I got a brim-to-brim average of 46.29 on V-Power compared with 45.12 on Fuelsave.
As a scientist I would suggest that one brim-to-brim difference like this is within experimental error, especially allowing for other variables which could affect your consumption. It may be reasonable to assume a small improvement of (say) 2.5 ± 2 %. Certainly not enough to pay for the extra cost. EDIT - even over 6 months suggests that seasonal weather will have changed quite a bit.
Edited by Andrew-T on 25/01/2018 at 09:31
|
|
The EN standards for diesel and petrol require a certain level of detergents, so even cheap supermarket fuel gets detergents.
Whether the increased amount of detergent actually improves and engine in good condition to start with, has never been independently and publicly tested.
My 2000 Astra 1.8 did a 100,000 miles on Mobil 1 0W-40 oil and Asda Smartprice petrol - after the the first oil change, it always ran sweeter than when new with HCs showing zero on annual MoT tests.
|
|
|
|
It was 6 months on each fuel - i.e. August to Feb on one fuel, Feb to August on the other. Wide enough time span on each fuel to reduce the impact of ambient temps, etc. Also my driving patterns were predictable and consistent.
|
|
You cant say for certain there were the same number of cold days with each fuel. Feb-Aug you're only really getting two weeks of really cold weather (it rarely snows heavily after valentines day I find).
|
|
I get a variation year on year so I'm sceptical of any consumption figures.
|
|
|
You cant say for certain there were the same number of cold days with each fuel. Feb-Aug you're only really getting two weeks of really cold weather (it rarely snows heavily after valentines day I find).
No, I can't say for certain about the number of cold days.
What I can say for certain is, in that particular car, with my driving patterns, over a period of 6 months exclusive usage, superdiesel did not deliver a significant enough benefit to justify the extra cost during my ownership.
|
|
Clearly it didn't. I use superdiesel in my V60 D4 simply because HJ told me personally that the chief engineer at Volvo had told him that that engine was designed to run on higher-grade diesel. I think there was an implied suggestion that there might have been fewer EGR problems with the D4 if people had used it. I've never had a problem, but my car is a May 2016 model and the 'fix' had just been introduced by then.
If I remember right, Craig, your V6 D3 was a manual. Your 45-46 mpg is similar to mine (D4 automatic), and pretty undistinguished for a diesel. People on here more knowledgeable than I may be able to suggest whether Euro-6-compliant diesels, like our V60s, are less economical than the old smokers which preceded them.
The new generation of efficient petrol turbos are to me the most convincing reason to get out of diesels.
Edited by Avant on 25/01/2018 at 22:52
|
Clearly it didn't. I use superdiesel in my V60 D4 simply because HJ told me personally that the chief engineer at Volvo had told him that that engine was designed to run on higher-grade diesel. I think there was an implied suggestion that there might have been fewer EGR problems with the D4 if people had used it. I've never had a problem, but my car is a May 2016 model and the 'fix' had just been introduced by then.
If I remember right, Craig, your V6 D3 was a manual. Your 45-46 mpg is similar to mine (D4 automatic), and pretty undistinguished for a diesel. People on here more knowledgeable than I may be able to suggest whether Euro-6-compliant diesels, like our V60s, are less economical than the old smokers which preceded them.
The new generation of efficient petrol turbos are to me the most convincing reason to get out of diesels.
Yes, both the D3 and my most recent D4 VEA were manuals. For what it's worth, the D4 averaged 46.4mpg during my 3 years and 31,000 miles of ownership. As the mileage shows, most of my usage was shorter trips, typically less than 10 miles.
My old Passat PD130 (Euro 3, so no DPF etc) used to give about the same average economy. However, while the Passat was more economical on long trips (it would often give genuine 50+mpg tankfuls if I was doing motorway miles), it was much worse than the Volvo in winter months with short trips etc.
|
|
|
|
|
It was 6 months on each fuel - i.e. August to Feb on one fuel, Feb to August on the other. Wide enough time span on each fuel to reduce the impact of ambient temps, etc. Also my driving patterns were predictable and consistent.
So, ignoring the obvious differences in temperatures and uses of heaters/lights etc, one was mostly winter diesel, and the other mostly summer.
|
It was 6 months on each fuel - i.e. August to Feb on one fuel, Feb to August on the other. Wide enough time span on each fuel to reduce the impact of ambient temps, etc. Also my driving patterns were predictable and consistent.
