I have 75k miles on my 02 MCS. So far my OBC said 29 MPG but on actual manual calculation is around 26MPG. The best MPG ever was 29 and worse 23MPG.

 

I've been informed that on the first 100-ish miles on this tank of gas, we just hit 40.6mpg (according to the computer)

 

Ok, just picked my car up 5 days ago and already have about 200 miles on the car. Its a cooper S. Now I must be the absolute worst manual driver in the world or something is amiss because so far (about half a tank gone) it says my average mileage on the OBC is 23.8 mpg. I've done mostly city driving in chicago but have had two 35 mile trips on the highway too. Have the computer set to instant mileage and been watching to try to keep it up there. So what gives?

 

City driving will kill your mpg. Every time you hit the brake you are effectively wasting the fuel you used to get up to that speed. That said I should think you will see an improvement on the next tank as things loosen up. Then the break in period ends and you will accelerate harder ruining you mpg again!

 

Especially during the early part of your break-in, it would wise to avoid driving for fuel economy.
"Vary your speed" is most often mentioned and that will waste fuel.

Break-in requirement for aircraft prohibits any use of economical power settings
for the first 50 hours to ensure proper Ring/Cylinder seating.

A compression (cylinder leakage) test that is failed due to improper ring 'seating' after cylinder walls have 'glazed'
can only be resolved by New Rings and re-hone of Cylinder walls.

There is no need to violate any of your recommended break-in limitations,
but frequent acceleration with *higher* throttle in *higher* gears, immediately followed by deceleration
would accomplish this goal best, but that's not good for mpg's.

Gentle acceleration until normal temperatures (AVOID HIGH TEMPS!)
and then *something like ¾ throttle from 3,000 to 4,000 RPM* in a higher gear than you would *normally want to use*
and then back-off to insure avoiding 'hot-spots'; 'Lugging' by constantly using higher than normal gearing
(like going up that hill in fifth) should be avoided.

There are several links on this board to "Break-in Secrets" but don't take that to mean 'drive-it-like-it's-stolen' is necessary
or wise for break-in.

He does say "...Run it Hard...", but below that he goes into detail about what he means by that.

 

Cool, well at least that explains a little of it. Thanks. I have been driving it a bit harder than the recommended but nothing too over the top. And I have certainly been using the full range of gears and speeds. So I guess I'll just keep doing that and ignore the economy till after about a 1000 miles or so.
Thanks for the input.

 

Actually, hang on. I've been driving so far as I basically normally drive, in fact trying to be a bit more conservative. So in thinking about it, my original question stands... am I the worst manual driver ever? or will the economy of the car improve a bit once it gets broken in? Take my driving style out of the equation.

 

We have been driving as normal but changing up at or before 4500rpm. 75% of the miles have been on the highway hence the 40mpg.

Jolyrogr: You say it's mainly city driving - I imagine lots of start-stop traffic, traffic lights etc. If so then I think the mpg you are getting in a new car is on the money.

 

Interesting article Pilotart - but I think I would have done over 1200 miles by the time I finish reading it! ...and no offence, this is just someones opinion on a webpage (however qualified he may be). I think just being sensible is the key here.

 

Ok. I'm sure you're right. I was just reading so many posts of people getting up close to 40 mpg, I was expecting to get high 20's or low 30's average myself. But yes, much city traffic in Chicago. Stop signs, lights, tons of stop and go. The average was down to about 21 mpg and a highway trip (35 miles one way in rush hour traffic, but 35 miles back at night with no traffic, high speeds, no stop and go) brought it back up to 23.6 where it is now.

I'm coming from a Land Rover Discovery which gets 9 mpg so I was just over expecting a miraculous contrast to that. LOL. Thanks for the input.

 

I'm contemplating picking up a base Clubman for the gas mileage. At speed, say +75 mph, given its longer profile, do you guys think there would be less drag than a Cooper, ergo, a noticeable difference in mileage, or negligible?

 

You're reaching I think. Also a heavier car. negates any gains.

 

Yes, it's a given it's a heavier car, but the EPA ratings are the same - go figure. We already have an MCS, and looking to add the Clubman to the stable....I'm just trying to justify it to my wife that despite being a heavier car than the standard Cooper, it at least gets the same mileage.