Placebo effect! Stop doing that and you will see no difference at all. I was doing 40k+ a year for good 5 years for company and only supermarket diesel was used. The car was Toyota Avensis 2010 Reg. So it done well over 250k in 5 years and engine was as new on supermarket diesel- not a single problem because of fuel.
Call me a fool but I do a lot of miles for my company & therefore a reliable vehicle is an upmost both for myself & the company & therefore to ensure a clean maintenance free engine as possible (besides regular service intervals) I fill up approx once or twice every 2 weeks (depending on miles driven) to help the engine run as smooth & responsive as possible. And yes I do notice the difference.
No I don't! As there is no difference at all. I cant believe so many people believe these marketing tricks. Have used only supermarket fuels(diesel and petrol) in past 18 years and never ever had a problem because of that. And never used any additives, like Redex or similar. I had a job measuring lubricity and anti foam additives for Shell research I wasn't pretending. It's all farmed out to companies like Infineum and yes the supermarkets put the same stuff in now as the brand's as all the research is done. It's all the same stuff.
You dont see difference between regular and „premium” fuel ?
Is there any fool, who buys Premium fuel?