The actual tank may remain the same, but a "tankful" doesn't mean much since you don't know with any accuracy how full it is!  It is the lack of precision which I am commenting about, not the phraseology people use to describe their fuel consumption.

 

Which, as i mentioned, a problem no matter how you go about working it out. As i said, i did it both ways, but both ways have errors.

So you fill your tank up, drive 100 miles, then fill the tank up again to see how much fuel you used. But is this second pump accurate? Is the pressure sensor to sensitive? You may then drive another 100 miles, and again fill up to see what you used this time. But this fuel pump may be less sensitive, and allow more fuel in. OK the difference wont be large, but it still means it isnt 100% accurate.

So the lack of precision in knowing how full the tank is, effects your way as much as anybodies.

As i said, i looked at it in 2 different ways, mileage on half a tank, then the amount of fuel chucked in to work out an MPG. I then checked to make sure the mileage and MPG were there or there abouts. Ive never once claimed any way is 100% accurate, because they arent. But you can get a fairly accurate idea, and my 'fairly accurate idea' showed me that VPower is economically beneficial. As in, I saved money by using it.

I think you're all spliting hairs at this point, if you record your fueling everytime over a long period of time you'll get pretty accurate, if you do one tankful there is a margin for error yes but, its a pretty small margin.  Fuelly.com seems pretty good so, I'll give that a go when mine gets here.

 

Kinda make its difficult to analyse different fuels over short periods of time accurately yes but, then we all drive differently so, whats the point ?

 

The fuel consumption of your car, with or without any modifications you make, driven your way, with your choice of fuel WILL be different to mine.

 

Just my tupennies worth though.

 

Regards

T

Oh, and when V Power is getting you 40 to 50 miles extra per tank, you can be fairly sure that isnt all down to 'the mystical tankful'

I think you're all spliting hairs at this point, if you record your fueling everytime over a long period of time you'll get pretty accurate, if you do one tankful there is a margin for error yes but, its a pretty small margin.  Fuelly.com seems pretty good so, I'll give that a go when mine gets here.

 

Kinda make its difficult to analyse different fuels over short periods of time accurately yes but, then we all drive differently so, whats the point ?

 

The fuel consumption of your car, with or without any modifications you make, driven your way, with your choice of fuel WILL be different to mine.

 

Just my tupennies worth though.

 

Regards

T

I was purely trying to show that on one run, V Power performed better. 99% of the time i wont be checking fuel consumption. But this was one i wanted to, so did a check on it. Unfortunately it apparently wasnt accepted because of one word i used.   

I think it's wishful thinking that you'll get 40-50 extra miles from a tank just from using a different fuel...

... you fill your tank up, drive 100 miles, then fill the tank up again to see how much fuel you used. But is this second pump accurate? Is the pressure sensor to sensitive? You may then drive another 100 miles, and again fill up to see what you used this time. But this fuel pump may be less sensitive, and allow more fuel in. OK the difference wont be large, but it still means it isnt 100% accurate ...

No one said it was 100% accurate, but obviously far more accurate then quoting that mysterious and undefined quantity - a "tankfuk"!

How empty is your tank when you refill it? 

... Unfortunately it apparently wasnt accepted because of one word i used.   

No, just rather less meaningful because of the method (not the words) you used.  If you had actually measured it (the are numbers on the pump you used - that's how they know how much to charge you), you would know, instead of having to guess.

Nobody has mentioned that Vpower Nitro+ and Momenum are 99RON fuels.

 

This is a fair step up from most standard unleaded 95RON fuels.

 

I know that I don't have an Octy, I'm in a Mk2 Fabia vRS and this is a different car altogether, but they do at least recommend 98 in the fuel filler cap.

 

Please feel free to shoot this all down as irrelevant however to me it seems the two cars share a common trait, as per the above post it seems that both are optimised for 98RON fuel.

