Premium fuel.

[Dirk]

I did a fair bit of dyno testing on motorcycle engines in the '90s some of which revolved around fuel grades and brands.
Basic conclusions?
1. Higher octane fuel, in a stock motor, actually reduces maximum power. This is because it burns slower.
2. Regardless of brand of fuel, always buy it from a pump that has a high turnover ie. 'fresh fuel'

So, simply put, if you want max power - run the lowest octane fuel your engine will stand, without detonation occurring, and buy it from a busy petrol pump.

 

[rugby bloke]

I'm taking delivery of an old Alfa Spider in a few weeks ('87). It has twin Webers,....

Now there is a collection of words to quicker the heart .... Brings a smile to the face just thinking about it. I applaud you on your taste Sir !

 

[Smurfy]

Great picture!

 

[Fab Foodie]

I happen to know that @vernon runs on premium absinthe. He says it's worth paying the extra.

Yeah, but the emissions ....

 

[Milkfloat]

My Golf GTi (remapped) certainly gave me better fuel economy on 98/99 RON, I would like to think that performance was improved as well, but that could be purely placebo. I only used 95 RON when there was no other option.

 

[Nigel-YZ1]

I only use cheap supermarket petrol which I'm reliably informed by the office waffler contains added water to make it cheaper and will make my engine rust from the inside.
Formula Shell made my Dad's Hillman Hunter Super a bit perkier when it came out 30+ years ago, but anything would benefit a car that made the Millennium Falcon look shiny.

 

[PhilDawson8270]

the bike retards the ignition to avoid knock, and lose a 3 or 4 brake into the bargain.

Very few, if any road bikes have a knock sensor to detect when it starts to signal it to retard the ignition.

 

[PhilDawson8270]

My mate's Honda CBR 600 wouldn't run properly on anything other than BP. When he bought it the previous owner told him not to chance it with supermarket fuel, and he found out the hard way that this was true when he had to drain the tank and refill with BP. However, very few car engines would be as highly tuned as a Honda CBR 600.

My CBR600F2 ran fine on all fuels, my CBR600RR 2009 also ran fine on all fuels, my 2002 R6 ran fine on all fuels, the 2010 R1 also ran fine on all fuels. Motorcycles aren't delicate little flowers.

 

[Markymark]

Motorcycles aren't delicate little flowers.

Just their riders

 

[Smurfy]

My CBR600F2 ran fine on all fuels, my CBR600RR 2009 also ran fine on all fuels, my 2002 R6 ran fine on all fuels, the 2010 R1 also ran fine on all fuels. Motorcycles aren't delicate little flowers.

Just saying what my mate told me. Maybe his bike had been remapped. Bikers changing things to increase performance isn't exactly unheard of. Each year when he took it for the MOT the tester asked if he still had the original (road legal) exhaust at home.

 

[PhilDawson8270]

Just saying what my mate told me. Maybe his bike had been remapped. Bikers changing things to increase performance isn't exactly unheard of. Each year when he took it for the MOT the tester asked if he still had the original (road legal) exhaust at home.

Getting additional power out of already very highly strung supersports bikes isn't a trivial task. It is also possible he put diesel in by mistake, had to get it drained, so uses the "supermarket fuel" story to save face.

The only difference between supermarket fuels and branded fuels are any additives, as the base fuel is the same, and conforms to the same standards, you can actually check that on the pump too.

So, why would the Japanese design an engine that doesn't run on a countries most common fuels? Especially considering that Japanese standard fuel is around 90 RON iirc.

I have seen some engines specify 98+ but certainly not anything as bland as a CBR.

 

[Drago]

The Japanese are an odd lot. It possible to buy 101 RON quite widely over there because of their fondness for small bore screamers.

 

[Tin Pot]

Does anyone pay the extra few pence for premium fuel and is it worth it? Does the engine run smoother and do you get extra mpg? I have a diesel engine and wonder if I should buy primium diesel?

Yeah. Apparently you get the extra mpg according to the geeks who have spreadsheets of every journey they make.

 

[Smurfy]

Getting additional power out of already very highly strung supersports bikes isn't a trivial task. It is also possible he put diesel in by mistake, had to get it drained, so uses the "supermarket fuel" story to save face.

The only difference between supermarket fuels and branded fuels are any additives, as the base fuel is the same, and conforms to the same standards, you can actually check that on the pump too.

So, why would the Japanese design an engine that doesn't run on a countries most common fuels? Especially considering that Japanese standard fuel is around 90 RON iirc.

I have seen some engines specify 98+ but certainly not anything as bland as a CBR.

I think his bike was an F2 model.
https://en.wikipedia.org/wiki/Honda_CBR600F
Presumably it was originally intended to run on Four Star, which all but disappeared from forecourts in 2000.

 

[Dirk]

In a bog standard engine, as per manufactures specification, there is nothing to be gained power wise from using any fuel of a higher octane rating than they specify.
Using higher octane fuel will only be advantageous if the engine has been modified eg. higher compression ratio, ECU remapping etc.
Pretty much all 'improvements' that people say they have gained, just by filling up with a higher octane fuel in a standard engine, are purely subjective.
Personally, I always fill up at the cheapest, busiest, place - generally Tescos around here.