All UK fuels should be ok for 1.6 FSI in Jan 2009!

N

N00N00

Member
People might be interested to know tha an FSI Audi is designed to run on low sulphur or sulphur free fuel.

I've researched this fairly thoroughly - originally only opimax had a low sulpur level, but I've just noticed that all super unleaded type fuels in the uk became low sulphur in Dec 2007.

Also, in January 2009 apparently ALL UK fuels become less than 10ppm sulpur, so that might represent a big saving for everyone having to buy Optimax right now.

So in summary if as a 16. FSI driver you've been using just Optimax for years you can now try other brand of super unleaded and they should now do the job. Also, in January you can put the cheapest fuel you can find in the tank as that want clog up the engine anymore!

here's an article confirming everything:

http://www.ukpia.com/industry_issues/fuels/sulphur_free_petrol_and_diesel.aspx

Hope that should save people a few quid.
 
I was told that the A2 was designed to run on high octane fuel, sulpher was never mentioned and when I tried the normal 95 octane variety the engine misfired slightly under most loads and in normal running. Are you telling the forum that this is not the case? If we can use normal 95 grade petrol, of course from a fuel cost point it would be great.
 
I had to run my mitsubishi on Super due to sulpher probs in Uk petrol.
However,most of the gdi engines still need a Decoke if not using optimax
 
From what I've read 95 ROn should be fine - sulphur is the main issue. However, I supposed higher octane may still be better.

Certainly one significant point to bear in mind is that other super unleaded fuels are now the same as Optimax in terms of sulphur content so you can save money by shopping around etc just on super unleaded.

We'll have to see what happens in January but FSIs are designed to work with 95 RON. I expect that Audi have always recommended Optimax in the past because it was the only fuel with the lowest sulphur content, yet most people were (wrongly) assuming it was because it was high octane fuel.

So just to remind people with an FSI engine you can now buy any SUPER unleaded in 2008, then any unleaded of any type in 2009.

The fuels were supposed to have been introduced 5 years ago or so, so seems a shame everyone has had to spend so much money in the mean time.
 
Chubby - have you tried super unleaded this year - remember it is only since Dec 2007 that the sulphur levels went down on other brands of super unleaded (and perhaps there was a bit of crap left in the tanks for a while after that too!)
 
I bought the car new in 2001,
sold it to get the A2 and heavy deposits were found in the throttle body
EEK!

damage was already done the previous years,
as she had a habit of goign to Tescos the fuel that has no additive.

With regard to the A2 I use millers diesel additive and hope it does its wonders.
 
Mark Brigg said:
I was told that the A2 was designed to run on high octane fuel, sulpher was never mentioned and when I tried the normal 95 octane variety the engine misfired slightly under most loads and in normal running. Are you telling the forum that this is not the case? If we can use normal 95 grade petrol, of course from a fuel cost point it would be great.
Click to expand...

The 2003 Audi 'A2 Details' brochure quotes the 1.4 engine requires 95 RON fuel but specifies 98 RON for the 1.6 FSI with the following rider
'' The use of super unleaded (98RON) is recommended. 95RON can be used with minimal reduction in performance and no adverse effects''

Cheers Spike
 
Thank's, Spike.

I have used the supermarket high octane varieties for a couple of years now without problems. In fact my A2 is driving really nicely at the moment. Tesco's 99 stuff is always OK, the only thing I ever buy from Tesco! Sainsbury's is just as good and at 103p per litre last fill is a bargain! Ouch!

Gubbined up throttle bodies is always an issue, though. I always get mine cleaned fairly regularly.
 
chubbybrown said:
Spike it would retard the timing to avoid pinking?
Click to expand...

I'd agree. My understanding is the engine knock sensor (often wrongly confused with the emissions related NOX sensor) detects minute vibrations caused by pre-ignition and changes the timing accordingly.

Cheers Spike
 
Another thought,

The original FSi engines were design to run lean, ie. less fuel than air, for better econmy, and since the only thing left to oxidise in the combustion cylinder was nitrogen, they produced a lot of NOx. A catalyst system was designed to store the NOx in lean running periods and reduce it (NOX --> N2) when there was sufficent fuel. The catalyst system was especially sensitive to sulfur, hence the recommendation that all FSi engfines (that were mapped to run lean) should use sulfur free petrol. The 0ppm S fuel has been available in Germany for many years. The only FSI engine, that I know of, that ran lean was the 2.0FSI fitted to the A4 in around 2001/2002. Latter in production it was quickly re mapped to run lambda 1 (equal fuel and air mix) once the problems with fuel purity were identified (~2003). I am not sure whether the 1.6FSI ever ran lean??

In my experience cars are very sensitive to fuel type and quality, I only ever use Shell diesel in my A2, and V-Power s-unleaded in my MX-5. So far no mis-fire problems, and good performance and economy seen.

Cheers,

David
 
spike said:
I'd agree. My understanding is the engine knock sensor (often wrongly confused with the emissions related NOX sensor) detects minute vibrations caused by pre-ignition and changes the timing accordingly.

Cheers Spike
Click to expand...

Quite right - there's a couple of knock sensors (actually microphones) that listen to the combustion chambers for any tell-tale sounds of pre-ignition (pinking) and the ECU adjusts retards timing accordingly.

When I got my 03reg A4 V6 re-mapped by Mihnea at MRC a few years ago (live on the road re-map), I had Tesco 99 in there but the standard mapping was still retarding ignition >4500rpm - we managed to re-map with 6degrees more advance on the ignition, which was a lot more power at the top end.
 
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