Whatcar have carried out a study (read it at whatcar.co.uk) on Superfuels which concludes many of them do nothing in terms of mpg and acceleration times.
Looking at the results for a 1.6 Focus, Total and Esso 97 octane fuels come out above Shell V power for improvements in acceleration....which is what I found when I switched from shell to total...
Worth a look anyway....
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Good post especially since we have all been talking about fuel recently here
I dont care too much about economy or performance increases, my car is fast enough :) I am more interested in the extra additives and "components" that come with premium fuels.
Especially in diesel where the result of combustion can leave soot and deposits in the oil/engine and general parts of your car - something which the article didn't touch on. I mainly use premium fuel, in my case V-Power diesel purely for its cleaning benefits. I trust that it does help and the director of Fuel Additive Science in that article says that premium fuels do contain higher concentrations of the additives. I really didnt expect a bit of fuel to give me any more performance or MPG 2bh.
Long term who knows, i maybe a sucker but for an extra £3 per fill-up I'm prepared to believe in the added cleaning benefits it could bring to my diesel engine.
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Fifth Gear also ran a test of different fuels in three cars a Renault Clio, a Golf GTI and a Subaru Impreza WRX STI. Results below:
tinyurl.com/287hhe
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Interestingly, the oil companies always repeat the same message "Our fuel is the best and our tests prove it", but they never supply supply the evidence!
Odd that!
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They never say the best.. advertising standards and all that...
madf
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& didn't WhatCar always proclaim their roadtests, or certainly a number of featured vehicles were run on BP premium fuels.
Is this no longer the case, as it might not be worth it!!??
VB
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Well, I can assure you all that I get at least 10mpg more with BP Ultimate and shell V Power than with normal petrol.
I'm typically getting 45mpg and on several occasions exceeding 50mpg with a 1996 Suzuki Swift automatic with the 993cc three cylinder engine. I've even managed the 45mpg figure on a long run with the boot crammed with luggage, myself, the wife, both kids on board and a few odd bags squashed in amongst their feet, so a heavy load. Same journey with just myself and an empty boot averaged 52.5mpg with a very strong headwind a few months earlier.
The previous owner - my father in law - could never get better than 30mpg / 35 mpg out of it with ordinary unleaded.
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Not convinced on any performance/economy increase, comparing BP ultimate to Tesco 95-RON bog-standard unleaded. Never had a problem with Tesco petrol. Interestingly, I filled up with branded unleaded last time and the performance has been dire ever since (not saying which brand but they're well-known). Might some of the oil companies be selling rubbish as "normal" petrol, to make the increase more noticeable when you fill up with their "super"? Or am I being too cynical there?
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Muggy - 2 different drivers for a start. I do not think you can obtain a 10 mpg improvement on your FIL's figures. This represents a 25% improvement! Even the fuel sellers only talk about "An extra 34 miles per tankful"
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snipquote
Yes you are right but then hasnt the suzuki swift only got a 3.4 gallon tank!
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Last month I decided to try this for myself, switching from Jet 95RON to Jet 98RON with the bike.
My impression was the bike picked up more cleanly from lower revs and certainly seemed to provide more drive revving very keenly all the way to the redline. I have not been able to verify this with 0-60 times, standing quarters etc. however, fuel consumption has gone from 48mpg to 51mpg on brim to brim checks.
I have since changed the oil on the bike so will check this next tankful to see if new oil makes a difference too.
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Like many here, I'm sceptical about premium fuels and increases in performance and economy. Certainly think that most of the percieved benefits are pyshcolgical. Fifth Gear, as previously mentioned, did a test on fuel additives, seemed quite scientific as well, a K series engine hooked upto a computer all done in what appeared to be lab conditions and found the addidtives they tested actually made the performance worse. OK I accept that the addidtives in premium fuel could clean the internals of your engine, whilst ok on a newer car, as the car gets older, maybe it is worthwhile leaving 'build up' where its is incase it causes problems, i.e. don't fix what isn;t broken. All personal opinion and after all how many cars get engines due fuel and lack of additives in fuel these days (apart from when supermarkets cause this I.e. the debarcle earlier in the year in the south east). OK engines of old may well have benefitted, but modern engines, not so sure, I think other things kill of cars before actual combustion problems, i.e. cam belt failure or ancilliary parts that make the repair un-economical. Personally I object to paying the price i'm charged for regular supermarket fuel, but if you are happy to pay for premium fuel then go for it, each to there own.
