Why do people buy high octane petrol?

[TheVoice]

I ran my Golf R purely on Tesco Ultimate (98)
The only issue I found was that I had a few close calls of running out of fuel when I wasn't near a station with higher rating fuel. I was also late for work a few times due to travelling further in the morning to the Tesco garage.

That's not an issue with the fuel though.

 

[Meridian]

Out of the factory my car is marked at "98-RON or better". But it's since been remapped for 99-RON, so I'm stuck with V-Power or Tesco Momentum. The guy who mapped it (Paul Blamire) reckoned Tesco was actually slightly better. But every time you start the engine, the ECU advances the ignition until it hears knock, then pulls back slightly. Since every one degree of ignition addance is about 10bhp for me, I'm happy to stay with the good stuff.

 

[FurryLemon]

I put 98 in my ride on mower

I feel dirty buying 95 and derv for the 2 strokes and tractor. Peasant fuel.

 

[Akagi]

By Tesco Ultimate (98) I assume you mean Tesco Momentum (99)?

 

[MooMoo444]

My car has 98 on the cap but sometimes when convenient I'll just use 95. I don't drive spiritedly enough to notice.

 

[ubersonic]

I used to get people on JDM forums flaming me for using 97RON in my import spec Supra all the time because "everyone knows Japan uses 100RON!!!", my Supra was made a decade before Japanese garages first started selling 100RON, back when 97RON was the best you could get there

 

[Dogbreath]

Not the case. Some cars will even throw un-burnt higher octane fuel out of the back.

And which cars are these?

 

[Akagi]

And which cars are these?

 

[Meridian]

And which cars are these?

Many, if not all, turbo-charged ones. Actually they throw out unburnt fuel no matter what the octane rating, but I believe it gets worse as the octane rating rises. It's how they work - they run rich at all times. And it's why some people go decat and get a flamer kit.

 

[Frozennova]

Many, if not all, turbo-charged ones. Actually they throw out unburnt fuel no matter what the octane rating, but I believe it gets worse as the octane rating rises. It's how they work - they run rich at all times. And it's why some people go decat and get a flamer kit.

If anything it's the opposite, turbo engines particularly on factory tunes run very rich to give a margin of safety due to low octane fuels and high temperatures


I run the MX5 around 11.8:1 Petrol AFR, if I ran it on 95RON instead of the 102RON Meth/Vpower mix I'd run it richer and target around 11:3-11-5:1

There's generally no need to go fire puking black smoke throwing rich like some tuners seem to though

 

[robj20]

If your car is flaming its just not mapped very well. The odd pop or bang fair enough but not full on flames.

 

[timmeh]

What’s the deal with non-ethanol fuel too? People seem to go crazy for it. There’s a petrol station near me that sells it.

 

[Frozennova]

What’s the deal with non-ethanol fuel too? People seem to go crazy for it. There’s a petrol station near me that sells it.

Ethanol is cheaper way of increasing Octane rating. The downside is slightly reduced fuel consumption compared to a non ethanol fuel and on older vehicle may cause fuel system problems because fuel lines/carbs/injectors are not ethanol safe

 

[Molesy79]

I run V- Power on my Golf GTi and can feel the difference when other fuels are used especially inc BP Ultimate and Esso Super, the only one that feels nearly as good is Tesco Momentum but where I live/work Tesco's are miles off so the price difference disappears. Luckily Shell are the cheapest for super round my way.

 

[flinco]

I've recently started filling my 330i only with Momentum 99. It does feel like it has more urge on the stuff. Not complaining at 5p more than 95 or equivalent price to BP 95. There are a few downsides; the slightly less convenient location compared to Morrisons or BP and the annoyance caused by having to fill it with 95 when I won't pay the prices BP charge for their 97 and have no Shell/Tesco close by at the time.

 

[Django x2]

I buy it because the manufacturer of my vehicle tells me it is the fuel they have designed the car to run on, and the fuel I must use to acheive the quoted performance and economy figures.

Pretty simple, no?




Of course you are wrong. Why are you stating flawed opinion as if it were fact?

If they told you to run your car on Shell V-Power Diesel. Would you?

I'm playing devils advocate btw, as we all know there's no benefit to performance from Vpower Diesel or Momentum style fuels, petrol is obviously different.

 

[Frozennova]

If they told you to run your car on Shell V-Power Diesel. Would you?

I'm playing devils advocate btw, as we all know there's no benefit to performance from Vpower Diesel or Momentum style fuels, petrol is obviously different.

I can't seem to find any hard evidence but it does appear from a thread or two on Pistonheads that premium diesels do carry a higher cetane rating

 

[[TW]Fox]

If they told you to run your car on Shell V-Power Diesel. Would you?

Not the same thing, as that would be a specific brand recommendation rather than a fuel grade.

 

[Nasher]

Some DO recommend a specific brand lol

My Fiesta ST had a BP sticker on the inside of the fuel cap. But I was a rebel and didn't use BP.

 

[SupraWez]

On my motors that are mapped for VPower I tend to stick with VPower, although if stuck I can switch to a less aggressive map. If you have the ability to switch maps then a 95ron map can be very handy

If your car is flaming its just not mapped very well. The odd pop or bang fair enough but not full on flames.

Not always, it could be because the owner has requested it, in fact its quite a common request, since its an area of the map that doesnt affect general driving or full power its entirely up to the owner