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This has got me intrigued enough to try it, at the client's expense thankfully. I certainly know that I get worse mpg in the Jag from Sainsbury's diesel than I do from my local Shell. An easy 5mpg per tank. Will be interesting to see if premium Shell improves it over standard. Mine is a 3l V6 oil burner, so whilst not exactly the most fuel efficient on the planet, isn't too bad given it's level of poke.
The best way to save money on fuel is just to drive more economically / slower!
Aint dat da troof!
Been reading about adding two stroke oil to diesel to improve performance mpg etc
http://www.disco3.co.uk/forum/topic83987.html
I have had to replace sensors twice in our MR2 both times after using sainsburys fuel , my mate a Toyota technician said both times it was due to the fuel mix. I also used Sainsburys in my celica daily driver and it didn't feel as responsive to the shell I usually use. I know this debate can run on and on but from my personal experience (maybe due to my cars both have similar engines) there's a difference between shell & sainsburys fuel .
A mate of mine spends quite a lot of time at Fawley. He reckons "everybody" there thinks Shell fuels are the best performing* (I don't think that's historical allegiance - believe Fawley's a BP place really)
*clearly they may "all" be gobshites
Hmmm might explain the drop in mpg after fiiling up at sainsburys.
I actually get worse mpg driving slightly slower/ lower rpm only a few mpg but noticable. Isnt maximum torque where the engines most efficent? Obviously this changes with load.
High octane petrol - no difference unless you have a turbo or a high compression ie actual sportscar engine.
Higher cetane diesel affects any diesel car regardless. I thought V-Power/Ultimate was higher cetane as well as cleaner? Higher cetane supposedly gives better starting, smoother running, better power and better economy.
Anecdotally, in my Passat, the fancy stuff runs a bit quieter and definitely starts better. However, starting on normal is never a problem anyway. I can't tell if there's any more power, and any improvement in economy is lost in the normal variation so I can't tell. I don't drive the same route regularly in the same conditions.
I've also noticed that normal Total diesel is pretty smooth, and doesn't cost extra.
Isnt maximum torque where the engines most efficent?
Not really - depends on loads and loads of things, including engine load. And how you define efficiency. Fuel/engine power ratio, fuel/speed or fuel/distance...?
molgrips - MemberHigh octane petrol - no difference unless you have a turbo or a high compression ie actual sportscar engine.
Or a lot of ignition advance.
honest john at the torygraph seems to think it's worth it.
My old jap import Hona Predlude use to run best on Essos posh stuff. More miles to the tank and a lot smoother. That had a knock sensor and they do have 99ron fuel over in Japan so it makes sense with that.
backinireland - when I had an old VW T4 van I heard too from other owners about using 2 stroke oil in diesel to help/improve running though I never tried it
Don't really bother with the 'posh' fuels so can't comment on them, but Sainsburys diesel is the only one where I notice the car never feels as powerful. It doesn't like running on it.
As Sui points out though adding cetane booster can be cheaper. Also worth trying - the relevant chemical is called 2-EHN or 2-ethylhexyl nitrate, which you can buy on ebay where it's vastly cheaper than Millers etc. It has a very distinctive smell, and you can smell it when you fill with V-Power diesel.
Please God, be careful with that stuff in neat form....
I was very cynical about some diesel being better than others, but in my car it's noticeable when a DPF forced regen takes place. With supermarket diesel I seem to get about 1 forced regen per tank. With standard BP or Shell I get one every few tanks. With V-power or equivalent posh diesel I hardly ever seem to get a regen, and it seems to go further on a tank although I suspect not enough to make the difference in price worth it.
Thanks for the info Sui. - May try it myself.
My Renault Diesel usually gets fed either Morrisons or Esso.
Runs lovely and smooth, with decent acceleration & MPG on Morisons, but it does have an odd smell to it when it comes out of the exhaust pipe.
Barring the smell, it's almost identical in performance as Shell / Esso.
Running on Tesco diesel, it feels a tad sluggish & MPG drops slightly, Asda diesel ( last time I tried it), car just didn't feel happy.
Chris
"the relevant chemical is called 2-EHN or 2-ethylhexyl nitrate, which you can buy on ebay where it's vastly cheaper "
surely that will just get confiscated by royal snail ?
