Hi,
Has anyone tried higher octane fuel along the lines of Shell Optimax, BP Ultimate etc. in a 1.2?
Any improvements in driveability/mpg?

At the mo town driving with the odd 4-mile A-road drive to work is producing an average mpg of 39.8

I've used it and i find it makes the engine more willing, and it does give better mpg on a run. But i don't use it all the time, it just seems so much more expensive. Our Panda doesn't get used for serious short journey's like yours, so we average 47-54mpg, the higher figure more easily attainable in the summer. But i remember a 30 mile journey whilst using Optimax i nursed the trip computer to read 63mpg average,(i don't think i went over 50mph, and the car was empty) take off the 3mpg inaccuracy of my trip comp and that's 60mpg. So i believe it does help, but it's also expensive, which means i don't buy it very often.

Does it take long for the difference to show? When I'm running on empty I may fill up with optimax just to see for myself, an expensive experiment i know

I think you can tell as soon as you leave the forecourt, but maybe i'm imagining it.

i tried it last summer, back to back with the pajero (1.1L 16v) the paj was smoother, willing to rev and felt lot better, esp on the long run to skegg, the panda...didnt like it at all, and appeared to idle and run a bit rougher, back to 95, smooth as you like....

It works well on my 250 two stroke

Jai said:

i tried it last summer, back to back with the pajero (1.1L 16v) the paj was smoother, willing to rev and felt lot better, esp on the long run to skegg, the panda...didnt like it at all, and appeared to idle and run a bit rougher, back to 95, smooth as you like....

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Hmmm I wished id seen this before I put 30 litres of the stuff in my car! So used to the old fiesta and the 97% petrol! Ok so she's just started 'farting' on idle and smelling a bit rotten eggy! But When she's above 1000 rpm she's as responsive as ever. According to my range message ive got another 280 miles of this! OR maybe a quick trip down the A46 in 3rd gear! lol (only kidding!)

I remember watching an episode of Top Gear (not the greatest source I realise) a few years back where they looked into this.
Their conclusion was that it did help, a bit, but was only cost effective and worthwhile if you had a performance car to match.

I can't remember the 'normal' car they used but I do know the performance car used was an Impreza.

Most engines are designed to run on a lower octane than the regular stuff in the UK. Putting higher octane fuel in is mostly wasting your money.

I just googled fuel prices and was shown averages of £1.11 for regular, and £1.21 for super. That's a 9% higher price. I seem to remember that the fuel companies claim about a 3-5% improvement in fuel consumption. Isn't that therefore more expensive per mile?
Different octane rated fuels burn at different speeds. (It is not an explosion but a rapid burn) Changing this may not suit your car.

I find the more expensive fuel leads to a cleaner engine with fewer emissions. Having made the switch some years ago now, every MOT emissions test I’ve passed with flying colours and that’s on an engine with 130k. In addition the spark plugs come out much cleaner when running on premium fuel. It all depends how long you want to keep your car and how much you value the bits inside the engine that you don’t usually see.

TBH I haven't tried it in the Panda yet, but as I'm going on a run up to the passport office in Newport on Thursday - mostly motorway and about 300 miles round trip - I'm going to give it a go and see what happens.
I used to put Tesco Momentum (99 octane) in our Smart Roadster and it definitely improved performance but I never measured the consumption difference...
Could be an interesting experiment.

Compress petrol and air together enough and it will eventually self combust (auto ignite) without the need for a spark.

Very lower octane fuels tend to pre combust before the spark fires (pink or ping) and cause engine knock, the mix can combust before the spark and before the piston reaches TDC.

The higher the octane rating the higher this auto ignition point of the fuel.
So it can be used in very high compression engines and be squeezed into very small combustion chambers without it auto igniting.

A few years ago some high performance engine really needed it to stop the knock.

These days modern cars are fitted with knock sensors on the cylinders and they'll automatically adjust the spark timing to stop the knocking so there aren't too many vehicles on sale these days that actually require the higher octane fuel.

I'm certain the 1.1 and 1.2 FIREs aren't on the list!