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EVO magazine did a test on Optimax (as it was) on three of their long term test cars. I know one was a BMW M Coupe, but I can't remember the others - they were all performance cars anyway.
The fuel economy of the cars had been carefully monitored as part of the long term test programme anyway, so that was known. They then filled the tanks with the same brew normally used, took the cars to the track, strapped on the timing gear, and ran a full set of performance tests on them. Finally, a borescope examination was done of the piston crown and combustion chamber, and the pictures saved.
Each car then ran 3 tankfuls of Optimax over its normal daily routine. A fourth tankful was added, and the cars were taken back to the track, timing gear reinstalled, and the same performance tests repeated.
All showed 0.2-0.5 second reduction in 0-60 and 0-100 mph times.
All showed a higher top speed apart from the BMW which was electronically restricted.
All showed a 2-3 mpg improvement on their daily runs.
The real selling point though was the second borescope examination. It looked like each engine had been stripped and cleaned. The difference was just remarkable.
I always ran our MX-5 on Optimax after that. I don't tend to bother with the diesels. I just use decent brand fuel and make sure they get a good thrashing regularly.
Cheers
DP
--
04 Grand Scenic 1.9 dCi Dynamique
00 Mondeo 1.8TD LX
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It looked like each engine had been stripped and cleaned. The difference was just remarkable.
That reminds me - during my 2006 MoT - and I still have the report to prove it - my swift had the rare distingtion of registering zero on the CO2 emmissions during the idling test.
If I remember, I will scan it in and e-mail it to HJ tonight.
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Yes you are right but then hasnt the suzuki swift only got a 3.4 gallon tank!
It's 8.9 gallons.
And yes, I do think some of the gain may be down to my light right foot driving style, but for the first few months when I had the car I was putting the ordinary stuff in it and I was getting more or less what my father in law got from the car.
Another factor may be that I don't leave the tank full unless I'm going to do a long trip; I fill up the night before the trip so I have as much as possible of the freshest possible petrol in the tank.
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I fill up the night before the trip so I have as much as possible of the freshest possible petrol in the tank.
That would only be true if you were filling up at the refinery otherwise it could be a couple of weeks old depending on the throughput of the petrol station.
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Toad is now on Tesco 99 octane with added Redex (rather than one of the premium brands as previously) and the peak boost pressure recorded on the Greddy gauge has gone up slightly, without any adjustment. That is a straightforward comparison of readings, and suggests some good.
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Compared to all the other associated costs, of running a vehicle, wouldn't it be a simple case of buying the highest quality fuel available, simply as a matter of course?
That way you'd at least be doing the best, to look after the purchase, without REALLY spending too much more £$£$£
Unless you run a really old banger, or a company car, where fuel purchase might be dictated, it would be my choice.
Mrs V's Mx5 has only ever had Shell Optimax/V Power, in its 4 & a bit years.
My Omega, might be not far off it's 10th birthday, but doues run smoother & gives around 23mpg more on the stuff, too.
& as the Shell sites here in Luton, mirror Asda prices, it's still not much more to pay!
VB
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I've not convinced that it's worth paying any extra for premium fuels, however I'm aware it's apparently beneficial for some engines. IIRC didn't some Vauxhalls have a plug in the engine bay that could be re-positioned if using higher octane fuel?
I was running a Vitesse back in the early '70s, that was recommended to use 100 octane. They phased it out, and it pinked like a good 'un. I retarded the timing, and richened the mixture until I lost the pinking, but it never felt the same. I think the old Rover 2200 TC of that era suffered the same problem.
I tried two consecutive tankfuls of Optimax in my '53 Almera (brim tank, record mileage, brim tank, crunch numbers), and recorded no difference whatsoever, and felt no difference in its driveability. However, I tried the same in an old 750 Panda, and I'm sure it felt more responsive, although accurate economy comparisons aren't available.
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My Shell V Power test is not yet over but I'll go back to normal Shell. The extra cost of diesel has no noticeable benefits - in anything.
There are of course badly designed engines in which it would make a difference. I include GM in that category...and Rover.
PS I saw the C5 test of petrol additives. Most appeared to contain methanol. IIRC Methanol requires more oxygen and a higher fuel flow as the energy/litre is lower than petrol. No wonder most test showed a 2% power loss as the poor fuel injection system would fuel it as petrol... So a complete waste of money...Methanol also does nasty things to seals iirc as it is aggressive..
(model engines anyone?)
madf
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