I just got an email from Consumer Reports magazine, suggesting that cars whose makers only recommend rather than require premium fuel did just as well on regular fuel in their recent tests on a 2015 Acura TLX 4 cylinder and a 2016 Nissan Maxima V6. The manual for a 2025 F66 suggests AKI 91 fuel is recommended, and AKI 87 is minimum. Consumer Reports claims they got the same mileage and performance out of regular fuel as out of premium fuel, with no audible pinging or knocking. The potential savings are currently 83 cents a gallon, less any cost for increased maintenance needed as a result of using regular fuel.

Has anyone here tried a MINI Cooper S on regular fuel? If so, how did it perform, and were there any resulting problems?

I'm only spending about $20 a week on fuel myself, so don't expect to switch for any potential savings, but am interested in whether I need to worry if anyone accidentally fills my MINI with regular fuel?

 

I save about 80 cent per gallon by filling up at Costco with premium.

 

I always run premium daily. I worry that the Injectors or HPFPs will not like the lesser grade also i sign up for gas programs here and get premium for near the same price as regular with all the kick backs.


https://www.northamericanmotoring.co...gh-octane.html

 

Penny wise, dollar foolish. I don't take car advice from Consumer Reports anymore.

 

You’re in the F57 forum, so I assume you’re asking about a 3rd gen car and not a 4th gen car (you mentioned the F66). MINI recommends 91 and requires at least 89 for Cooper and Cooper S models, and recommends 93 and requires at least 91 for JCW models. Why go against manufacturer recommendations to save literally a few bucks? Also, CR did one test in one situation. What about long-term effects or experiences? No thanks. Also, MINI recommends Top Tier gas, which is irrespective of octane rating.