fsi owners - super unleaded, do you ??

bovril

bovril

Member
although i have been around the a2oc forum for years i have never read that the fsi engine should be fed super unleaded, but i just read this in another thread...

..."just remember to run it on super unleaded--tescos/sainsburys both do them as well as the premium brands IE shell/esso.the fsi technology in your car needs the higher octane rating to give best performance and fuel economy"!

tell me more please !
 
I dont have an FSI myself but I think that the fsi's need higher octane fuel to run properly to deliver its best possible performance/fuel economy.

My 1.4 petrol always runs better on shell vpower too.. its all I feed her :)
 
Hi bovril guilty as charged sir it was me---and i think i am correct in that statement. as far as i am aware the fsi injection system when in operation IE sub 3k and small throttle openings produces high volumes of nox so that the egr valve is in operation to help purge this gas out along with the nox cat in the exhaust. the higher octane fuel helps to lessen the output of nox so that the egr valve doesn't open quite so often spoiling the performance and economy.
i have only ever run on normal unleaded the one tank and could feel a difference in the economy and smoothness of the engine. there is also a decal in the fuel filler cover that specifies the use of higher grade fuel.
hope this helps give it a go and see if you see a difference cheers Mike
 
I think its all a conspiracy by the petrol consortiums cos super unleaded is more expensive...

Reckon you should fill up with regular and bung in the additive that boosts the octane... Either that or buy a diesel... ya know it makes sense!!!:D:D:D
 
I always put super in mine...when i have used regular i always felt there was a difference in the smoothness of the engine. I heard somewhere that they re-jigged the ecu in the fsi after a while so that it could run on regular but i've no idea if this is true?
 
Does it not say on the inside of the petrol flap or the manual what it should be?



Cheers

Sarge
 
bovril said:
although i have been around the a2oc forum for years i have never read that the fsi engine should be fed super unleaded, but i just read this in another thread...

..."just remember to run it on super unleaded--tescos/sainsburys both do them as well as the premium brands IE shell/esso.the fsi technology in your car needs the higher octane rating to give best performance and fuel economy"!

tell me more please !
Click to expand...

Hi bovril

According to the brochures the 1.6 FSI engine is optimised to run on 98 RON petrol but will run on anything down to 91 RON. As I understand it, the engine is fitted with knock sensors which detect the small engine vibrations caused by pre-ignition under certain load conditions when using lower grade fuel. The ECU then retards the ignition timing to prevent the harmful pre-ignition and this reduces the performance while still allowing the engine to run smoothly.

Cheers Spike
 
I've had my FSI since Jul 2003 - and have only once put a tank of super in - it was around the time that the coil packs gave up the ghost (back in '05 I think). I found switching fuels to cause more confusion to the ECU - lumpy ride etc - so have not used super in it since. Still get 45mpg on average - which I happy enough with.

And as others will testify - performance has never been top of my desires (having been one of the few members to have had their A2s de-mapped to factory settings). I'm happy with how my A2 performs in stock form.

Ben
 
Only Super for our FSi

I dreaded driving my wifes FSi until I read on here to use V-Power
since the switch I love driving the car, gone is the stutter and erratic performance, here is a smooth and quick pick up

I know much of this is opinion but our car has a new lease of life thanks to super unleaded
 
the guru said:
...Reckon you should fill up with regular and bung in the additive that boosts the octane... Either that or buy a diesel... ya know it makes sense!!!:D:D:D
Click to expand...

Hmmm, no.

As I suspected long ago, with comments from friends who used these so call additives. They do nothing. Which? - the consumer magazine recently did a test on main brand additives. Their lab result showed NONE of the additives made any significant change in octane/cetane for petrol/diesel. Their conclusion is none of the additives do anything that changes mpg or power. Are these the same as fuel line magnets or electric superchargers on ebay? I'll let you draw your own conclusion.

On the other hand the magazine also tested standard vs premium fuels a while back, the measured octane content matched what every brand, including supermarkets, claims on their 95/99. It is most definitely not the same placebo effect used in branded, expensive Super Fast paracetamol (do you also think branded stuff works better than standard 500mg supermarket label pills?). And the premium fuel experiment has been done by many people, using their own car on the same rolling road. I can testify the obvious difference of 99 vs 95, but I've yet to try the BP 102 ;-)
 
I run a TDI A2 and a petrol MX-5. Fuel quality seems to affect how both run.

