I know someone who avoids their local petrol station that is 10p/litre cheaper than most others nearby (within a mile or so) as they think the cheaper fuel must be lower quality. There are weird status things going on with purchases like this.
Only the other day my father refused to buy some branded paracetamol because it was ~5 times more expensive than the local pharmacy brand that was out of stock. (£2.25 vs £0.49 for 16 500mg tablets.) I'd usually agree with him but he was out of paracetamol and has been advised by his doctor to take 2x500mg a day and there was no viable nearby alternative.
A digression but for that generation (those born in 1940s/50s) that grew up with rationing I think it is hardwired into their brain to try and minimise the cost of so many things, but with lots of random exceptions. Later on that day he ordered an extra drink but decided he was too full once it had arrived so he left it. So he was worried about spending an extra £1.76 on paracetamol but not about spending £7 on a pint he didn't drink.
Many people decide what petrol station to use based on simply how close it is, what kind of shop is attached to it (and the bits of British snobbery around that), whether it also sells whatever else they want (bread, milk, beer, etc), or even whether it is easy to drive in and out of.
- "Top Tier gas contains higher detergent levels to prevent engine carbon"
- "Major brands use specific additives that enhance performance, while "no-name" or discount stations might only meet the minimum EPA-required detergent levels"
- "The condition of a station's underground storage tanks affects quality"
- "For the best engine performance and longevity, choosing Top Tier-certified gasoline is generally recommended."
ie you're asserting there is zero variance in quality?
OP wrote lower quality, not low quality
It's the reverse of "this one is more expensive therefore it must be better" without any evidence at all that it is the case.
Companies are permitted to add additives etc but whether that meaningfully improves quality I'm not sure