So, ignoring the obvious differences in temperatures and uses of heaters/lights etc, one was mostly winter diesel, and the other mostly summer.
Winter diesel has a slightly lower calorific value, so will itself give slightly worse consumption.
|
|
<< Winter diesel has a slightly lower calorific value, so will itself give slightly worse consumption. >>
Would that be detectable in the present experiment? A compensating factor is that in winter the fuel will be colder so a bit denser. As it's sold by volume you get a few more grams for your litre. Calorific values are quoted by weight I think? :-)
|
<< Winter diesel has a slightly lower calorific value, so will itself give slightly worse consumption. >>
Would that be detectable in the present experiment? A compensating factor is that in winter the fuel will be colder so a bit denser. As it's sold by volume you get a few more grams for your litre. Calorific values are quoted by weight I think? :-)
Underground fuel tanks at filling stations don't get as cold in winter or as hot in summer
|
<< Winter diesel has a slightly lower calorific value, so will itself give slightly worse consumption. >>
Would that be detectable in the present experiment? A compensating factor is that in winter the fuel will be colder so a bit denser. As it's sold by volume you get a few more grams for your litre. Calorific values are quoted by weight I think? :-)
Underground fuel tanks at filling stations don't get as cold in winter or as hot in summer
Cold winter weather makes much more of a difference with petrol though, as less of it evaporates when you're filling up and thus you get a bit more fuel for your money. Diesel is far less susceptible to this so I doubt if it will make as much of a difference.
|
|
I don't think evaporation is significant. Petrol is denser when it is cold so you are getting more petrol molecules per litre.
|
|
|
|
|
Over the last few years I have notices my diesels have worse fuel consumption during the cold months. It is quite noticable even on the car's onboard computer.
|
|
|
|
|
So, ignoring the obvious differences in temperatures and uses of heaters/lights etc, one was mostly winter diesel, and the other mostly summer.
It was a Volvo, so the lights are on all the time anyway. And I keep the heater controls on 21 degrees pretty much all the time, apart from hot days when I'll use the aircon (which will use more fuel than just the conventional heater).
Also, if you read my post again, you'll see that the 6,000 miles with a greater proportion of winter diesel (i.e. between August - Feb) was on the conventional 'FuelSave' stuff. So if you take that line of discussion, V-Power should have demonstrated a larger economy saving.
As mentioned previously, I cannot make any claims about better internal engine cleanliness from using V-Power. But in that engine - a modern high-pressure common-rail diesel with DPF etc - it made only a marginal difference to economy.
|
|
|
|
|
I've run my Mazda3 petrol for (as yet) on Shell V-Power since the summer (low total mileage, but normally decent length journeys, including my normal holiday to the SW) and only really noticed a small (few percentage points in the 3-5% range) increase in mpg over a similar usage pattern in previous years.
The problem I would have is that whilst the price difference over Shell's own (or a 'brand' competitor) is normally about 5%, they themselves are the same again more expensive than the standard UL petrol sold in the supermarket filling stations. My views generally on the subject are:
If you own a car that has been used and maintained sympathetically (including using it enough on longer trips, with the occasional 'Italian tune up' to get rid of any accumulated crud, and for diesels, regular enough at the required speed to passively/actively regen the DPF) throughout its life, I don't think using the branded superfuels will do that much good to the engine. I'd personally rather once a year buy (when its on offer) a proven fuel injector cleaner (use by adding shots to each tank of fuel for a while) as well as the above and keep the car well-lubricated with good quality engine oil.
If you have bought a car recently that you aren't sure about its previous usage history (e.g. not sure if a low mileage example has done mainly short trips that puts more strain on engine/exhaust components or just less, but longer ones [like mine] that is nowhere near as bad), definitely hasn't been looked after so well, is quite old or you know will be predominantly used for short trips/in urban areas, then, as well as looking after the general maintenance and driving it sympathetically, using superfuels is probably worthwhile doing, at least for a while as the car is whipped into shape, or once a month or so to help clear out the gunk.
I suspect the course of action generally is also very much dependent upon the car itself - some appear to be more hardy in general (at taking abuse/poor treatment [in terms of maintenance or just as a result of their age]), including whether the car is actually tuned for use of superfuels (mainly higher-performance petrol-engined cars) and may make far better use of them than the likes of my bog-standard car.