In the petrol MX-5 it is considerably smoother and has better low down pick-up with Shell V-Power, than with standard 95 RON unleaded. Tesco super-unleaded (also 99 RON) is not quite as good (as V-Power), and tends to make the car sound a bit waspish, maybe it needs more air via a big induction kit :D ?? But overall it runs best on V-Power.

With the A2 diesel it really likes having Millers Diesel Power 4 added to every tank. It is quieter (a nicer rattle!), picks up better from low revs and is smoother once warm. You can tell if I haven't put any in!

Some of this maybe a placebo effect, but with the MX-5 I doubt this. With the A2 perhaps?, but a little fuel additive doesn't cost much so I will continue to use it.

Cheers,

David
 
I don't like the cost of V-Power, but my 1.4 has been fed 98 for the last three-four years.

It's had the throttle body cleaned twice in that time and now I calibrated it properly it is running very nicely indeed.

Bret
 
so should i change now after 5 years of std unleaded ?

A2 Golden Miler said:
I dreaded driving my wifes FSi until I read on here to use V-Power
since the switch I love driving the car, gone is the stutter and erratic performance, here is a smooth and quick pick up

I know much of this is opinion but our car has a new lease of life thanks to super unleaded
Click to expand...

The question now is ...

Should i change now after 5 years of standard unleaded ?

will it bring on new faults, the coil packs have been done in the last 6 months b ut i could do without any new faults, that said the car is currently feels a bit sluggish.
 
Can't comment on the FSI but pretty much everyone I spoke to, from driving a 2 troke Vespa (my old toy) to 2.0L turbos all agree V-power makes a differences. Other drivers I know with big engines only ever feed 98RON. I often switch between standard unlead and v-power depending on price/planned trips.

I've had a single incident after I filled up Tesco 99 and engine management light came on, complaining too lean. Restart the car and it was fine, although the fault code was logged. I've since cleared the code and switched between V-power/Tesco 99 and standard shell/tesco and the fault code never came back. FSI could be more sensitive but thought I would share my experience in case you see the dreaded engine management light!
 
I might be of some help here, I have a 02 FSi and bought it nearly 2 years ago and ran it on normal Enron 95 petrol (normal unleaded) until it started to feel really unresponsive and juddered. So in it went to Audi as it was due for service and they told me only to use Enron 98 petrol (super unleaded) in the engine because the engine builds up Carbon deposits and can need the throttle body cleaned on the Enron 95 petrol (normal unleaded). I asked if this really makes any difference and I was reassured that it was by an articulate and informative Audi technician. Basically I have a low mileage car and using Enron 98 petrol (super unleaded) has made a difference. I'm not one to say I have figures to prove it, but the computer is up by 2mpg and I have noticed a increase in power. Okay it's a couple of pence per liter more but a cool website is http://www.petrolprices.com to find the best price for your motion lotion.

On another note, I put Shell V-power in my fireblade to see if it made any difference to performance and my god it has! Its still lightening quick but the power up and down the revs is so so smooth! so on the next fill up I am going to try Shell V-power in the A2 I will report any results.
 
As I understand, FSI is direct injection, so the fuel goes into the combustion chamber separate from the air; unlike my non FSI petrol car. So the detergent in the premium petrol can only clean the high pressure fuel injectors. It shouldn't clean the throttle body as the fuel is not mixed at that point. I don't own an FSI engine, but this is what my 2.0TFSI engine friends told me which seems logical enough (as well as how audi demonstrates FSI on their website). May be this articulate and informative Audi technician knows more?
 
I thought that humps,My Mitsubishi was a GDI,gasoline direct injection and sure enough had to have its throttle body cleaned twice in its 45,000 miles life.
Car was ditched as they have had some in with Heads needing a decoke,oohh remember those days!:p
I got an old corrado that can run on 95 but runs far sweeter on 100 octane
 
humps said:
As I understand, FSI is direct injection, so the fuel goes into the combustion chamber separate from the air; unlike my non FSI petrol car. So the detergent in the premium petrol can only clean the high pressure fuel injectors. It shouldn't clean the throttle body as the fuel is not mixed at that point.
Click to expand...

I agree with your summary Humps. I have not seen any schematics for the petrol engines but suspect throttle body contamination is caused by the engine breather system recirculating blowby gases and oil mist back into the air intake.

Cheers Spike
 
Sounds like this is getting complex, I'm no engineer but I think I can just about grasp that the more carbon and less (if any?) detergent there is in the cheaper fuel, would mean that on ignition there would be more chance for the hot gas to stick to surrounding material causing a build up and thus effect performance of parts and engine? Guys, I am I on the right track? or WILDLY off course? (Just like my golf game)
 
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