I just took my 2003 Cooper S in for a look over at Pacific Motorsports and he basically told me that because I was using "average" cheap'o gasoline that I couldn't expect to get more than 16 miles to the gallon.He said that the octane level has to be above 91 if I want to get better gas mileage than that.

I did manage to drive across town today and was actually able to pull it out of fourth and even once got it in to sixth on the way back. but the best I been able to get lately is 18.5. you guys think I need a tune up, or what?

thanks Mike Frye

 

A gen 1 s should get over 20 mpg easily when cruising, 30 mpg on the highway. You definitely should be running good 91 octane in a supercharged motor all the time. Thke it to a reputable MINI Mechanic. Hopefully it just needs a new air filter

 

Great advice CaptnAmerica, good luck Mike!

 

Yes, you will definitely want to run premium fuel in any supercharged/turbo vehicle. I typically have seen anywhere from 22mpg-30mpg for highway driving for an R53. When was the last time you did filters/plug replacements as well?

 

I get about 28mpg on the highway with my 2002 Cooper S. I guess not too bad.

 

I average about 31-32 highway, 25-28 around town in my 03 R53. I use Shell, Exxon and Mobil 93 octane on a constant rotation when I fill up. These three are listed as Top Tier gasoline according to this website, Retailers along with others. I used to use Chevron and Texaco, but they left our region. I check the tire pressures every other morning and I check the oil every fill up.

 

I drive my R53 pretty hard in town and I got 22 mpg.....I did a 280 mile trip and speeds were 85+ and some as high as 115.....got 24.5 MPG......coming back I turned cruze control on 75 mph and got 28.5 mpg.....saved 4 gallons going slower....2.50 galX4=$10.. not worth the fun of bookin down the hwy in a Mini, only good thing going 75 mile is you are not constantly looking for police and it is easier on the car.

 

What would happen to run 87 octane
in supercharge motor? I just bought the car and was talking to a friend with Viper and also a Lambo, as crazy as it sounds, he said he ran 87 octane in both and had bought both new years ago and no real issue and mpg is better with 87 octane?

Any comments?

 

If your owners manual and gas cap state to only run premium fuel then only run premium fuel. I've seen lower HP output, even knock (pinging) and a few other not so great things when individuals have run the incorrect octane.