Other than helping with DPF regens and fuel injectors themselves, it seems that the benefits of the fuel cleaning the backs of valves is less useful for modern cars, given most are now (petrols included) direct injection into the chamber and bypass spraying the backs of the valves altogether. From reading other threads and opinions on other sites, it seems that many people think there is some (though to what degree I am unsure) benefit in still using this. I've seen the flashy videos on the fuel firms websites about the superfuels 'cleaning' injectors, but I am less convinced about their claims (more degree than anything else) as I've yet to find the actual (and hopefully independent) research findings in report form to back them up.
I personally am going to probably go back to just using regular UL petrol from the supermarkets given my usage type (I shy away from doing regular short trips) and give the car a once-a-year 4-shot dose of Redex, perhaps with a treat of V-Power when I go on holiday if I can afford it. Far more cost-effective in my view if you're already looking after the car well.
|
|
Regarding ditect injection, clearly the inlet valves don't get washed by the incoming charge. But they do by the reciculated exhaust gases (hence presumably the 'varnish' build up on some GDI engines). Anyhing that promotes better combustion should help to reduce build up
|
Regarding ditect injection, clearly the inlet valves don't get washed by the incoming charge. But they do by the reciculated exhaust gases (hence presumably the 'varnish' build up on some GDI engines). Anyhing that promotes better combustion should help to reduce build up
Yep - I think that's why some people were still still saying that the higher-detergent fuels did have some, though far more limited, beneficial effects. There's a YT report by Aussie journo (and engineer) John Cadogan about this if I recall correctly saying much the same.
As regards 'better' combustion, this is aparently a myth (see same report and others from John Cadogan on YT) - the higher octane rating make absolutely no difference to the amount of residues accumulated during the combustion process, but the cleaning agents in V-Power and equivalents from the branded makes are included to help clean them off, hence why the 'old' way of fuel injection makes far more of a difference to cleaning the valves than on GDI engine, if I'm interpreting the reports/other BRers comments correctly.
The YT reports I referred to are linked below:
youtu.be/La2Rt-_FL8E
youtu.be/5fKxLOTVEnI
|
|
Point is I think that cleaner injectors result in better combustion.
|
I used to work in the fuel and oil additive industry a few years ago. We ran field test vehicles, the engines of which were stripped down after every period of testing. (Mercs, fords, audis VWs amongst others)
I have seen in the flesh the difference a high quality additive package makes., especially for keeping inlet valves and injectors clean.
The expensive part of the additive is the detergent, which has to be heat stable. The inlet valves of the Mercs typically ran at 200C, whereas the slim valves of the VW polo were closer to 400C.
Premium(V power, ultimate etc) fuels will have a good quality additive dosed at a clean up dose. Regular fuels will have a keep clean dose.
Hope this is of help.
|
I used to work in the fuel and oil additive industry a few years ago. We ran field test vehicles, the engines of which were stripped down after every period of testing. (Mercs, fords, audis VWs amongst others) I have seen in the flesh the difference a high quality additive package makes., especially for keeping inlet valves and injectors clean. The expensive part of the additive is the detergent, which has to be heat stable. The inlet valves of the Mercs typically ran at 200C, whereas the slim valves of the VW polo were closer to 400C. Premium(V power, ultimate etc) fuels will have a good quality additive dosed at a clean up dose. Regular fuels will have a keep clean dose. Hope this is of help.
This seems to confirm what I found out during my research (though limited) before and during my 'experiment'. Is there any published research that's available?
|
|
|
Exactly the kind of info I’m after, though I’d love more detail.
I finally found a reasonable study, commissioned by Tesco but run independently at Milbrook. You can download the full report from this page
www.tescopfs.com/our-fuels/tesco-momentum99
The high level
Shell standard and premium VS the same from Tesco, compared accross various efficiency and deposition tests.
8 cars tested
Efficiency gains are car dependent, but are not sufficient to justify costs
Only vpower reduced deposits (all the others saw gains in some way)
The only concern for me is that I have a 325i (which is one of the cars on test), and is direct injection: not sure if that reduces the benefit. However, this was just about enough to get me into premium fuel.
