I'd at least go mid-range on the octane rating and stick with a top tier fuel such as Shell or Exxon. Avoid additives in my opinion as they can contribute to shorter sensor and catalyst life. My original O2 sensors lasted 260,000 miles, the second set went 106,000 miles but my driving shifted towards more city driving.


I stick with Shell premium and don't use any additives. My spark plugs always last more than 100,000 miles and I am still on the original cats.


2002 X5 3.0 368,600 miles
2014 428i 65,500 miles


2004 325i sold at 123,600 miles
2001 325i sold at 66,000


1970 Firebird under restoration