Shell diesel vs supermarket diesel

Mr Pig

Active Member
Jun 17, 2015
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6 x refineries in UK producing fuel to specific standards - note that neither Shell nor the supermarkets run any of these. In 2017, supermarkets had 45% sales by volume, but only owned 18% of sites. Also look at how many sites are now owned by the major oil producers in the past 10 years.

I don't see the relevance or significance of any of this?
 

black_sheep

Active Member
Mar 10, 2013
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I don't see the relevance or significance of any of this?
It is relevant because this entire thread is about the comparison between branded fuel and supermarket fuel - whilst it may not appear relevant to some, to others I thought that some relevant open source evidence, rather than personal judgement might be of interest. It is also relevant as neither Shell nor the supermarkets produce their own fuel in UK; they are reliant on one of the 6 refineries producing the base product in addition to their blend of additives.

The first significant point is that an earlier post stated that one fuel supplier exceeds the RON level whereas another only meets it (albeit this is for petrol) and it was assumed that the same is true for cetane equivalent in diesel. If both market the same cetane or RON levels, then they will both be required to achieve this; however, neither will give away the most expensive base product for free, as this comes straight off their bottom line. The second significant point is that supermarkets sell almost half of the vehicle fuel sold in the UK, but from less than a fifth of the total number of fuel stations, which has a significant factor on the cost (distribution, supply/demand, market power).
 
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Mr Pig

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Jun 17, 2015
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The first significant point is that an earlier post stated that one fuel supplier exceeds the RON level whereas another only meets it (albeit this is for petrol) and it was assumed that the same is true for cetane equivalent in diesel. If both market the same cetane or RON levels, then they will both be required to achieve this; however, neither will give away the most expensive base product for free, as this comes straight off their bottom line.

But I think we've established that the difference in fuels is not the base product but the additive packs? When talking about diesel anyway.

The second significant point is that supermarkets sell almost half of the vehicle fuel sold in the UK, but from less than a fifth of the total number of fuel stations, which has a significant factor on the cost (distribution, supply/demand, market power).

OK, but I'm sure McDonald's will outsell your local independent restaurants but that doesn't mean the quality of their food is higher. People buy supermarket fuel because it's cheap. Because most people are short sighted and cheap. When I asked my local tyre fitters about good quality tyres I was told that hey'd have to order them in because most people just buy the cheapest tyres they can get so that's all they stock. All the arguments about supply and demand etc apply just as well to burgers and tyres as they do to fuel but that does not mean you get the same quality as a more costly product for a budget price.
 

mdaw1985

Active Member
Aug 3, 2008
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St.Leonards, East Sussex
Generally for me I will always go with branded fuel over supermarket with the exception being tesco momentum (petrol). That's whether it's from the big four Shell, BP, esso, texaco (maybe Total should be included to make 5) or other branded fuels like Jet, murco, Q8, gulf etc. Like it has been stated before I believe their additives better clean and lubricate. I don't think supermarket fuel is evil and will destroy your engine but I don't think your engine will be looked after quite as well.
I ran diesel for about 13 years until last year and primarily used v power diesel where possible until it became silly money and ran standard shell or esso mainly. I didnt notice a huge difference but I did feel it was best on v power over any other premium fuel like BP ultimate.
With my petrol however I have found that it runs smoothest on standard esso. The premium doesn't feel any better. It ran well on jet ultra (premium), v power is similar in feel. Tesco momentum is my go to but is a little rougher sounding but still good. Only petrol I've not liked so far is standard BP. Two tanks from different garages and the car has felt crap which shocked me.
 
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Mr Pig

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Jun 17, 2015
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Only petrol I've not liked so far is standard BP. Two tanks from different garages and the car has felt crap which shocked me.

Interesting you say that. I've not noticed any difference with the Leons but with other cars I noticed that other brands of fuel gave seemingly better results. Unfortunately the only local stations I have are BP and Morrisons. There is no Shell garage for miles.
 

