[RockIt]

Thought people might be interested in this interesting piece of research by What Car? Online.

http://www.whatcar.com/news-special-...aspx?NA=228253

[NFS]

EVO and Top Gear have both done features on this in the past.

From memory Top Gear (TV show) did a rolling road test for various cars.

They both concluded that for most cars there was little benefit to superunleaded. However, for performance cars (top gear tested an EVO I think) they found that there were measurable increases in horsepower.

So ... superfuels are a waste of time, unless you have a performance car.

[dxb335d]

will smaller engined cars (petrol) i can see why there is no gain

now with a 911 turbo, re-mapped to run higher boost will make more bhp, and can again be re-mapped to run on the higher octane fuel giving approx 15-20bhp, but the car would have to be run on that fuel with the new map!

Carlos

[NFS]

Originally Posted by dxb335d

will smaller engined cars (petrol) i can see why there is no gain

now with a 911 turbo, re-mapped to run higher boost will make more bhp, and can again be re-mapped to run on the higher octane fuel giving approx 15-20bhp, but the car would have to be run on that fuel with the new map!

Carlos

There will be more HP for a high performing car even without a remap.

[dxb335d]

Originally Posted by needforspeed

There will be more HP for a high performing car even without a remap.

yeah but marginal, where as re-mapped for that specific fuel, good gains can be made!

[NFS]

Originally Posted by dxb335d

yeah but marginal, where as re-mapped for that specific fuel, good gains can be made!

From memory the top gear test found that higher performance cars (they tested either an EVO or Imprezza - can't recall which) had significant gains - 20hp plus I think - when tested on a rolling road.

[dxb335d]

Originally Posted by needforspeed

From memory the top gear test found that higher performance cars (they tested either an EVO or Imprezza - can't recall which) had significant gains - 20hp plus I think - when tested on a rolling road.

pretty impressive.. i dotn notice anything with bp ulimate

[RockIt]

For daily driving, sat in traffic 5 miles to work, I stick to 95. When venturing out at the weekends I tend to bung in super unleaded. Can't feel a massive difference I have to say.

[beemerbird]

As fuel appears to be 'topical' at the moment, wondered what your thoughts were on whether I should run the Cayman permanently on super unleaded or just occasionally?

The manual clearly states that it will happily run on 95 octane unleaded as the OBC adjusts the timing accordingly. However, as per BMW manuals, they CLAIM best performance and MPG will be gained by using 98 octane fuel.

Any thoughts pse. guys. Thanks.

[Gibbo]

Helen, to get the ball rolling again.

Always used Super in my Boxster as I thought it was worth it and Porsche said to use it.
Used super for about a month in z4 could tell no diff. mpg or performance.
Always use std. in me diesel.
Never use supermarket fuel as I have heard less aditives but might be old wives tail
Try to use a busy garage as fuel apparently is best when fresh.

If I owned a cayman S I think I may go with regular and give it a super fill up 1 in 4 maybe. I would deffo run a couple of tanks of super through it to see if you feel any diff. or better mpg.

Or the other way of looking at it is.

Super 3p more a litre for you 11,000 miles is £75 quid a year difference. Surely you can give up a pair of Jimmy Choo's for a drop of the hard stuff.

[jasongtr]

Originally Posted by Gibbo

Helen, to get the ball rolling again.

Always used Super in my Boxster as I thought it was worth it and Porsche said to use it.
Used super for about a month in z4 could tell no diff. mpg or performance.
Always use std. in me diesel.
Never use supermarket fuel as I have heard less aditives but might be old wives tail
Try to use a busy garage as fuel apparently is best when fresh.

If I owned a cayman S I think I may go with regular and give it a super fill up 1 in 4 maybe. I would deffo run a couple of tanks of super through it to see if you feel any diff. or better mpg.

Or the other way of looking at it is.



