Yes but according to the books and filler flap, the 2.0 FSI (this model at least) actually IS designed for 98, though it will run okay on 95. I've used both and there is no comparison in the "feel" of the car.

If some kind of accurate research found there was no benefit in either perfomance or mpg, I'd still use 99 because it feels like a totally different car.

Using 97 or 99 RON in a car designed for 95/91 operation can reduce performance due to the ignition timing not being optimized to take advantage of the slower burn time of the higher octane fuel and it is also a waste of money.

But why would you use anything other than 95 ron in a car designed to be run on 95?

Using 95 in a car best designed to run on 98 ron does indeed not perform as well. I presume all Octy IIs petrol versions are the same, best to run on 98.

But why would you use anything other than 95 ron in a car designed to be run on 95?

If the other fuels had other additives (extra detergents, etc.) in addition to a higher octane?

Rob.

But why would you use anything other than 95 ron in a car designed to be run on 95?

It is a question people ask and I know some people think it is a good thing to do.

The issue I have with VAG over the need for 98 RON is they are not pointing out to customers that the car should only use 95 RON in exceptional circumstances and it is only too obvious why. After all, when it becomes a problem, the car is out of warranty.

and the only fuels that a fsi can run on seem to be tescos super, vpower and bp ultimate as the other fuels are 97 ron or below.

I doubt if you'd get into trouble using 97, in the normal lifetime of the car [and driver!!] and I do agree that if a car is designed and tuned to run on 95 there is not much point in going higher.

But if the advised spec is 98, and local choice is between 97 and 99, which it seems to be around here, I'd go for 99 every time. Also, it is usually my 99 supplier who is offering 5p a litre off if you shop there, so it is often cheaper than even supermarket 97 elsewhere. Funny old world, isn't it!!!

and the only fuels that a fsi can run on seem to be tescos super, vpower and bp ultimate as the other fuels are 97 ron or below.

I'm pretty sure all petrol cars sold new in the UK must be capable of running on 95 RON unleaded, however, you may find that the quoted figures for the car's performance are captured using higher octane fuels which is why these are advised.

Chris

I doubt if you'd get into trouble using 97, in the normal lifetime of the car [and driver!!] and I do agree that if a car is designed and tuned to run on 95 there is not much point in going higher.

But if the advised spec is 98, and local choice is between 97 and 99, which it seems to be around here, I'd go for 99 every time. Also, it is usually my 99 supplier who is offering 5p a litre off if you shop there, so it is often cheaper than even supermarket 97 elsewhere. Funny old world, isn't it!!!

Same here, although I use Sainsburys 97 iof Tesco 99 is unavaliable, like it isn't at the moment. Would rather use 97 than 95.

I just noticed that on the one bl**dy pump I used to refill yesterday the label on the super grade said 97 RON. All the others around say 99 RON. So I have emailed them to see if this is just an out of date label.

I mentioned in an earlier thread that none of my "local" (nearest is 20+ miles) Tesco stations sell 99 RON. Their premium grade is 97 RON.

I mentioned in an earlier thread that none of my "local" (nearest is 20+ miles) Tesco stations sell 99 RON. Their premium grade is 97 RON.

Interesting. But would a particular station have a single 97 pump amongst a load of 99's?