I think people choose it these days and they "trust" the fuel and the additives they add to it and feel there's a benefit.

I've a high strung 2 stroke competition bike that'll rattle the filling out of my mouth on anything less that 99 and I once hired a bike in Indian, it was an Honda single cylinder 4 stroke with three plugs and coils, I asked the reason why and the hire shop said their fuel is like water with such a low octane rating it needed three separate sparks just to stop it knocking it's self apart!

Been using it in my 100hp for about six months now and it revs cleaner, feels smoother and gives a few extra mpg's too according to the trip computer.
I've seen all the tv programmes that say it doesn't make any difference but I disagree and i'm using it more than just a few miles on tv.

I've put 6 tankfuls through our 2010 1.2 Eco so far, half normal 95 RON and half Shell V-Power. Haven't seen any significant improvement with the high octane stuff.

(All mid-to-high 40's mpg. Actually, the numbers look a little better with the standard petrol but I'm pretty sure that's just a coincidence rather than a real effect. It'll probably average out over more fillups.)

Some cars do seem to gain a bit of economy with high octane fuel but my objective experience is that many don't. I suspect the biggest improvement in mpg comes from having the driver constantly thinking about what mpg they're getting.

Martin Y said:

I've put 6 tankfuls through our 2010 1.2 Eco so far, half normal 95 RON and half Shell V-Power. Haven't seen any significant improvement with the high octane stuff.

(All mid-to-high 40's mpg. Actually, the numbers look a little better with the standard petrol but I'm pretty sure that's just a coincidence rather than a real effect. It'll probably average out over more fillups.)

Some cars do seem to gain a bit of economy with high octane fuel but my objective experience is that many don't. I suspect the biggest improvement in mpg comes from having the driver constantly thinking about what mpg they're getting.

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Never even give it a second thought..

My BMW 1200 bike runs better on posh petrol and gives enough better mileage to pay for the higher cost fuel.

The 2.0T Renault Espace was the same to the extent it felt flat as a fart on vanilla 95-RON.

the best thing about most super petrols is they have less ethonol in them and some makes have none at all this is a good thing for most fuel systems as ethonol affects rubber components in the fuel system and it evaporates faster as well

rick500 said:

the best thing about most super petrols is they have less ethonol in them and some makes have none at all this is a good thing for most fuel systems as ethonol affects rubber components in the fuel system and it evaporates faster as well

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Ethanol in fuel also makes the fuel collect water, which then corrodes metal components inside the engine. Ethanol has a lower specific energy content than petrol, so adding ethanol means the car will do less miles per gallon.

I'd gladly buy a premium fuel if it were guaranteed not to contain ethanol.

I think that higher quality or 'premium' fuels exist only for cars with engines that NEED it and will not work properly without it..

I dont think there's any guarantee of how engines without the need benefit from it, but personally speaking I don't think my Panda performs badly or gets bad MPG anyway so I don't feel the need for it.

I'm not a scientist, so what I say could also be a load of bs, but just my two cents.

In a modern car with knock sensors, lambda sensors, electronic injection and fly by wire throttles, the car will run just as well on 95RON or 97/98RON 'super' fuels - the computers will sort all that out. The key difference with the 'super' unleaded (and also 'super' diesels fuels) is they have much more of the cleaning 'detergents' in them, so injectors etc will (or can be) cleaned out and be able to operate better (in an older car). Generally it is this that results in 'perceived' better running and improvements in MPG.

The promotional websites from the fuel companies more or less 'admit' this is the primary difference.: for example:
http://www.shell.co.uk/motorist/she...o-plus/shell-v-power-nitro-plus-unleaded.html - which says "Shell V-Power Nitro+ Unleaded is formulated with powerful cleaning agents designed to protect key fuel system components from gunk " - no mention of higher octane or more power...
While BP says (here: http://www.bp.com/en_gb/on-the-road...ultimate-unleaded-with-active-technology.html) "Our new range of dirt-busting BP Ultimate fuels is designed to help your engine run efficiently,"

In older cars, with carburettors, contact breaker ignition etc, then yes, they may well work better, as there is no computer compensation going on there.