Supermarket petrol?

[AWiseWomanOnceSaidFuckThisShit]

Someone said on here years ago they never buy supermarket petrol... only ever Shell / Texaco etc. For some unknown reason I've stuck to it religiously ever since! Does anyone else do this? Do you believe certain petrol is a better quality?

I've always driven old nondescript cars very happily on tesco's and sainsbury's petrol.

For a while I did a weekly commute of about 200 miles each way. I'd always fill up at the big Asda on the way, 550 mile tank so it worked out just right.

Once in a while the long motorway journey would use less fuel - I'd get back home after 200 + 100 local driving + 200 miles and still have 130 miles in the tank rather than the usual 50. I've no idea why, but different grade fuel would do it. The car doesn't have an eco mode or anything, and I always set the auto speed thing to 70mph.

I'm sure the supermarkets just buy from whoever's cheapest in any given purchase period, so the source of the fuel in the tanks there will vary.

I heard that it's usually the same tankers anyway.

My car wants high-octane fuel, it says so in the vehicle handbook and on a label inside the filler flap. I normally get the Tesco Momentum which has the octane level and is way cheaper than the branded ones, though a little more than Tesco standard fuel. I've filled with standard fuel when that was all I could get and the engine seemed OK with it but I don't want to make a habit out of that.

I have been driving for over 30 years and never heard of supermarket petrol. Why would it be inferior just because the sign said Asda, tesco etc.? My mind is surely boggled.

Our mechanic friend told us that supermarket petrol is not good quality. The only exception being the Tesco ones which have Esso fuel.

It can be a false economy to buy supermarket petrol thinking it’s cheaper, it maybe on the pump but if your mpg is lower then you’ll end up paying more. Shell etc maybe a higher price on the pump but you’ll get more mpg making it cheaper

If you genuinely think the mpg/quality is different, can you explain why? In terms of chemistry and engine physics?

Years ago it used to be that supermarket fuel was padded out with ethanol to give the same headline octane number (but with a different mix of content). Also shell etc had their own special recipe of detergents and good for your engine stuff in it. Supermarkets just got the cheapest on wholesale that day so pot luck on the source and ingredients although baseline octane rating was obviously consistent to the minimum standard.

Also fresh fuel is better than old fuel (not sure I can recall why!) so conversely, high turnover supermarkets might have fresher fuel than a little used premium brand station so even if it’s theoretically less good (more ethanol less detergent/whatever) if it’s noticeably fresher it still might be better.

I used to use performance fuel when I had nice cars. Now I have kids and a small engine with a turbo car (as they pretty much all are these days) which doesn’t care so supermarket all the way.

@BobbinThreadbare123 Because over the years I’ve filled up my tank to the gunnels and kept notes if milage and type of roads. Used to drive a duel fuel so would do same trip on both over a period of time and used different outlets for petrol.

I do drive to gain good mpg and usually manage 2 months on a full tank 40 litres & do a regular 20 mile commute at present

Lolz this is redic. Imagine having the head space to think about this. But somone probably dose!

As an aside if you drive 14000 miles per year and save 1 mile per litre it’ll save you £240 per year in fuel

It all comes from the same refineries, but the additive packages differ. Basic supermarket fuel will have none, branded fuel will have one package, the Vmax, super fuels etc another, which is where the price differential comes from.

I do know this for a fact as I work in the petrol retail industry, not with shell but their vmax is rated by far the best in the industry.

I only ever use the super products, and believe it’s better for my car, but supermarket fuel won’t damage it, it just might not be as good!

A friend works for one of the big oil companies. She’s always said that the additives in branded fuel make it a better fuel, but that all fuel is made to a basic minimum requirement. I tend to buy shell, she often uses supermarket fuel. One of my old cars used to do about 20% more miles per tank with shell vs Tesco fuel so it can make a difference I believe.

A few years ago, DH told me always to fill up at Tesco rather than the local (non name) fuel station. This was a rural area. One day, in a hurry, I didn't have time to drive into town to Tesco, so I used the rural station. The car felt sluggish. Afterwards, DH said it was the old fuel tanks they had. I don't think I would have believed him without feeling the difference. So I can believe in the hierarchy of fuel.

It costs 7p a litre more at the local shell where we live now rather than Sainsbury's or Asda. So £3.50 a tank. Big difference though.. they always have diesal, the Shell garage runs out. So I plan around Sainsbury's call ins.

My driving instructor told me to always fill up in the same petrol station.

When I was a kid, around forty years ago, my grandfather worked for Shell and father worked for Mobil. Father always used Shell petrol. It was supposed to be a lot better.

I've been going to the same Tesco station since I got my car eighteen months ago, except for once when I went to Morrisons and the car was definitely sluggish afterwards. DH uses a different Morrisons without any issues. I have a feeling that sometimes a particular petrol station may be less good because of how they maintain their tanks.

Watching this with interest.

Old fuel is definitely an issue that’s why you should empty your lawn mower out of petrol at the end of the season.
The additives in branded fuel do make a difference. One car I used to have needed good quality fuel and I could only get supermarket fuel so it had to have plenty of redex.

The main component - petrol - all comes from the same refineries, but the different companies put different additives in.