Fuels - Which one do you use?

[Minch]

OK Guys, quite an interesting topic which has been touched on in a few other threads now. Think its time to start a proper thread.

So which fuel octane do you use?

Which brand (BP, Esso, Shell etc)?

Have you noticed a difference between the octane/brands?

Did you reset the ECU and did this, in your opinion, help?

I've got three track days looming and if there are any tips to peak performance I'd be very interested.

Cheers
Nathan

[Kevin]

Well as a starting point we could name (and shame) the petrol that was in our cars for the dyno day. At least there will be some real world comparision.

Mine was BP 95 normal unleaded stuff. As the car doesn't get used much it was probably in the tank for months.

The biggest factor in performance at the track is in your driving, not some petrol.

[simonprelude]

Indeed, as Kevin say's.

Higher Ron fuel may well give you a few extra ponies that may help on the straights, but on a track the main driving is done in the corners, no petrol will help you here.

Anyway, I use Shell 95 Ron wherever possible, Optimax / V-Power or whatever it's called every now and again if there is less than 3p a litre between that and 95 Ron.

[amo]

same here only use shell v power so cant say anything about usin the others

thx amo

[AR]

Well I had to use Morrisons 95 the other day as I was close to E, but normally use Tescos 99.

Anyone uses any octane boosters?

Cheers,

AR

[Lankstarr]

I use Tesco 99 or 95, I don't notice any difference but sometimes take the 99 just in case if it's a Sunday night and I think some new stuff is in!

Maybe the 99 sits there for longer and degrades to 95 most of the time anyway!

Had ECU reset and 99 for RR day but think that any difference noticed were pyscological.

L*

[Papalazarou]

Well I had to use Morrisons 95 the other day as I was close to E, but normally use Tescos 99.

Anyone uses any octane boosters?

Cheers,

AR


I sell octane booster to the trade.
Some of our injection cleaning products also contain octane booster.
However, octane rating is not the whole story. It very much depends what kind of car you have.

There was a thread a while ago talking about calorific values of fuels but I guess it got lost when the site changed.

Anyway here's something I robbed from another site earlier which explains to a point, the values and used of different fuels............

Pump Petrol has a slightly lower calorific value (14,700 15,400 calories per LB of fuel) but it has a much higher anti auto ignition temperature & knock, or detonation temperature. In other words a diesel engine would not fire! It NEEDS a spark for ignition. That is until you increase the temperature or boost level, in the cylinder!!! And then we get detonation problems. Detonation is when the fuel spontaneously explodes rather than smoothly burning. It destroys engines very fast! So we need higher Octane fuels for really high compression use, or high boost levels with a turbo etc.

Race fuel, C14, C16 etc These are the same as pump fuel but much higher Octane. Used in a car that does not need this extra octane it is simply a waste of money. To see more power you need to take advantage of the new higher detonation limit! By increasing boost, or by increasing compression ratio.

Methanol is a "cold" or "cooling" fuel, that is basically alcohol. It is VERY high octane so really high compression ration can be used. Because it has only 7,000 approx calories per LB 2.2 to 2.4 times as much is needed at any one time! This means HUGE fuel jets are needed, and a corrosion proof fuel system, You cannot just run your engine on it! If used in a similar motor to a petrol one no extra power will be available. But it again allows higher compression ratios, or more boost! So in this case more power can be realised.

Nitromethane is not really a fuel, on its own but almost is! It is however an oxygen producer! As we already know, oxygen allows fuel to be burned! This stuff is a way of getting more oxygen into your engine! But its £50 per gallon price, and the fact that it makes all kinds of nasty acids that turn your oil to milky water in ten mins flat mean race use only! It is used mixed with methanol normally as its fuel. Although its almost a monopropellant, engines breath air, so "some" fuel has to be added. It is added to methanol base fuel, and can be used in 5 percent up to high 90's percentages! Obviously the more Nitromethane that is added to the fuel the more oxygen you have added. So you then need more fuel! So you go in ever decreasing circles as the percentage rises until you simply cannot feed it enough fuel! Strange stuff. Works though. Top Fuel dragsters make 5,000 bhp! Go from 0 to 300 mph in 4 seconds. From low tech pushrod V8 engines... A similar effect could be had by adding oxygen via a Nitrous Oxide Injection System.


Cheers,

James.

[Steveycaz]

I now only use Shell v-power and have not reset my ECU. For the 3 months I was using 95 RON I averaged 21.7 MPG, for the 4 months I've been using v-power I've averaged 22.1 MPG! I have consistently averaged 19p per mile despite the change to more expensive v-power. I want to believe that I am taking better care of my engine and maybe getting better performance by spending the extra few pence! How to tell though?

[gumball]

I now only use Shell v-power and have not reset my ECU. For the 3 months I was using 95 RON I averaged 21.7 MPG, for the 4 months I've been using v-power I've averaged 22.1 MPG! I have consistently averaged 19p per mile despite the change to more expensive v-power. I want to believe that I am taking better care of my engine and maybe getting better performance by spending the extra few pence! How to tell though?

same here.

[Senninha]

So which fuel octane do you use? Was Optimax, now V-power wherever possible. Was run on Tesco 99 by previous owner.

Which brand (BP, Esso, Shell etc)? err, Shell ;)

Have you noticed a difference between the octane/brands? I switched to V-power when I did the airbox. Overall impact was a smoother, quicker revving engine. More a combo than fuel alone.

Did you reset the ECU and did this, in your opinion, help? Yes I did, but I'll have to ask the ECU if its happier now.

I've got three track days looming and if there are any tips to peak performance I'd be very interested. Driver training regardless of your current skill level!

regards, Paul

[Minch]

Cheers chaps . . . as I thought, no real magic formula then. Just keep her happy with the decent juice.

I am still considering where to go for driver training but I think that is best left to a new thread . . . .

So here goes . . . .

[AR]

I sell octane booster to the trade.
Some of our injection cleaning products also contain octane booster.
However, octane rating is not the whole story. It very much depends what kind of car you have.

Cheers,

James.

James I was thinking more along the lines of a booster that say could turn 95 or degraded fuel back up to 99 or thereabouts, where the NSX is happier.

Any such thing?

Cheers,

AR

[markc]

I always use Shell V-Power (99 RON) in the NSX and even in my 540i Touring daily driver. It obviously helps that I have a Shell station close to where I work.

I started using Shell Optimax years ago in my Prodrive engined Imprezza and carried on with my 993 and now the NSX.
I can't be sure that it really does any good but I've never read anything bad about it and mainly positive things about power and engine cleaning.

Mark

[Papalazarou]

James I was thinking more along the lines of a booster that say could turn 95 or degraded fuel back up to 99 or thereabouts, where the NSX is happier.

Any such thing?

Cheers,

AR

There are a couple of products;

1. Octane booster; which boosts octane levels, but only up to a level. High concentrations do not mean guranteed higher levels; there is a satuation point.

2. Fuel stabilzer; for vehicles which are layed up for extended periods; this product stops fuel from degrading and leaving deposits in your fuel system. fuel degrades quickly after 60 days.

Cheers,

James.

[TheSebringOne]

I read article in Evo car mag 4 serious petrol heads,that Shell V-power & BP Ultimate r comparable,but Ultimate gives 28mpg more in full tank,but as cost more than V-power,extra mpg cancelled by higher cost.Maybe try BP 102 jus 4 trackday but costs gulp 2.5 times than BP ulimate !! Evo rolling road tested a 996 GT3,got 25BHP more & when remapped ECU, extra 48BHP or 12.5% ! Im a V-power man as crispest & fun or is that in my head !?! :D