be told see your dealer, my dealer confirmed the statement that they all run on super unleaded but when challenged about my specific engine (WN) they don’t know, and also when challenged about the availability of Super unleaded I have been told by another Audi dealer that normal unleaded goes into all there cars including the TT demonstrator! (and they should all run on super – Hmmm) In theory all of this should not hurt the engine, it should only degrade the performance. In theory the Audi engines are tough enough to not suffer from any VSR (Valve Seat Recession), but no one has compared performance and derivability with the different fuels and additives. I will be trying the different additives and fuels in my Coupé over the next couple of months. My Coupé covers between 40- 700 miles per week as I use it for work. I will give my impression of how I think the car behaves with the different additives.

The test Vehicle Audi Coupé GT5S 5 cylinder 1921CC WN Engine, First registered in 1981. Current indicated mileage is 58,000 but this is out since the trip meter sticks thus stopping the main counter! The real estimate would be around the 130-150K. Engine modifications none (But I am thinking about it!). So far the car has run on 4 star, LRP, Unleaded and unleaded with Castrol Valvemaster plus. Other additives will be tried in due course. If anybody else has a view on this please let me know, also if Audi UK want me to try on a 1.8T engine just park a TT outside my house and I will give it a go!

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