 

Having run my car on 95RON (straight from the dealer who said it didn't need 98 ), 97RON (in emmergencies, just enough to get to a shell station) from the like of Texaco and Vpower Nitro+ 99RON

 

My car doesn't like 95RON at all and this did noticeably reduce performance and gave a misfire too, 97 is marginally better in all aspects but again in small increments is even better with the Vpower Nitro+ and presume would be the same with Momentum.  This equates to a marked difference in response between 95 and 99 for me, rarely do I get the MPG benefit as I tend to feel more inclined to give the car beans

 

The ECU's are capable of adapting to differing air flows and RON rating of fuels, this happens very quickly after a few miles but usually is slower to come in as an effect as any 95/97 in the tank will naturally water down the 99 you fill with.

 

My vote is with the "why buy a performance car/hot hatch" and not get the most out of it.  To my mind if you aren't interested in pampering a vRS, maybe you should have gone for the Elegance

 

Again, feel free to dismiss any of the above on account of non Octy ownership.

(For the mathematically challenged, if you wish to quote your fuel in mpg so that it is comparable with everyone else, simply multipy litres x 0.22 to get gallons.  Really not difficult!)

or divide by 4.546 same result. :think:

No, just rather less meaningful because of the method (not the words) you used.  If you had actually measured it (the are numbers on the pump you used - that's how they know how much to charge you), you would know, instead of having to guess.

Who is guessing? This was a couple of years back, and Im not worried enough to go recording everything, so its a vague memory of what i was getting. 

 

As for my method being less meaningful. No it isnt. Its no less meaningful than your way as there are errors in both. In fact, the same errors effect both. OK it may be slightly less meaningful to you, but to me, when i was working it out, it was perfectly meaningful. OK so it doesnt tell you what the extra miles are over (because i never told you), but considering what i was trying to say, it gives you a fair idea. V Power was better, and i was better off by using it.    

 

Oh, and as mentioned, I DID IT BOTH WAYS. To check for errors. So in fact my way was more meaningful.

 a "tankfuk"!

 

A what  

I think it's wishful thinking that you'll get 40-50 extra miles from a tank just from using a different fuel...

If i remember correctly, it was 40. I had no wish to record all my findings on the off chance i would be challenged on a forum i had yet to hear of at the time. I was better off, and i know someone else who was better off. That'll do for me

How empty is your tank when you refill it? 

Who cares? I measure the miles achieved, then check what amount of fuel i put in when i do fill up. The final figure would have given you the answer, but i have no need to remember it. Its long since left my memory. 

Top program

Can i borrow one of your motors? Going to make the car electric i think! Then i wont have any inclination to say anything to start with

A what  

 

Sex in a Chieftain. 

 

Top program

Can i borrow one of your motors? Going to make the car electric i think! Then i wont have any inclination to say anything to start with

 

Ask at a certain train care depot in Ashford, I'm sure that they may have a spare EE507 motor available and at 250 hp, it'll go like brown stuff off a stick, the fuel & battery economy will be poo though..

Think you guys are totally off thread .

 

Give it a break and go elsewhere and set up another of your choosing for  your banter 

Thanks

Nobody has mentioned that Vpower Nitro+ and Momenum are 99RON fuels.

 

This is a fair step up from most standard unleaded 95RON fuels.

 

I know that I don't have an Octy, I'm in a Mk2 Fabia vRS and this is a different car altogether, but they do at least recommend 98 in the fuel filler cap.

 

Please feel free to shoot this all down as irrelevant however to me it seems the two cars share a common trait, as per the above post it seems that both are optimised for 98RON fuel.

 

Having run my car on 95RON (straight from the dealer who said it didn't need 98 ), 97RON (in emmergencies, just enough to get to a shell station) from the like of Texaco and Vpower Nitro+ 99RON

 

My car doesn't like 95RON at all and this did noticeably reduce performance and gave a misfire too, 97 is marginally better in all aspects but again in small increments is even better with the Vpower Nitro+ and presume would be the same with Momentum.  This equates to a marked difference in response between 95 and 99 for me, rarely do I get the MPG benefit as I tend to feel more inclined to give the car beans

 

The ECU's are capable of adapting to differing air flows and RON rating of fuels, this happens very quickly after a few miles but usually is slower to come in as an effect as any 95/97 in the tank will naturally water down the 99 you fill with.

 

My vote is with the "why buy a performance car/hot hatch" and not get the most out of it.  To my mind if you aren't interested in pampering a vRS, maybe you should have gone for the Elegance

 

Again, feel free to dismiss any of the above on account of non Octy ownership.

