Always used normal unleaded in the Cooper.
In my previous car, a VW 1.6 FSI, the manufacturer recommended super unleaded but even with that I noticed no difference in performance or economy.
I would expect a difference in an S may be more noticeable.
more often than not
people think Ultimate and only think of the Octane.
However there is a lot more to Ultimate and Vpower.
The loss in performance from using ordinary fuels can be a gradual process, and correspondingly the performance benefits of using Ultimate can increase with time. The benefits of Ultimate can be seen in many different areas of vehicle performance, including engine cleanliness, power, acceleration, fuel economy, and exhaust emissions using industry standard tests.
In a typical test, a vehicle starts the test with a clean engine, is operated for several thousand miles on ordinary fuel and its performance is then measured. This demonstrates how performance declines as deposits build up in the engine. Then the vehicle is switched to Ultimate and the performance is measured again to show the immediate benefits of using Ultimate then continue to run the vehicle - in many cases for another 10,000 miles - to see how the benefits of using Ultimate can grow with time.
Now
Not to be confused with the title of this thread asking is we use unleaded or super unleaded as "super Unleaded" is not the same as Ultimate or Vpower.
The typical grades of Petrol are
Unleaded = standard grade fuel
Super Unleaded = standard grade fuel with octane booster
Ultimate =standard grade + additives + octane booster
Ultimate Diesel. = standard grade + additives + cetane booster.
Last edited by Scottie; 26th November 2008 at 09:36 PM.
Cooper Coupe...
How do I follow Scottiedoops post!!!
My personal belief is that these "super" petrols will only give you any noticable performance increase in a forced induction engine (turbo or supercharged)
As knock becomes a bigger problem as boost pressures increase, particularly above the 2 bar absolute mark where things start to melt very quickly if there is any knock for any length of time (a naturally aspirated engine can only ever reach a maximum of around 1 bar absolute "boost").
The Octane rating is a measure of the fuels resistance to knock, the higher the number, the higher the resistance, the less knock the more advanced the timing can be and the slower/longer the energy release from the fuel/air burn can be, which means more/longer "push" on the piston, which means more smiles!
Since knock is less of an issue and less damaging unless REALY bad (still a possibility though!) on a naturally aspirated engine, the increased knock resistance is less of a perfomance gain.
Regardless what petrol engine type you have, if it is a modern engine, you wont notice a differance when you first put in the "high octane" stuff. It will take a good 100 miles of "ordinary" driving for the ECU to re-adjust its ignition timing maps to learn the new knock values of the new fuel, and even then it will be a gradual change. The more accurate way to test would be to monitor the performance LOSS after driving the car on "high octane" fumes to the fuel station, then fill up with "cheap skate" petrol... the ECU will re-adjust alot quicker this way round, it will "learn" within a few seconds on full load.
As for me, I think my Passat TDi would not thank me very much for a tank of petrol... no matter how "super" it is!!
I usually use the cheap stuff, but did once buy a tankfull of the VPower diesel by mistake, cant say I noticed any differance at all!!
Last edited by C.Noble; 26th November 2008 at 10:25 PM.
I thought all decent fuels had detergent type additives in them these days?Originally Posted by ScottieDoop
Is that what you mean by additives? If not what are they?
advanced/additional additives that regular unleaded will not have.
regular unleaded as you will know is made up of sulfur ~ hydrocarbons aromatics@ 25% aromatics hence the strong sniff and alot more that I don't know.
LRP was brought out to replace Leaded that had an additive added to help seat the valves this product was then replaced Super unleaded which is unleaded but at a higher octane rating gained by adding a booster.
Cooper Coupe...
There was an article in the press or perhaps it was on TV that pooh poohed the notion that super fuels had any benefit in terms of performance. I suppose if they only did a very short test then their figures would have been accurate. I've been using v power or equivalent (I hope) since August. Chose to do this when the mileage started to really climb in an attempt to keep specy in as tip top condition as I can. I dont know if it has made any difference other than in my head. My head says yes but unable to ellaborate on why it says "Yes"
I've used v power periodically since he was born but when the price started to rocket and because of the mileage I was doing had fallen into the way of using ordinary petrol as I think many other people would have done. Nice to see the cost coming down.
Dear Lord, If you wont make me skinny, please make my friends fat-very Fat.
no option for chip fat
Diesel. Plain and Simple. I used to use Super unleaded in bikes but it made no difference. Incidentally 5th Gear tried this on a show last series and it actually reduced BHP on rolling road?
Unleaded here but I'm only going with Shell.......... Sad but it makes me feel better, used to put Super Market stuff in my Honda.......
Mini as it was. As it is. As it always will be. Everyone is entitled to their opinion, it's up to you to decide if it counts!
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