What are the real differences between supermarket and oil companies fuel

audifan

A2OC Donor
I know the refineries blend is different for companies, but can some fuel expert explain the exact differences from an unbiased point. Specifically interested in diesel but petrol would be of interest to others especially FSI owners.
 

EamonnDH

Member
The real difference is in how clean the base fuel is, and what additives they add.
Expect cheapo base fuel with higher traces of water and general bits of grot, and only the basic additives at the supermarket pump. Hopefully the opposite at the premium brand pumps.

If you dig around you can find the test results for the different fuels. For me when I was researching for which diesel fuel was best for my 3.0 TDI A5 to prevent DPF trouble I found the measure of how much ash/dirt is left after combustion most interesting. In order of best to worst leftover junk it was V-Power, BP Ultimate, Shell Regular, Texaco, then all the way down the scale to supermarket snot.

Though, with the A2s not having DPFs fitted, I really wouldn't worry too much about the fuel cleanliness etc. There's no DPF to clog, and the cleaning additives will do little to help as it's a direct injection engine so you won't wash the valves.

The 1.4 AUA petrol is, as far as I know is the only port injection motor so will benefit the cleaning, but other than that the difference is down to octane/cetane. The petrols are unlikely to see any difference with better octane, they're just not tuned up fancy motors. Diesels on the other hand will naturally take advantage of better octane and generally run a bit quieter and pick up a little quicker. Don't expect better MPG though.
 

Providence

A2OC Donor
Honest John in the Telegraph reckons that Shell VPower 99 octane can give a 10% BHP increase.

I've been running it for 18 months in my 1.4 Sport BYB and it is definitely an improvement. When I got the car it would not pick up speed at any acceptable rate under 3000 RPM. I am assuming that the combination of the clean up by the fuel and the increased octane have made the acceleration acceptable down under 2000 RPM which makes for a more relaxing drive. Coming from a 1.4TDI, I was quite shocked at the amount of gear changing I was doing!

It could be just the clean up of course and not the octane. It was on 96 000 miles and maybe had run its whole life on the grot stuff!
 

EamonnDH

Member
Honest John in the Telegraph reckons that Shell VPower 99 octane can give a 10% BHP increase.

I've been running it for 18 months in my 1.4 Sport BYB and it is definitely an improvement. When I got the car it would not pick up speed at any acceptable rate under 3000 RPM. I am assuming that the combination of the clean up by the fuel and the increased octane have made the acceleration acceptable down under 2000 RPM which makes for a more relaxing drive. Coming from a 1.4TDI, I was quite shocked at the amount of gear changing I was doing!

It could be just the clean up of course and not the octane. It was on 96 000 miles and maybe had run its whole life on the grot stuff!
I would agree there is sometimes a little gain. Though, I used to work in an office next door to Honest John, and unfortunately they don't really write anything unless paid to do so.
 

DJ 190

A2OC Donor
I've explained things regarding this topic quite a few times on this Forum. The raw fuel will be sourced from the nearest refinery, regardless of the eventual brand or whether it's from a supermarket. That means it's exactly the same quality. The tanker driver then adds at source a particular additive package to make the fuel unique. It will always be "in spec" and will do its job. However, top brands will have the latest "cutting edge" package which will keep your engine running clean and healthy. Supermarket fuel will have an earlier and inferior additive package.

David
 

Robin_Cox

Member
I've explained things regarding this topic quite a few times on this Forum. The raw fuel will be sourced from the nearest refinery, regardless of the eventual brand or whether it's from a supermarket. That means it's exactly the same quality. The tanker driver then adds at source a particular additive package to make the fuel unique. It will always be "in spec" and will do its job. However, top brands will have the latest "cutting edge" package which will keep your engine running clean and healthy. Supermarket fuel will have an earlier and inferior additive package.

David
As regards the quantity of junk, isn't that also corollary of the tanker itself? I remember probably 17 years ago here in Dundee that there was a sudden spate of expensive failures here when a tanker supplying various local supermarket petrol pumps was found to be significantly compromised with both diesel and water contamination. It was headline news. A lot of modern cars broke down and needed recovery shortly after refilling - the same week my student 2CV started running erratically rough after a Tesco fill-up (mostly on only one cylinder that could be just about overcome by dropping a gear and ) with a strong dieselly smell in the cabin when normally it would be reeking of evaporated petrol overflowing onto the cylinder head from the carb - and only cleared up after I gave it a refill of Shell after half a tank.
 

EamonnDH

Member
As regards the quantity of junk, isn't that also corollary of the tanker itself? I remember probably 17 years ago here in Dundee that there was a sudden spate of expensive failures here when a tanker supplying various local supermarket petrol pumps was found to be significantly compromised with both diesel and water contamination. It was headline news. A lot of modern cars broke down and needed recovery shortly after refilling - the same week my student 2CV started running erratically rough after a Tesco fill-up (mostly on only one cylinder that could be just about overcome by dropping a gear and ) with a strong dieselly smell in the cabin when normally it would be reeking of evaporated petrol overflowing onto the cylinder head from the carb - and only cleared up after I gave it a refill of Shell after half a tank.
That was due to a contamination at a particular supplier. I have don't have the name to hand, but if I remember correctly the issue was contamination with sulphur or something similar which was destroying the fuel system of petrol cars. What the guy above said about "nearest refinery" isn't entirely true. As demonstrated by the contamination scandal which only effect certain brands, they do not share a common supply.
Yes, most of the supermarkets all buy from the same refinery(s), but the bigger brands absolutely do use their own refineries and base fuels. You won't see a BP truck coming of a Shell refinery.
 

