Hey all,

I've finished tallying up some mileage statistics on the first 10,000 miles I've put on Winston. Since one of the more popular questions I get asked about my MINI is what kind of mileage I get, I figured I'd share the info here.

The official ratings for mileage on the Cooper base model are 28 mpg city/37 mpg highway. I drive a mix of city and highway (which I imagine most people do) and my average after about 30 tanks of gas is a little over 30 mpg. My highest on a tank of gas is 32.6 mpg, and my lowest rating on a tank is 27.0 (the car was new still and not quite broken-in - plus I was probably a little "spirited" that week).

The average speed calculated by the on-board computer over these many tanks of gas is 35.9 mph. The highest average speed for one tank of gas was 46.4 mph (yielding 30.3 mpg) and the lowest was 31.3 mph (yielding 29.2 mpg). As far as I can tell, there is not necessarily a correlation between average speed and gas mileage, which I found odd. I would think that the faster I drove, the worse the gas mileage would be, but the data doesn't support that. It more likely reflects the amount of time I had to spend in traffic versus cruising time. That "stop-n-go" stuff kills my mileage ratings.

The "Miles Remaining" figure provided by the on-board computer has an OK accuracy. Sometimes it's as much as 20% off from what I calculate based on actual gas usage and miles traveled. It's always off on the conservative side though (which is good) so it should do it's job and keep me from running out of gas. I've had it as low as "0" miles remaining, after which it seems to know that can't be right so it recalculates.

The closest I've come to empty on the 13.2 gallon tank is refilling with .6 gallons left (I put in 12.. The onboard computer estimated I had about 9 miles left on the remaining gas, my calculations based on my burn rate had me closer to 12 miles remaining before I had to start walking.

The most number of miles I drove on one tank of gas was 385.6, with my average being 354.5. Based upon the actual mpg calculations of each tank of gas, the most number of miles I would have ever been able to squeeze out of 13.2 gallons is 423.0. I have not yet had a pure, 100% highway tank of gas. I would estimate if I did, 450 miles shouldn't be a problem, maybe even 475 if I get some help from the wind. The theoretical maximum based on EPA ratings would be 488 (37 mpg x 13.2 gal.).

The octane of the gas I put in was never less than 93 so I can't really speak to gas quality and its effect on mileage.

Cheers,
Bill

 

Great report.

My mileage experience for 11,000 miles is about the same as yours. I drive on the freeway only about 10% of the time with the bulk being on country roads. I am at 30.2 average over all tanks

Highest is 35.04 and lowest is 26.48 (track day). My mileage has been a bit lower since the software upgrade.

Andy

 

I have had the OBC once calculate 300 miles left on my tank with 200 miles on it already. It ended up being 350 out of that tank with 2.5 gallons left I'm not really sure what happened.

 

I remember the days when we figured out MPG with a pen & paper -well maybe sometimes on a spirted drive

 

great report Bill
Did you happen to notice any correlation between seasons and fuel mileage i.e. less economy in wintertime?

Cheers,
Ryan

 

I remember paper

Here's my 02/02 build MINI Cooper 5-speed mileage.

 

Trippy that is a fantastic graph-all you need to add is the price you paid for fuel

 

>>Did you happen to notice any correlation between seasons and fuel mileage i.e. less
stop/go driving >>economy in wintertime?

Hey Ryan! Good to hear from you again! I actually began working at a different client right before the weather started getting colder so I can compare "windows down" weather and cold weather driving. The new client is 22 miles from my house on back country roads. I would estimate a full 1.5-2.0 MPG lower in the cold weather for the same trip.

Haven't had a lot of ice/snow yet which because of stop/go driving would drive it down even further.

Cheers,
Bill

 

>>As far as I can tell, there is not necessarily a correlation between average speed and gas mileage, which I found odd. I would think that the faster I drove, the worse the gas mileage would be, but the data doesn't support that. It more likely reflects the amount of time I had to spend in traffic versus cruising time. That "stop-n-go" stuff kills my mileage ratings.

This is correct. The stop and go's kill the mileage numbers; that is why cars have two ratings--city and highway with highway (faster speed) getting better gas mileage than city (slower speed).

But if your driving was all on highway, and you were comparing a tank at 55 mph with a tank at 70 mph, you'd find the opposite effect: higher mileage ratings at the slower speed.