...or maybe it's [i]just[/i] your mate who's the gobshite!A mate of mine spends quite a lot of time at Fawley. He reckons "everybody" there thinks Shell fuels are the best performing...clearly they may "all" be gobshites...
molgrips - MemberHigh octane petrol - no difference unless you have a turbo or a high compression ie actual sportscar engine.
Do you know that for sure?
birney29 - MemberThe actual, proper answer is this:
Higher octane fuels will indeed make a difference, but only if the engne has knock sensors fitted. Knock sensors allow the fueling and the detonation to be changed to make use of the higher octane fuel.
Most engines with Turbos have Knock sensors. If you have, for example, a Subaru Impreza WRX, then yes the higher octane fuel will allow the engine to generate more power.
If you have a 1.2 naturally aspirated Clio or similar, forget it.
Boggo (non-turbo) petrol Focuses have knock sensors. Be surprised if other cars didn't.
Having a knock sensor doesn't neccesarily mean that it's using that information to provide performance benefits, though. (well, OK, that's handwavey, arguably just about everything a car does is a performance benefit; but you know what I mean. There's a baseline, it could be that all the knock sensor does is retard the ignition or whatever when it detects knock, rather than increase the advance (or boost, or whatevs) when it detects it has headroom.
not diesel.. but i use shell V-Power unleaded in my car.. 1.6 Citroen Saxo..
noticed absolutely no difference in performance..
but the average MPG jumped from 42 to 46..! this is compared to normal shell petrol.. supermarket stuff was lower than 42..
It worked out at quite a bit of a saving in total fuel costs over the year 🙂
Please God, be careful with that stuff in neat form....
Why? Seriuos question.
Regarding high octane pertol, I was under the impression that it's reduced volatility enables you to run a higher compression ratio which gives mite power and economy. But in order to run these engines on normal petrol as well, they have to retard ignition to prevent knock. So they effectively detune themselves. But given the high octane stuff they will sense this and put themselves back in a more efficient setup.
This used to be only sports cars that did this, but maybe some more modern engines so it for economy reasons, dunno. 5th gear tsted this many years ago now.
Spacehopper - that could have been the result of cleaning your engine.
My company runs a fleet of 2,500 yellow Transits. These are all fitted with telematic systems that record very accurately all engine parameters including fuel consumption.
A couple of years ago about 100 of these were run on exclusively V power diesel for 1 year, the rest of us used the normal stuff.
The idea was to test the claims of better economy in the real world and see if the extra cost of the fuel was worth it.
They never published the results of the test but everybody is now back to running standard diesel so you can draw your own conclusions!
Its the fuel.
I've dropped back to the normal fuel a couple of times to test and the results always the same..
i always fill up with a full tank from running on completley empty.. and then did three tanks full in a row of the normal shell.
normal shell 42 mpg ish
V-Power 46mpg ish
He's sensible and quite a sceptic generally, and told the story in a relatively disbelieving way - like there was a massive conspiracy afootRusty Shackleford - Member
A mate of mine spends quite a lot of time at Fawley. He reckons "everybody" there thinks Shell fuels are the best performing...clearly they may "all" be gobshites...
...or maybe it's just your mate who's the gobshite!
The idea was to test the claims of better economy in the real world and see if the extra cost of the fuel was worth it.
In my opinion, the fancy diesel is better, but not better enough to be worth it. I'd choose Shell or Total regular given the choice.
Mol, it makes you go a bit gaga when you breath the fumes in... not in a good way either..
Huge difference, my xtrail which I had from new back in 2004 had over 200,000 on the clock and the smoke coming from the exhaust was dangerous to one & all plus the acceleration was becoming ever more snail like so I thought what the hell lets give it go.
The first change was less and less exhaust smoke and then bit by bit the acceleration improved and the mpg was noticeably better. My xtrail goes this month after wonderful 10 years and 230,000 miles and its running great on posh diesel 🙂
bum, only just filled the yeti up on tesco value.
next time I'll go for the finest range
I really noticed the difference by the second tankful, I guess it takes a while to help clean system
Glad to be of service 8)