What do you use unleaded or super unleaded?

[..S-J..]

Out of curiosity I was wondering what people filled there cars with.

I have filled mine with Super unleaded since I got it so I cant say if there is a difference between them.

Has anyone noticed a difference in MPG or any change it the way your car drives? Basically your thoughts and experience :smilewinkgrin:

[euan]

I used to mix it up on my S, mainly used unleaded but did fill up with super every now and again - this was when it was cheap though! In terms of difference - it felt pretty marginal but it did feel smoother.

I notice more of a difference now in the 3 series - I get more MPG (I have a spreadsheet - it's very sad) than unleaded, but it works about the same as unleaded in overall cost per mile.

[Craig]

I use normal unleaded in my current coop.

When I had my 2 S's, I dabbled with Super Unleaded in both and really could not tell any difference.... I think if the car is modified, then you may feel the difference, but as Euan says, even if you get better mpg, then the cost per mile works out about the same. I certainly couldn't say that the super stuff gave me any extra power.. ;)

[Gismo]

Always use the super stuff, can't compare

[AndyP & Lenore]

Good post SJ. I've added a poll. Made it a multiple choice poll too, for those who own a Diesel can as well as a petrol car.

A.

[Craig]

Good post SJ. I've added a poll. Made it a multiple choice poll too, for those who own a Diesel can as well as a petrol car.

A.

would it not be prudent to spell diesel right in the poll :rolleyes: and maybe to put Super Diesel as an option (ie VPower Diesel). ;)

[AndyP & Lenore]

would it not be prudent to spell diesel right in the poll :rolleyes: and maybe to put Super Diesel as an option (ie VPower Diesel). ;)

Some folk.:frown:

Diesel is spelt right. It's you that cannae read right.:moonie:

A.:D

[S7JGW]

I put in Super if it available as seems to make a slight difference.
I generaly notice more of a difference when i go back to normal Unleaded after using Super.

[Hamish]

I use Super in my road car, but only cos the manufacturer says this is what I should use. I have had to put the 'odd' tank of normal in but if I have to I throw in some octane booster. I think the main improvement is it will burn cleaner with less impurities so keep the working parts of the engine cleaner, (am I right? I'm no expert... so feel free to correct me any1:thumbs up:). Dont really notice much in the way of performance to be fair.

[..S-J..]

Good post SJ. I've added a poll. Made it a multiple choice poll too, for those who own a Diesel can as well as a petrol car.

A.

Thanks, its a question that has been bugging me making me wonder if I am wasting my money on the super unleaded.

There is a site called petrolprices.com which tells you the cheapest places to fill up near your house.

[KenL]

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.

[Scottie]

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.

[C.Noble]

:eek: How do I follow Scottiedoops post!!! :eek:

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 :yes nod:!

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 :argh:, cant say I noticed any differance at all!!

[KenL]

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.

I thought all decent fuels had detergent type additives in them these days?

Is that what you mean by additives? If not what are they?

[Scottie]

I thought all decent fuels had detergent type additives in them these days?

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.

[Sheilz]

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" :thumbs up:

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.

[eddie 44]

no option for chip fat :p

[moraymini]

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?

[Stewart]

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.......