I’m astounded that some of the big fleet vehicles haven’t been through something like this (RAC, AA, Police), I thought I’d find data easy to come by, but it seems not.
|
I’m astounded that some of the big fleet vehicles haven’t been through something like this (RAC, AA, Police), I thought I’d find data easy to come by, but it seems not.
I suppose it depends upon whether any effects (I haven't read the report as yet, though will do later) of having the extra detergents on reliability are short, medium or long term. Many fleets don't keep their cars more than 3-4 years, and firms like AA and RAC may not own the vans as I thought their breakdown staff are franchisees and so own the vehciles themselves or at least rent them. From the research I'd done before, it seems that vehicles that aren't abused and serviced to a high standard will last longer, but that won't make much of a difference to the owner who gets rid of it after 3 years (from new) or so.
To a private buyer who wishes to keep it for over 10 years (much more likely to be a retired person who doesn't do a lot of mileage), then it might be a cost worth bearing, if the circumstances are right (pointless if you own a car not known for decent corrosion protection). Even though I've owned my car for 12 years from new, I certainly couldn't afford (at the present time at least) the extra 7% increase in cost of using the branded superfuels (including taking into account mpg gains).
Thanks for finding this report BTW.
Edited by Engineer Andy on 27/01/2018 at 10:42
|
|
|
|
|
I honestly don't think there's any point in redex.
|
I honestly don't think there's any point in redex.
Many users appear to give it good reviews. Whether its a placebo effect or not, I'm unsure. Again, it would be good for them to publish independent tests for a range of vehicles and usages (including engines that are used on motorways vs low mileage urban/short trip usage). One thing I did find was slightly lower user review scores (admitedly on Halfords website) for the diesel version vs the petrol one though only 4* vs 5*, so not that bad really.
Again, like superfuels with extra detergent additives, a lot will depend upon how well the car has been used and looked after before using the stuff - so older, abused and poorly maintained cars will actually be helped MORE than those who aren't.
|
|
I would think you'd be better filling with a tank of premium fuel every so often it would be cheaper.
|
I would think you'd be better filling with a tank of premium fuel every so often it would be cheaper.
One 4-dose bottle of Redex used per year (£4-£5 when on offer) and 2-3 fill ups with Shell V-Power on holiday (about £5 extra per fill up over 95Ron from supermarkets) against £5 extra x5 (let alone more) or so fill ups over a year is still cheaper. I personally don't do much in the way of short journeys and so my engine is likely relatively free of gunk and corrosion, even though in many years my annual mileage has been quite low.
I agree with you that what you suggest is more worthwhile if you predominantly do short journeys and/or the car has had more than one owner and it's usage history isn't known, as I stated in my earlier comments.
|
|
|
|
I honestly don't think there's any point in redex.
I think it depends on the car. On my old diesel I used to put about 1:50 of two stroke oil into the diesel to good effect. If you're going to do this it needs to be mineral oil. I used to buy 500ml at morrisons for 1.99.
I'm now running a Euro 6 diesel, so have stopped the practice.
|
|
1:50? 2 x 500ml bottles per 50l. fill?
It must have been like the Admiral Graf Spee laying smoke while making for Montevideo.
|
|
I have run my Astra 1.6 automatic for 12yrs covering 54k miles using 95 octane for odd years and 97 for even years. The data shows a consistent behaviour of consumption after three years and 15k miles. Summer months average 44mpg and winter 40mpg with the same data distribution for each octane with overall consumption for each at 42mpg. For this combination of engine type and gearbox and my usage there appears to be no advantage using 97 octane. Accountants might find the following observations irrelevant. When using 97 octane the auto neutral function is more oily click than mechanical thump and the gearchange is smoother in the lower ratios with intake noise on gentle acceleration reduced and the flat spot at 2000 rpm barely noticeable. These changes take place after roughly two tankfulls of 97 and return to normal after one of 95. This might suggest a combination of cleaning effect and smoother combustion on 97.
|
I have run my Astra 1.6 automatic for 12yrs covering 54k miles using 95 octane for odd years and 97 for even years. The data shows a consistent behaviour of consumption after three years and 15k miles. Summer months average 44mpg and winter 40mpg with the same data distribution for each octane with overall consumption for each at 42mpg. For this combination of engine type and gearbox and my usage there appears to be no advantage using 97 octane. Accountants might find the following observations irrelevant. When using 97 octane the auto neutral function is more oily click than mechanical thump and the gearchange is smoother in the lower ratios with intake noise on gentle acceleration reduced and the flat spot at 2000 rpm barely noticeable. These changes take place after roughly two tankfulls of 97 and return to normal after one of 95. This might suggest a combination of cleaning effect and smoother combustion on 97.
