zlacker

So no petrol is permitted to be higher quality (for the same octane rating)?

ie you're asserting there is zero variance in quality?

OP wrote lower quality, not low quality

>>gib444+(OP)
By "lower quality" I did mean "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.

>>alexfo+hf1
Yeah fair enough that's probably true

Companies are permitted to add additives etc but whether that meaningfully improves quality I'm not sure