RS246.com Forum :: The World's #1 Audi R, S and RS Enthusiast Community

I'll be getting my S4 on Friday [img]images/graemlins/biggrin3.gif[/img]

What is the correct petrol to use - normal unleaded, super, Optimax???

cheers,
Andy

I think you'll find that the majority will recommend Optimax - it is a higher octane than standard unleaded and contains chemicals which have been proven to keep you engine cleaner and make it run smoother. It is also cheaper than superunleaded. [img]images/graemlins/jump_clap.gif[/img]

However, I have asked the question about the use of Millers Octane Booster (1 bottle of Millers OB per tankful raises the octane of the fuel by 2 points)- but Optimax is, as far as I know, standard unleaded with octane-boosting chemicals. Therefore I wondered if there was any benefit to adding Millers to Optimax and expecting to get 100 octane performance. [img]images/graemlins/bigwave.gif[/img] - "hello"

I have therefore recently been using super unleaded plus Millers, expecting to get 99 RON to see if I could feel any difference,

and guess what..........

.......I couldn't [img]images/graemlins/jump.gif[/img] [img]images/graemlins/062802beat_prv.gif[/img]

Your car has been given its performance figures using 98RON fuel. So to get the 265bhp you need to run 98RON fuel, if you use 95 std unleaded you will get maybe up to 4% power loss

Optimax is the closest we have to 98RON in the UK so it makes sense to use it

Obviosuly if you use millers octane booster you should get to say 100RON which may give 2.5% power increase

I'll be getting my S4 on Friday [img]images/graemlins/biggrin3.gif[/img]

...bet you can't wait - no wonder you're grinning [img]images/graemlins/greyrs4.gif[/img]

but Optimax is, as far as I know, standard unleaded with octane-boosting chemicals.

I am lead to believe that it is produced to 98RON without using octane boosting chemicals.
So Optimax and Millers for me everytime [img]images/graemlins/thumb.gif[/img]
Enjoy the new car, I know you will [img]images/graemlins/sloppy.gif[/img]

Don't know where I heard that from - I think it was some months ago on one of the other Audi sistes - but is this is the case Paul it's really good news [img]images/graemlins/1syellow1.gif[/img]. Thanks for the info. [img]images/graemlins/thumbs.gif[/img]

Congratulations on the new car!

You won't be disappointed.

I follow the herd and normally use Optimax. Have to say that I had to fill up recently (running on fumes) somewhere where I could only get normal unleaded and didn't notice any difference.

David

Optimax is (allegedly) refined to an octane rating of 98. The only additives it contains are the cleaning agents which do work.

However. Optimax has been independently tested to be unstable IE yes, it IS 98 at the refining stage, but very quickly loses its potency under most storage conditions.

SUL though of a slightly lower octane rating (97) is more stable.

The Optimax issue was resolved on one of the Scooby sites. Shell responded to an email and said that Optimax did not use octane boosters, and they did not see any issues with using an octane booster with it - although they had not tried it.

Optimax is genuine stuff [img]images/graemlins/062802drink_prv.gif[/img]

HeHe. Is this graemlin [img]images/graemlins/062802drink_prv.gif[/img] meant to be drinking Millers? [img]images/graemlins/grin.gif[/img]

My S3 has been drinking optimax from day one! [img]images/graemlins/smile.gif[/img] [img]images/graemlins/s3addict.gif[/img]

However, I have asked the question about the use of Millers Octane Booster (1 bottle of Millers OB per tankful raises the octane of the fuel by 2 points)- but Optimax is, as far as I know, standard unleaded with octane-boosting chemicals.

Millers may raise the octane by 2 points dont forget this is 0.2 . ie from 98.0 to 98.2

If you want to experiment with some REAL octane booster try here http://www.vtr.org/maintain/gasoline-octane.html

I know a few friends that have tried Formula 1, in 1.8T engines and have noticed a good difference. However what the long term effects are is debatable.

To raise an octane rating by 2 real points ie from 98 to 100, you would need over 1 gallon of Toluene ( contained in cellulose thinners, available from all good motor factors) not a 500ml bottle of octane booster.

Thanks for all the replies guys [img]images/graemlins/clap.gif[/img]

I guess I'll do the same as I did with my Impreza - fill up with Optimax whenever I'm near a Shell station, and use super otherwise, only resorting to regular unleaded as a last resort. Unfortunately, the nearest Shell garage is about 20 miles away from my house, so I often find I have to use super.

Cheers,
Andy

Unfortunately, the nearest Shell garage is about 20 miles away from my house.....

And the problem is....? I love driving to the petrol station. Nice little cruise to the garage [img]images/graemlins/thumbs.gif[/img]

Millers may raise the octane by 2 points dont forget this is 0.2 . ie from 98.0 to 98.2

To raise an octane rating by 2 real points ie from 98 to 100, you would need over 1 gallon of Toluene ( contained in cellulose thinners, available from all good motor factors) not a 500ml bottle of octane booster.

Now that's something I haven't heard before. So basically you can just tip a gallon of toluene into your tank before filling up for a track day and all's well? [img]images/graemlins/confused.gif[/img]

Anyone else have any experience of doing this?