Not sure if this has been asked before but I'm not sure what to do, I have a S3 SEL EXec 1.4 TSI Act (manual), which fuel should I put in, the first fill up was standard petrol but just coming up to refill soon and was thinking of moving to the premium fuel. Does it matter, will it make any difference.

 

The car has only done 400 miles so not run in and I'm not getting great economy out of it yet (~30-35 mpg round town start stop driving) but that could be due to my heavy right foot.

 

Some advice please.

 

What does the sticker inside the fuel flap say?

You can use normal unleaded (95 RON) . You can also use super unleaded like shell v power or BP ultimate (98RON). Modern cars are tested on the premium fuel and they do keep the engine clean . Honest John from the telegraph has been saying this for years.

As for the sticker on the fuel flap if it does not have one like mine did not, a quick call to your dealer and they should get one for you useful if going abroad.

The S3 only requires 95 RON, unlike older generation engines which needed 98+. If it isn't mapped to take advantage of higher octanes then in theory there's not much point. That said, some tests show that even these normal cars can get better economy (about 4 percent) on super, and both VPower and Momentum 99 have several times more detergent than regular equivalents.

Personally if it's leased I'd stick to 95 and reap the low cost. If it's your own car I would perhaps throw in a tank of Super every fourth fill to keep things clean. As the S3 is turbocharged you may well find it still responds well (more power and higher MPG than on 95), as I do wonder whether VAG just changed it to 95 to simplify things for owners. Most wouldn't notice the slightly lower power or MPG and it would help differentiate the marque from its more 'premium' high powered stablemates. Call me cynical.

I am still waiting on my 2.0 220hp (roll on build week 09) so I can't say for sure either way. Just suck it and see, M99 is only £2.50 more a tank than regular 95RON. Do report back please!

Where do people stand on fuel additives in modern cars? Are they good or bad for the engines?

Where do people stand on fuel additives in modern cars? Are they good or bad for the engines?

 

The handbook/manual states that using additives will invalidate the warranty. That said, I personally would trust a good quality additive (catalyst and detergent) such as Millers EcoMax based on prior experience. It works out around 2ppl extra on the fuel base price, but that's quite handy when 95RON is 98ppl and super in your area is 110ppl, for example. Personally though I'd just buy high grade fuel with the additives included and not take the risk. Bear in mind all fuels contain additives anyway, though there is a higher proportion in super (3 or 4 times the amount for VPower and M99).

Thanks for that info, very useful.

The S3 only requires 95 RON, unlike older generation engines which needed 98+. If it isn't mapped to take advantage of higher octanes then in theory there's not much point. That said, some tests show that even these normal cars can get better economy (about 4 percent) on super, and both VPower and Momentum 99 have several times more detergent than regular equivalents.

Personally if it's leased I'd stick to 95 and reap the low cost. If it's your own car I would perhaps throw in a tank of Super every fourth fill to keep things clean. As the S3 is turbocharged you may well find it still responds well (more power and higher MPG than on 95), as I do wonder whether VAG just changed it to 95 to simplify things for owners. Most wouldn't notice the slightly lower power or MPG and it would help differentiate the marque from its more 'premium' high powered stablemates. Call me cynical.

I am still waiting on my 2.0 220hp (roll on build week 09) so I can't say for sure either way. Just suck it and see, M99 is only £2.50 more a tank than regular 95RON. Do report back please!

Well I filled up with the super unleaded from ESSO yesterday and I've done about 120 miles so far a little trip to Derby this morning for a meeting, and I've not noticed any more power but then again im still running her in so not gone over 4000 rpm, but I have noticed the since start economy has improved by 4-5 mpg for a motorway run but I will only know how much better it is when refill the car don't trust the computers they are never that accurate. I also need to taking to account that the car is still running in and I wont probably get a true understanding until I've done a few thousand miles.

 

I own the car, (sort of its paid for by a company car allowance) but I'm planning on keeping it long term, so I like the idea of 1 in 4 tanks being premium/super unleaded.

 

Thanks for your comments.