>> 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

- "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."