Originally Posted by skalberti
Ok here's some real world data on a 35i with 7900 miles on it. Drove 167 miles averaging speed between 80-90 mph. I filled up prior to leaving and then filled up at my destination. I used 7.6 gallons 89 octane. Do the math it's 21.9 mpg. The computer said 21.7. I think it gets 1-2 mpg better with 93 oct but BMW says use 89 oct on the gas tank door. Diesel where I live is $3.99/gal where 89 oct is $3.14/gal. So in my area it's just not worth it for the diesel. Also the air temp was between 58-62 degrees.
I hope you mean it's not worth it for the PREMIUM as I highly doubt you are putting Diesel in the 35i, right? Also, 80 to 90 MPH is WAY faster than 95% of the people would drive so although you may feel that is a "real world" scenario, I doubt ANYONE else would agree. Try again driving 65MPH and let us know the difference. Also, those running Diesel have reported 29MPG even running 80 so the HUGE 33% difference between 21.7 & 29 would warrant driving the Diesel if there was an option.
I did a search on gas buddy in your area and while there are stations charging $3.99, it looks like there are also a number charging $3.72. However, over .50/gallon would probably be even to have even me running regular.