Petrol - Supermarket vs. Branded

tomstickland

My personal opinion based on observations over the last 10 years is that branded fuel gives slightly more mpg than supermarket fuel. I found a link to a bike magazine test on another internet forum last night. They found a 2% increase in power between supermarket and branded fuel, not sure on the mpg difference. I'm going to keep records for the next few months and I'll look to see if there's any difference on supermarker vs branded.

Gorgeous_George

There is a difference.

I filled up at local garage and returned 50mpg travelling 359 miles to my parents. Filled up at ASDA ready for the return journey and only managed 41mpg.

I was driving a Honda Jazz with the tripmeter set to show mpg. Try as I might, I could not beat 41mpg on the return whereas the 50mpg was easy to achieve.

Its mainly to do with octane levels.



GG

Crabman

Octane levels?? I thought it was to do with how much additives the supermarkets add per unit of petrol??

JasonLVC

Have to add my view on this.

My cars definately records a higher MPG when I use Shell (ordinary, not optimax). My diesel car has a mpg/trip computer and I drive the same, short journey every day. When using Tesco, etc I get about 42mpg, with Shell I get nearer 49mpg. I also noticed this in my old job which invovled about 45k miles per year in various cars/vans - again, Shell was the best.

That's a big difference and I do think that it's all a big con. Yes, Supermarkets are 1-2p cheaper but if you go less miles on it then you need to fill more often, against more expensive fuel that lasts longer.

Conspiracy Theory time. All petrol is refined by the same company(s) and as earlier post states, it's the additives in the petrol that make the difference to performance/MPG, so of course the refiners will be happy to sell petrol to Asda for xp as they know they'll have to buy more if it anyway!.

I don;t know about where others live, but the Shells stations up here in Leicester are usually very cheap. One in Croft (Leics) is currently charging 94.5 for diesel which is actually cheaper than any of thge supermarkets (bar the 5p of per £50 spend offer). Might be worth checking out your local Shells!

JasonLVC

Maybe we should all fill our tanks with X brand and then drive until the warning light then fill up with Shell/BP and see if there is a difference.

I know there are posters here who don't believe the mileage difference but I've seen it for myself and experimented with different fuel providers and have concluded that Asda/Tesco are a false economy. Of course, if you factor in the tesco points or nectar points then fine.

tomstickland

For the last few weeks I've been seeing how much mpg I can obtain from my car by driving for economy. Using big name stuff I should manage over 200 miles before reaching the half way marker, and normally manage 370-390 miles on a 10 gallon tank. This week I've been using Asda petrol and I got to the half way point at 180 miles and things are going down a bit too quickly. I'll wait and see, but I don't think I'll manage 370 miles on 10 gallons.
I am going to keep records for a number of months and then we can look at the stats.

gazhawkins

Yes, the octane thing is a complete red herring. If your car is set up to run ordinary 95 octane unleaded (most are), then running it on super unleaded (98 octane) isn't going to make a great deal of difference (economy wise) - except you will have a bigger hole in your pocket.

If you run a Subaru Impreza, which is set up to run on Super Unleaded, then the difference will be in performance. Chances are, if you ran such a vehicle on 95 unleaded, it wouldn't run as well - leading to a drop in performance and economy. More info at:-


http://www.petrolprices.com/about-fuel.html

Gorgeous_George

Supermarkets do not produce petrol. They buy it as cheaply as possible regardless of quality. As a result, they often have a lower quality fuel than the more-informed petrol companies would wish to sell or indeed, need to sell.

I believe Shell, Esso and the like supply better quality fuels. However, that is only part of my reasons for not using super4market forecourts.

Cost is usually marginal at best. For every penny off a litre of fuel a typical motorist will save 20p per week. To save this, they are prepared to drive to the supermarket solely to fill up. Just one additional mile and any savings are wiped out - even before the quality of fuel is looked at.

Now, let's travel ahead 20 years. The decline in roadside filling stations means that we all need to fill up at supermarkets. To justify the trip, we shop there as well, Town centres are a thing of the past. Prices will not need to be competetive anymore.

(harry enfield voice) Is that what you want, 'cos that's what'll 'appen!



GG

taxiphil

A very interesting thread. I'd always assumed all fuels were the same but I'm starting to believe otherwise after reading this!

I do wonder, though, that if Shell/Esso/Total/BP fuel did contain superior additives to supermarket fuel, why they don't heavily advertise this fact as a selling point??? You would imagine, in an era when they're losing an ever-increasing massive share of the market to supermarkets, they'd be desperate to do anything to get customers back onto their forecourts. And surely the superiority of their product would be the perfect marketing point. So why aren't they making any song and dance about it?

tomstickland

an increase of a few degrees in outside temperature could easily account for an extra 9 mpg.

It wouldn't make that much difference! 30mpg to 39mpg is a 30% increase in mpg, and a few deg of air temp won't do that.

My view is that all of the anecdotal evidence suggests that people have seen an improvement in mpg with big name petrol and hence this suggests that if there is any difference, it's that big name stuff is better for mpg. The difference might well be smaller than the stories suggest. Going on my current test, I managed 37mpg on Shell and then I put in Asda petrol and I've driven even more carefully, but I'm down to warning light level at 320 miles. If I can do another 40 miles and then fill up with 45.4 litres then I'd agree that the difference is small. This is why I'm going to keep records. It will average out many factors over time and allow some sort of statistical evaluation.

Thinking back to my shoddy old 1.1 Escort, that was a very sensitive engine and I noticed that big name stuff made it run better than supermarket fuel. Makes sense to me.