Super 3p more a litre for you 11,000 miles is £75 quid a year difference. Surely you can give up a pair of Jimmy Choo's for a drop of the hard stuff.

never noticed a real difference in using super,
supermarket fuel surely comes from the same refinery,
a busy garage - please petrol isnt carrots dont think it goes off, i had a car sat on my driveway for 9 months - charged the battery and off she went like it did when i parked it up

[willhollin]

Originally Posted by jasongtr

please petrol isnt carrots dont think it goes off, i had a car sat on my driveway for 9 months - charged the battery and off she went like it did when i parked it up

You would be surprised what happens to fuel after a time, petrol goes stale and diesel begins to develop bacteria!

Im my line of work I deal with fuel storage and I got called to a garden centre. They had stockpiled 15,000 litres of derv for their lorries to run on during the fuel strikes a few years back. Trouble was the shortages never occured as they imagined and the fuel sat their for much longer than they had planned. They called me out when problems with their fleet pointed to the fuel. It was full of this bacterial growth and had started to emulsify! An expensive mistake as it was all scrapped.

[hmi1750]

I used to use super or v-power etc in the Mazda6 MPS I had and noticed a marked increase in performance and mpg, the car was much smoother.

In the beemer I run v-power from time to time, but normally its shell or just sainsbury's as its the cheapest.

[jasongtr]

Originally Posted by willhollin

You would be surprised what happens to fuel after a time, petrol goes stale and diesel begins to develop bacteria!

Im my line of work I deal with fuel storage and I got called to a garden centre. They had stockpiled 15,000 litres of derv for their lorries to run on during the fuel strikes a few years back. Trouble was the shortages never occured as they imagined and the fuel sat their for much longer than they had planned. They called me out when problems with their fleet pointed to the fuel. It was full of this bacterial growth and had started to emulsify! An expensive mistake as it was all scrapped.

but the point i think was to get to the fuel station just after the tanker is there, i cannot see a few days/weeks making any difference at all

[DaveC]

According to a post I read from a tanker driver who drove the lorries for various companies the way it works is:

All the tankers fill up with raw petrol of the appropriate octane from exactly the same source then they move to another nozzle which dumps in company specific additives - then it's off to the pumps.

[beemerbird]

Originally Posted by Gibbo

Helen, to get the ball rolling again.

Always used Super in my Boxster as I thought it was worth it and Porsche said to use it.
Used super for about a month in z4 could tell no diff. mpg or performance.
Always use std. in me diesel.
Never use supermarket fuel as I have heard less aditives but might be old wives tail
Try to use a busy garage as fuel apparently is best when fresh.

If I owned a cayman S I think I may go with regular and give it a super fill up 1 in 4 maybe. I would deffo run a couple of tanks of super through it to see if you feel any diff. or better mpg.

Or the other way of looking at it is.

Super 3p more a litre for you 11,000 miles is £75 quid a year difference. Surely you can give up a pair of Jimmy Choo's for a drop of the hard stuff.

Cheers Gibbo, think I'll try a couple of tanks of the super stuff and see how she goes.

Bloke in a Ferrari nodded at me today, then drowned me out when he accelerated - wow what a noise. Not sure which model it was though. Bet he was running on super unleaded.

How did you know I was looking for some more summer shoes My favourites are J Frazer and I can always find size 4 (must be alot of women with big feet out there).

[ShereKhan]

Originally Posted by beemerbird

As fuel appears to be 'topical' at the moment, wondered what your thoughts were on whether I should run the Cayman permanently on super unleaded or just occasionally?

The manual clearly states that it will happily run on 95 octane unleaded as the OBC adjusts the timing accordingly. However, as per BMW manuals, they CLAIM best performance and MPG will be gained by using 98 octane fuel.

Any thoughts pse. guys. Thanks.

You would have thought the Si is made to run on 98+ but for some reason BMW recommend 95 not 98 as it isn't tuned for 98+

When I have run on 98+ the acceleration is a lot smoother and the drive around town is less jerky. It also makes more noise when revving hard.

[beemerbird]

Originally Posted by ShereKhan

You would have thought the Si is made to run on 98+ but for some reason BMW recommend 95 not 98 as it isn't tuned for 98+

When I have run on 98+ the acceleration is a lot smoother and the drive around town is less jerky. It also makes more noise when revving hard.

