Which fuel?

[Delk]

Octane is a measurement of how well a fuel resists knocking and detonation. High performance engines need high octane fuel, not much of a performance gain otherwise.

https://en.wikipedia.org/wiki/Octane_rating#Effects

 

[andyglym]

View: https://youtu.be/gQghB4asSnI


The ///M will get best gains, then the 3.0 followed by the 2.8. After that probably only a very minor to no difference .

 

[t-tony]

I have to say that my cars "seems" to run better on the higher octane but no better MPG for sure.

Tony.

 

[ktnez99]

Interesting post and comments. Does the petrol help maintain the engine? For example, longevity of the engine?

 

[gookah]

I have tried all of them, shell, bp, momentum etc, and notice not the slightest bit of difference to performance, economy, or emissions
I just notice a bigger spend.

There again, my dad always said the prudential were best for insurance, because they cost more !!!

you get what you pay for....... and get stung on other occasions.

 

[EnthuZiaZT]

Oddly I started using V-power in mine when I bought it, since changed over to ordinary 95 Ron Shell and it seems to run better. I may go back to my old practice of filling up 3 times on 95 Ron and once on V-Power.

Mike

 

[andyglym]

Mine just runs much sweeter on better fuel. Much sweeter

 

[t-tony]

Mine just runs much sweeter on better fuel. Much sweeter

That's the feeling I have Andy, but I can't put my finger on exactly why.

Tony.

 

[andyglym]

That's the feeling I have Andy, but I can't put my finger on exactly why.

Tony.

It's just the whole drive Tony, just more crisp compared to standard fuel, moreso when you're clogging it, much better pick-up without doubt.

 

[2DunnsZ3]

over here there is 87 89 93. I always run the 93 and once a yr throught a small can of injector /fuel treatment to a tank full. only once the wife put cheaper fuel in and it knocked like hell if you didn't down shift and made it pull. never have that with better fuel. Its my toy so it gets the best of everything

 

[FRANKIE]

View: https://youtu.be/gQghB4asSnI


The ///M will get best gains, then the 3.0 followed by the 2.8. After that probably only a very minor to no difference .

Good video............answers the question well....................Frankie

 

[Ianmc]

Simples really, just buy the best you can afford.

 

[MalcQV]

I had heard about a test using a Golf GTi so perhaps it was that.
The handbook for two of my cars suggests 95 Octane RON (noted above in the US they use AK) and with my new Merc I have never bothered to open the manual, however that 95 recommendation might well be because in the video they said all cars for the UK must be able to run on 95 Octane.
Had this discussion on many forums and it's always as diverse as this. I'll probably continue to use high octane on the one car wherever possible.
However it's not like I'm tracking it (not so far) and whilst I love a good A or B road, racing another car never comes into it so I'm not sure Ultimately (pun intended) it matters.

 

[Redline]

Very few engines nowadays need high octane. Just high performance cars. Manufacturers now use the same engine and derivatives across whole ranges. They’re designed to work to the lowest common denominator - fuel quality. Our fuel is much better than that in many other countries. The companies sell higher octane here simply because people will buy it whether needed or more commonly, not.
Yes - the detergents added (to justify the higher prices) will be helpful but not critical.
In conjunction with high standards of fuel the ecu is adaptable to the fuel it’s fed with. Combustion is managed dynamically to maximise the consumption and minimise pollutants. This helps keep the engine from needing a de-coke like we used to.
Pays your money etc.

 

[mmm-five]

I use V-Power where I can, then fall back to Tesco Momentum 99, and I used to also use Costco Super (until they reduced the rating).

In Germany I use Aral Ultimate 102 RON, as it’s cheaper than UK V-Power.

 

[Pingu]

It's not the octane of the fuel that provides the power. The power in each drop of petrol is roughly the same, regardless of the octane.

The octane rating is only important because you don't want the fuel to pre-ignite. A fuel with a low octane is more likely to pre-ignite in a high compression engine.

A high compression ratio engine needs high octane fuel or it will be damaged. All others can run on high or low octane.

If your compression ratio is less than 10.5:1, just use which ever pump you like.

BMW Z3 Specifications

It looks like the M, the 2.0 and the 2.2 would benefit from high octane, the rest just need Asda's finest.

 

[t-tony]

Pinking or pre-ignition is also sometimes reffered to as "dieseling" which is the same effect you get in a diesel engine when the fuel isn't atomized enough before combustion occurs that's when you get diesel knock. It's all about efficient combustion not power gain.

Tony.

 

[Pingu]

Pinking or pre-ignition is also sometimes reffered to as "dieseling" which is the same effect you get in a diesel engine when the fuel isn't atomized enough before combustion occurs that's when you get diesel knock. It's all about efficient combustion not power gain.

Tony.

It used to happen a lot when cars sooted up and the carbon deposits were still glowing and the fuel came in on the next cycle. Most cars don't soot up now, so that problem has virtually gone.

Same with wrongly set ignition - no longer a problem.

I agree with you, efficient combustion leads to power gain. High octane fuel leads to more efficient combustion. It's not required in a low compression engine, unless that engine is knackered and you don't want to fix it. Thinking about it, running it in a low compression engine could actually be a bad thing, because you are masking the types of problems I mentioned in the first two paragraphs.