sorry, long post. Summary:
My Cooper S is getting 17mpg City / 22mpg Highway
only upgrades on it areJCW Filter and Sport Suspension
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Ive had my 2005 Mini Cooper S )Manual Transmission) since October of '05. it has 4700 miles on it and for as long as ive had it it has been getting an average of 17mpg. i drive though the city mostly, but when i get on the highway its usually from 2-3 hours constant.

The only performance upgrades are the JCW filter and Sport suspension. At first i thought it was the engine breaking in, or the Filter but later finding out from friends that niether of those should lower the Gas mileage THAT much.

Parents said it must have been my driving. ill admit i have a slight "lead foot" but i just love this Cooper. Ive spent a full tank of gas driving as close to my "grandmothers style" as possible (easy on the peddles, slow acceleration, speed limit, etc.) that has been my best, getting 18.2mpg.

after hours on the highway im getting 22.3mpg.

I started looking through the different online forums and im seeing posts of people being discouraged because theirs is only getting around 22mpg

a friend mentioned it might be the computer incorrectly calibrated?

If anyone has suggestions of anything i can do from home id be VERY grateful. The closest dealership is 200miles from my home and id like to atleast do everything I can before driving it down there to be serviced.

thankyou
-Kris

 

My first question is how are you computing your gas mileage? The best way (if you do not already know) is to use your trip odometer to measure the number of miles you drive on a tank of gas. Reset to zero when you fill up, note how many miles you have driven on that tank when you next fill up. Divide the number of miles by the number of gallons of gas you put in. 350 miles divided by 13 gallons equals 26.9 miles to the gallon.

If you are rely on the on-board computer, then you must reset the computer every time you get gas to accurately record the mileage.

And yes, if your foot is in the throttle all the time due to your drivng style, then your mileage will be very poor.

I hope this helps! Good luck!

 

In calculating my gas mileage I always do it by hand as the OBC in my car is overly optimistic.

My MPG has ranged from a low of 17 (averaging 15 MPH on the streets of SF) to over 30 (on highway driving to Oregon and SoCal).

 

My OBC is a little optimistic compared to my calculations. I have a '05 with 7,3XX miles on the clock.

About a month and a half ago, my OBC read 19mpg, all city driving. I was driving pretty conservatively.

So I'm guessing your 17mpg is not too far from the norm.

 

bluegarvis is on track here.

calc you milage from fill to fill.
at first fill, note odometer reading.
at next fill, note new odometer reading and number of gallons for re-fill.
(miles driven)/(gallons used) = mpg.

everyone seems to agree that computer just isn't accurate

to improve?
the faster you change velocity, the more energy you waste.

slow acceleration, more efficient.
use your brakes - means you already used too much gas.

car is MOST efficient at about 38mph with windows up, no a/c, cruise control on, accurate tire pressure. (appx peak of efficiency curve for typical car)

faster or slower than 38, your efficiency decreases.

efficiency change between 55mph and 68mph is shocking. that's actually why ronald regan's administration made it the "national speed limit." saving lives is a bonus.

reference book is probably out of print, but look for Dr. Ron Wiers' "Chilton's Guide to Better Gas Milage." or something similar to that title. I used to live next door to him. Guy tweaked a Rabbit Diesel to get ~70mph in competition. Made grandma look like Andretti.

--tm

 

I'm sure you're not the only one out there with low gas mileage. I start hard, drive, ahem, quickly, and brake hard. I'm really lucky if I get 22 mpg, and I'm calculating by hand, not by computer.

I know that it's my driving style that accounts for my average mileage. When I went through that break-in period, I kept my revs low and drove very (incredibly) conservatively. Kind of like my mom. Even then, I only got about 25 mpg. I honestly don't know how some people get 30 mpg or so.

Oh yeah, I drive MCSC. I know I didn't buy this car for the gas mileage factor, but for the fun factor. I just weighed that factor along with my other expenditures. I honestly don't do Starbucks as much as others do, so I figure I break about even with everyone else!

 

Low gas mileage? If you make short trips with lots of stop signs and hills like I do you will get 17mpg in the city. Not a pretty sight.

 

I only drive in the city, never really hit the highway much. I don't drive like a maniac, but I get into it for sure, and I regularly see about 27 MPG in city with my S. I would be really worried if I was getting 17, personally.

 

For the OP I would be. For me, it's normal. S.F. is very bad for mpg. I do get close to 30 on the freeway.

 

its been 100 freaking degrees for the passed week here in NJ.... I drive mostly on local roads, lots of stops and starts and pretty hilly. I also drive in a way that would probably lead to poor gas mileage. I usually get around 23 or 24 mpg but after filling up this evening i calculated that i got about 18.5 mpg on this last tank. I've had the A/C CRANKED all week... i imagine that is probably the reason why. Did I mention its been 100 freaking degrees all week?!?!?!?!?!

 

My OBC has been reporting 23.5 this week - about 50/50 city and highway. Temps came way down today here in Chicago. I took the opportunity to turn off the a/c and open up all the windows on my way home tonight No change in my OBC milage

 

How did you come up with 38 MPH? Just curious.

 

30.2 for my 06 MCS SB/S Checkmate with 2,1XX on it

 

Okay, I just filled up last night and I calculated 20.5 mpg.

This might be stupid, but does the state you live in account for your mileage as well? I was talking to a guy in a Honda Pilot, and he said he got 28 mpg in his thing. Well, I never got anything above 18 mp when I had mine, and my husband mentioned he had Oregon plates. I took it to mean that in CA we have tighter smog restrictions than OR, and as a result our averages are lower?

Anyone with an opinion?

 

We have that goofy gas in CA but I don't know if the rest of the country receives the same.

The MCS runs rich by design. Maybe, yours runs even richer? I think if it is a concern, you should drop by the dealer and express this. At least, it will be on record for future reference.

 

have you tried maintaining your revs to under 3000 rpms?

 

It's not a "high milage" car, it's a sports car. )

I do most of my driving city miles, an occasional hwy trip. I usually get around 23-24..calculating by hand.

I also have a smaller rolling diameter tire and speedo is off, giving me more than actual miles.... so likely even less mpg. Foot weight varies.

Get a hybrid if you want high milage. :-)

Your #s sound a bit low. How is it running?

 

Just wanted to put in my experience in here for reference...I am under 3k the majority of the time.

 

I just started getting better gas mileage on my last tank. I wonder if they ran the oxygenated 'winter gas' longer than normal in Cali this year? I doubt the Denso plugs I just put in would account for a 2MPG increase in fuel economy (was getting 27.2 and now getting 29.7 per the OBC)

 

Also make sure you're using good preimum gas. It will run with the rockgut but it will not get it's best mileage and slow down. I drive a MC instead of an MCS because I knew I'd enjoy it way too much. It's probalbly the perfect automobile. Please post what you get. I get 414miles per 13 gall tank or about 31 mi/gal consistently.

 

New MCS with 200 miles on it. Reset the computer MPG three days ago and have averaged about 29 since then. City driving including short sections of Hwy 25 & 40. I shoot for 1800-3000 rpm, and keep the A/C off in the mornings.

 

I upgraded my 03 MCS when I purchased it at the dealer to a JCW package in 2004. This year I upgraded the JCW kit to 06 standard using the upgrade kit. I have since gotten an increase of approx. 80 - 100 km more per tank. I suspect the new flash made the majority of the difference.