KXL

KXL
Dec 15, 2016
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London, UK
Interesting you say that. I've not noticed any difference with the Leons but with other cars I noticed that other brands of fuel gave seemingly better results. Unfortunately the only local stations I have are BP and Morrisons. There is no Shell garage for miles.

Might be a TSI quirk, I had the same feeling, with my 1.0TSI Ibiza, but nobody mentioned this until now, so thought it was in my mind. However I found no discernable difference at all between Shell/Texaco/Esso/Jet 95 RON. Shell 99 RON gave best Mpg (doesnt work out cheaper though) and Esso 97 gave smoothest engine..99 Momentum nothing to note...Had same feeling with my current non-Seat car with a 1.5T engine.
 

Woody_72

Active Member
May 10, 2020
502
252
Northwest England
The UK's almost certainly different but in America all fuel from refineries goes into a national pipe network. This means there is no way of producers getting their own fuel back ie if Texaco put 100,000 barrels of gasoline into the network in Texas and wanted to take out 100,000 barrels in New Hampshire, they'd get 100,000 barrels of gasoline that could have been refined by anyone. The only difference when it is sold is the additive package chucked into the tank at the dispensing garage where it's purchased by the public.
 
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SuperV8

Active Member
May 30, 2019
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Doesn't matter in the older PD none DPF engines.
Modern CR DPF engines I have been reliably informed (by engineers who design diesel systems/pumps/injectors) that 'premium' diesel is better long term for the CR pumps & DPF's. As has been mentioned previously all use the same base stock - but the additives (which can be important) are better in the none-supermarket fuels.
CR pumps rely on diesel fuel for lubrication of the high pressure areas of the pump, where as PD unit injectors use engine oil at the high pressure points.
For what it's worth my car (184 FR ST) does slightly better MPG from Shell/BP etc vs supermarket fuel, which just about makes up for the difference in cost.
I also think it's smoother - but without me doing a double blind study that one is more subjective/ take with a pinch of salt.
 
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BillyCool

Active Member
Jan 16, 2020
706
275
Leicestershire, UK
For me, the whole fuel discussion/debate really depends what you want to get from it.

Personally, a performance fuel isn't going to make your car suddenly more powerful/quicker. It may run a bit better but I think that a lot of the benefits are more subtle.

My old Mk1 Leon TDi had done 220,000 miles when I finally got a new one. It had the rock solid PD engine and probably did the last 100,000 miles on BP Ultimate. It just seemed to like it. Ran well and never had any issues. Just before I sold it I checked the EGR valve and it was pretty clean. Can't say it was specifically the fuel but I've seen some really clagged up ones and do think that fuel choice kept the car healthy.

I think that a lot of the benefits are longer term and less obvious. As @SuperV8 says - it's more to do with lubrication and protection of the inner workings of the fuel system and engine.

If you have a company/fleet/PCP type car that goes back after 2 or 3 years with 50,000 miles on the clock, I don't think you'll be affected (or bothered) so much.

It's the people with higher mileage cars who pick up the bill for new parts and extra work. My Mk3 Leon had 60,000 miles on it and now it's on 103,000. I like to put Shell V-Power through it because it seems to like it. I intend to keep the car and would like that extra `protection`. This car also has a DPF and I hope that a decent fuel helps keep that healthy as well.

Due to lockdown and a lack a Shell garage locally, I've been using Tesco diesel. I have a fuel additive that is meant to be the same as the major fuel folk and I'm currently using that. Rather than an extra £10 per tank of V-Power, the additive costs about £1. My car has been chipped but is still giving me 55mpg on local runs and 68mpg on motorway runs. I'm not saying that's just the fuel or additive but I'd like to think that it helps.

Of course, the fuel companies are very secretive about what they add and how it all works. Some say it is snake oil and just a placebo product. I do believe they add value but it's very hard to measure.

For me - I think performance fuels help, but I think we're all different in how we measure that or view the perceived benefits.
 
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