The BMW manual on my 330i recommended 98 octane for 'optimum performance and fuel economy'. I agree with you, the engine did run more smoothly and had a 'slight' improvement in responsiveness. The biggest, noticeable difference was in fuel consumption, a stunning 1 or 2 mpg gain. Wow.

[Gibbo]

Originally Posted by beemerbird

The BMW manual on my 330i recommended 98 octane for 'optimum performance and fuel economy'. I agree with you, the engine did run more smoothly and had a 'slight' improvement in responsiveness. The biggest, noticeable difference was in fuel consumption, a stunning 1 or 2 mpg gain. Wow.

It only needs that to pay for itself. Get you abacus out again.

[M3-FAST]

My last three cars have all run on super unleaded

I had a (brand new at the time 03 reg) celica T-sport 190bhp - this asked for 98 octane and it made a very noticeable difference. The engine came alive at 6500RPM with a definite kick all the way through to just over 8000RPM. With 95 RON fuel in it felt very dull and lacking. The kick was not as severe as with 98 RON. Not sure about mpg cos as the engine ran better, it got caned more

My last car was an 05 plate (again new) Audi A4 S-line quattro 2.0T petrol. Again, Audi recommended 98RON and whilst the gains were not as obvious as in the high revving jap engine, it still felt far smoother and mid range acceleration was improved. I had a period of a month or two of usin 95RON and the car started to feel very dull! I popped a tank of Shell Super Duper in adn it really gave it some life!

The Beemer seems less noticeable though TBH. Still often use BP Ultimate but not sure it really shows any difference - maybe a little less hesitant sometimes?

I think if the manufacturer recommends it, then use it. After all the engine is gonna be optimised and timed to use it.

As for your Porsche Helen, I would say a no-brainer. It is a performance engine and if Porsche have optimised the timing to run at 98RON then it defo gonna be better than having it automatically retard itself to run at 95RON?

ALL imo of course!!

Paul

[dazzapb]

BB i was away on Holiday in carribean I missed all the drama!, congrats on Cayman S, can I be so bold to ask if you got a reasonable trade in offer on the 335d?

As re RON 98, IMO its worth it, in the 335i the manual states you should use it, and the car's engine knock control can sense the better fuel. Maybe its placebo but the car seems to run better on 99 RON than regular 95

Bear in mind that BP is 97 whilst tesco and Shell are 99

[beemerbird]

Originally Posted by Gibbo

It only needs that to pay for itself. Get you abacus out again.

Yeah good point Peter. I've 'made like the constipated accountant and worked it out with a pencil'

Originally Posted by redE93cab

My last three cars have all run on super unleaded

I think if the manufacturer recommends it, then use it. After all the engine is gonna be optimised and timed to use it.

As for your Porsche Helen, I would say a no-brainer. It is a performance engine and if Porsche have optimised the timing to run at 98RON then it defo gonna be better than having it automatically retard itself to run at 95RON?

ALL imo of course!!

Paul

No, that's a fair point Paul - cheers.

Originally Posted by dazzapb

BB i was away on Holiday in carribean I missed all the drama!, congrats on Cayman S, can I be so bold to ask if you got a reasonable trade in offer on the 335d?

As re RON 98, IMO its worth it, in the 335i the manual states you should use it, and the car's engine knock control can sense the better fuel. Maybe its placebo but the car seems to run better on 99 RON than regular 95

Bear in mind that BP is 97 whilst tesco and Shell are 99

Hi, hope you had a good holiday. The trade in on the 335d was roughly what I'd expected TBH after doing some homework before I went to the OPC, so no real surprise. They actually offered a bit more than I was expecting but then of course there is their 'mark up' on the Porsche. The price to change was my main concern and other things I got 'thrown in' as part of the deal. I filled up this morning with a tank of the 'good stuff' from Shell and after a few miles, I would say the engine is more responsive and that bit 'crisper'. See how the rest of the tank full goes (won't last long), and I'll take it from there.