Were you using the supermarket 97 Ron (including the equivalent higher Octane fuel from Tesco), 'branded' superunleaded (e.g. from Shell, BP or suchlike) which specifically has more additives (detergents) than the 'unbranded' stuff (not added when its emptied from the tanker on delivery to the forecourt) or a combination of both?
It appears as though the likes of BP, Texaco, Esso and especially Shell (very vocal in their advertising the 'benefits') make a big play of the EXTRA fuel additives, mainly detergents, that they use that are likely NOT to be added to fuels, even the high octane ones, that are sold at the supermarket filling stations.
It could be that if you have never (or rarely) have used the branded superfuels with the extra detergents, and just the (for want of a better term) 'bog standard' superunleaded, then any cleaning effect would be negligable, or if you look after the car well (getting 42mpg [even on the fuel computer] out of a 1.6 petrol auto that's 12 years old is excellent for that size of car - I can only manage 41.5 from my similarly-aged Mazda3 1.6 petrol manual [63k miles], and I'm light-footed), the first year of using the superunleaded (if you bought the car secondhand) might've cleaned out all the gunk etc (especially from the fuel injectors) and as such hasn't been needed since.
As per your comments, you may find wear to be lower when using the superunleaded, especially the branded stuff with the extra detergents, corrosion inhibitors, etc
|
|
|
|
My old Peugeot 306 HDI ran smoother on premium diesel. Even my ex noticed it.
|
|
The fuel used throughout has been esso and always from a busy station on a main road. I stuck with esso after much experimenting with my Mk6 escort 1.6S manual. Shell optimax was the favourite amongst the track day crowd and I used it for several yearly periods on the escort but the data is inconclusive. For the Astra I decided to stick to one petrol supplier for the long term. Regarding additives I have tried redex and millers adding the recommended amount at each tankfull of 95 for one year each. There was no change in mpg for either but millers does seem to make the engine run very slightly smoother but not as smooth as when running on 97. I have used additives on previous old bangers with success. My conclusion is that if you buy a car new and run it in correctly then change the oil annually and give it a motorway blast once a week you are unlikely to get the gum buildup that additves are designed to remove. I would recommend 97 for someone pottering around town and for the enthusiast if he can feel the difference.
|
The fuel used throughout has been esso and always from a busy station on a main road. I stuck with esso after much experimenting with my Mk6 escort 1.6S manual. Shell optimax was the favourite amongst the track day crowd and I used it for several yearly periods on the escort but the data is inconclusive. For the Astra I decided to stick to one petrol supplier for the long term. Regarding additives I have tried redex and millers adding the recommended amount at each tankfull of 95 for one year each. There was no change in mpg for either but millers does seem to make the engine run very slightly smoother but not as smooth as when running on 97. I have used additives on previous old bangers with success. My conclusion is that if you buy a car new and run it in correctly then change the oil annually and give it a motorway blast once a week you are unlikely to get the gum buildup that additves are designed to remove. I would recommend 97 for someone pottering around town and for the enthusiast if he can feel the difference.
My thoughts as well - other than a small increase in mpg for petrol-engined cars (that have a knock sensor) and a perhaps slight improvemence in the smoothness of the engine performance (both petrol and diesel, including the removal [to a degree] of power curve flat spots), nothing should change as these superfuels are designed to clean engines clogged up with gunk; normal grade fuels, if the car is used sympathetically (i.e. not on repeated short runs from cold or not well maintained), are more than sufficient for the vast majority of cars save high performance petrol-engined cars that the manufacturers recommend to use superunleaded petrol. Note that 'super' diesel is, if I recall correctly, not a higher cetane rating, but just has more detergents etc in it.
Given I follow the above usage and maintenance rules, then I may not even need to use the Redex (or 97Ron+) even once a year, maybe every 3 years just for one go (hence why I think Redex or similar are more cost effective), as the difference in mpg is more than outweighed by the significantly extra cost of the fuel, even at supermarkets (never mind branded filling stations which the difference is even greater).
|
|
|
|
|
|
|
|
|