I agree with this!  Including "... why buy a performance car/hot hatch and not get the most out of it?"

Which is why I fit good tyres and check the pressures regularly, use good oil and have the car serviced properly and regularly.  

But ...

there is no point in using something just because it costs more, if the car cannot take advantage of it.  To quote from my handbook (written by people who, I believe, know more about my car than me):

"You can make unlimited use of a fuel which has a higher octane number than required by the engine.  There will, however, be no advantage gained by this in terms of engine performance and fuel consumption.

The handling, performance and life of your engine are determined to a significant extent by the quality of the fuel.  Do not use any petrol additives.  Use a fuel complying with the standard."

Their words, not mine.   

The only car I have had to use super-unleaded in was a Jap Import (JDM) Impreza WRX STI IV. The car was made to drink 100 RON fuel which was not always readily available within the UK, so I needed to add octane booster to prevent problems. Luckily I had a IV rather the weaker engined STI V's which liked to let go if they were fed normal fuel.

For every other car I have owned I have noticed no perceivable performance or economy benefits from using higher RON fuels. They were all built to run on 95 RON or lower fuels, and we're happy drinking the stuff.

Edited 17 January, 201412 yr by Orville

This is an extract from Kenya Motor Industry Association:

 

"World patterns

A survey of 50 countries from all continents shows that octane 95 (RON) is overwhelmingly the most common grade, with few countries offering lower grades and many using high grades.  Those offering only one grade use either 95 or 98.  The lowest grade premium fuel offered worldwide was 92 (India), but 95 is now being introduced in that market also."

 

From the same article "A slightly higher rating (up to 98) might offer marginal benefit to a few of the highest compression engines, but is not essential for their proper operation and would be unnecessarily expensive (with no additional benefit) to the majority." 

 

For me the above information says it's OK to use standard 95RON fuel in a VRS but to get the best out of the engine I would need to use the highest grade fuel available.

 

 Link http://www.kmi.co.ke/kmi-briefs/octane-ratings

 

My understanding is that an engine will have been designed, developed and therefore optimised for a particular octane rating, usually one which is widely available.  This optimum octane rating will normally be stated by the manufacturer. 

And that although the ECU, in response to "knock" detectors, will adjust the ignition timing if necessary to cope with fuels of lower octane rating, it will not adjust the ignition in any way to take advantage of fuel with a higher octane rating than this optimum.

So, although quite harmless, there would seem to be little if any advantage in using a fuel with a higher octane rating than the grade specified by the manufacturer.

If I have misunderstood this, I trust that someone who knws better will correct me.

As for the various fuel additives in certain "special" petrols and the supposed advantages which these confer, that is a much more uncertain area.  All I can say is that in my own experience, I have never noticed any benefit whatsoever.  That doesn't mean to say that there definitely aren't any advantges - just that I've never been able to detect them.  Similarly with supposed "inferior" supermarket fuel - works fine in my car, as one would expect.  It all complies with the same minimum standards, for which the engne was designed.  Just like aviation fuel, where (regardless of brand name) it all comes out of the same tank at an airport; and no-one takes risks with fuel in an aeroplane.

Edited 18 January, 201412 yr by Stuarted

@ Stuarted - agree with your comments regarding using 95/98 RON - pretty much what I've said I believe.

However I won't get dragged into another briskodawar over the benefits of using premium grade high octane fuel over supermarket fuels. On this I know we disagree....

Well it seems unanimous for me now. Super is better.

80mile route on the M1 using Esso unleaded = 33mpg.

Same route using Esso Super = 38mpg.

This was after 5 fill ups of Esso Super unleaded in my vRS to rid regular out of the car. Adaptive cruise was used and set at 73mpg. M1 was quiet both times will little traffic.

Question is, is the price difference worth it? My local Esso garage charges:

Unleaded = £1.25

Super unleaded = £1.35

=£5 extra for my 50l tank

50 litres = 13.2 gallons

5mpg extra *13.2 gallons = 66miles extra range with Super Unleaded.

There are flaws in my maths but it's approx 15% extra range for 7% uplift in price.

that is a clear difference farsider.  Has the car done enough miles to have loosened up though, or could the ongoing loosening have contributed to the improvement too?