PlasticMac

Member
Tankers fill at a terminal, which is rarely located at a refinery. Most terminals are what's termed dry, which means little or no on site storage. Fuel comes to these terminals via underground pipeline, from the refinery, or from the port if the refinery is not in UK. Major brands have their own terminal, which is not shared. Supermarkets do not, they use a shared anonymous terminal, which are fed from bulk storage depots. The fuel is also anonymous, and is sourced from those refiners (there aren't many, and they're not all in UK) via the market. Additives are added via an injector pump, not unlike the PD!
As I've said before, supermarkets are not philanthropic organisations, the fuel they sell is cheaper, because it's sourced on the open market, and because the additives are basic.
Mac.
 

andrewparkeruk

A2OC Donor
@DJ 190 David, in threads like this it might help others if you state your background.
All the best, Andrew

PS that doesn’t mean I am disregarding statements by others, just that I have met David and know his background
 

DJ 190

A2OC Donor
@DJ 190 David, in threads like this it might help others if you state your background.
All the best, Andrew

PS that doesn’t mean I am disregarding statements by others, just that I have met David and know his background
I'm an Ex-Shell employee. I worked for Shell Research, Thornton (Latterly Shell Global Solutions) I was part of the team that developed Shell Optimax. I had my own exclusive laboratory.

David
 

PlasticMac

Member
Around 40 years in retail petroleum, with equipment manufacturers, petrol pumps, bulk fuel metering and additive dosing, forecourt systems etc, Mainly in tech support (who you gonna call?).
However, I've been retired a while, so maybe a bit rusty!
Mac.
 

audifan

A2OC Donor
@PlasticMac And I thought the additives were supposed to stop rust.:D
On a serious note both @DJ 190 and @PlasticMac are the type of experts I will listen to. Now all I need to know is exactly what additives are added to which fuels so I can rank the companies in order of preference v cost. Thanks both. Insider knowledge removes all the advertising "fluff".
 

EamonnDH

Member
Your best optional is go Google digging for their spec sheets, though you might only find slightly out of date ones.
 

PlasticMac

Member
@PlasticMac And I thought the additives were supposed to stop rust.:D
On a serious note both @DJ 190 and @PlasticMac are the type of experts I will listen to. Now all I need to know is exactly what additives are added to which fuels so I can rank the companies in order of preference v cost. Thanks both. Insider knowledge removes all the advertising "fluff".
To keep the rust at bay, use WD-40, a tea spoonful, after meals.
(This is not a recommendation to use WD-40 as a dietary supplement).
I'll stick with Shell Nitro in my FSI, always used Shell, right back to the 5 star in the Norton. Get your gas, electricity, or broadband from Shell, and you get 3% off the first 60 litres of fuel each month. You need a Shell Go account, which is free. .
Mac.
 

philward

A2OC Donor
Diesel cars that I own and owned have never been run on anything other than supermarket fuel, I have a long drive to get branded fuel. They have all been fine and gone to high mileage. I had a low compression 1.8 lt golf that I ran on supermarket fuel, it was fine went to high mileage too.
High compression engined petrol cars I do not fill at the local supermarket which only sells standard petrol. I shop around for high octane petrol, Sainsburys is fine and the best Tesco 99 octane. I don't see the point in paying extra for branded fuel, even if I could get it.
 

EamonnDH

Member
Diesel cars that I own and owned have never been run on anything other than supermarket fuel, I have a long drive to get branded fuel. They have all been fine and gone to high mileage. I had a low compression 1.8 lt golf that I ran on supermarket fuel, it was fine went to high mileage too.
High compression engined petrol cars I do not fill at the local supermarket which only sells standard petrol. I shop around for high octane petrol, Sainsburys is fine and the best Tesco 99 octane. I don't see the point in paying extra for branded fuel, even if I could get it.
In the sense of diesel, stuff like Shell's diesel V-Power is provably nicer to DPFs. Otherwise, yeah go for it if you don't have a DPF.
 

Rod davis

Member
I always fill up at the supermarket. I worked a while back for Calor gas which had a vertical monopoly and was thus obliged to fill every tanker regardless of the name on it. The stuff was identical, yet there were always those who had a favorite brand. There were also a variety of names including Shell filling up with liquid fuels next door....
 

Malcyb

Member
I'm an Ex-Shell employee. I worked for Shell Research, Thornton (Latterly Shell Global Solutions) I was part of the team that developed Shell Optimax. I had my own exclusive laboratory.

David
When did you join Shell Research? My dad used to work there, a combustion expert, though I doubt your paths ever crossed since he retired in 1984. Small world!
 

DJ 190

A2OC Donor
When did you join Shell Research? My dad used to work there, a combustion expert, though I doubt your paths ever crossed since he retired in 1984. Small world!
1966 ...... I recon that I might have known him. 700 people worked there when I started. I've even got the telephone directory from the 70's/80's!

David
 
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