The mileage on my 2003 MCS with 50,000 miles used to average 31 or so on both the electronic reading and hand calculated on my weekly commuting. I always fill up my tank until the handle clicks and never anything more. Now the car is only getting 28.0 MPG over several tanks and nothing has changed that I can think of including the speed I drive, the route traveled to work or the octane of the fuel.

The only things I can think of are the change to winter formulation locally (Connecticut) and I replaced both front and rear brakes a few weeks ago (maybe some dragging? They shouldn't be).

I know 3 mpg is not that big of a deal, but I guess seeing 280 miles and needing a fillup is somehow less fulfilling for owning such a small car than 310 miles per "tankful".
Thoughts?

 

3 MPG is about my delta to know its time for a air filiter cleaning and oil change @ 31 MPG a fillup arrives for me at 421.3 miles, I put in 13.2 which means in a pinch I could have squeezed 450 out of that fillup.

 

I Always get about 10% less mpg in the winter. I always attributed it to "winter blends".

This has been consistent with the MINI and my company cars for the last 5 years.

1 Explorer
1 Grand Prix
3 Taurus'

 

I also have an 03 and go through the same thing. Check your tyre pressure. This time of year I always notice a drop in fuel econ. About 2mpg is due to the change in pressure from ~34psi to 26. The other 1mpg is just from the colder weather. Sure the MINIs might run better in cold weather, but they are also running just a hair richer.

By the end of winter my econ is usually back to normal in that 31 range.

 

OH my gawd, I would give my left #^* for 31 mpg or 28mpg. My commute to work is about 4 miles long, and seems to have about 18,000 stop signs. When I drive like a grandfather, I eek out 18mpg. My hat is off to you for getting such great mileage.

Currently I am sitting @ 15.1mpg...

 

Tire pressure?

 

WTF? I have a MC and get 27...I try to keep it under 90 highway...I get 29 driving conservatively.

 

I noticed the same drop once winter gasses came around, although I don't know if that's the difference for sure. My MCS goes 60 miles a day on the highway, and I normally see 30-31mpg, but recently it went down to 26-27.

I put in a whole bottle of redline sl-1 (as a quick clean treatment) and all went back to normal, at around 30 or above.

mb

ps - just for craps and giggles - the best I've ever done in my MCS is 374 miles to a tank. Score!

 

fprintf just wondering what they put in your gas to winterise it. If they add ethyl alcahol this may be a factor in the low milage. Alcohol has less BTUs per given volume then gasoline. Up the alcohol content and presto, lower gas milage

 

you probably use the defrost mode in winter...

 

Thanks for the replies. Here in Connecticut it has not really been cold enough for me to think it was the cold weather (or defroster) affecting the mileage. I should check the tire pressures. I just might try a bottle of injector cleaner for giggles.

They *do* definitely put ethanol into the fuel here in the winter time as a replacement for that awful MTBE they used to use. I figured this was a partial cause, but if they use 10% ethanol I should not be looking at a 10% decrease in mileage.

I'll take a look at my air filter. Honestly I have no idea where it is, as embarrassing as that sounds... this is what you get when you resign all vehicle maintenance to the dealer while under warranty. It is time for me to start learning a little more about this vehicle, though it scares me silly that something major will go wrong and I'll have to let the Jr. technicians at BMW/MINI fix it (@$100 an hour)!

 

Do you have the auto temperature control? I found out the auto system uses AC, even in the winter. Unless you specifically turn off the "snowflake" button.

 

I do have auto temperature, but I rarely have the snowflake turned on.

 

It's a late reply, but I agree with camminich - tire pressure pressure is a very likely culprit.
Greg

 

Get with a fellow MINI owner in the area thats alittle more comfortable under the bonnet of a MINI, they can teach you a few things and you won't have to worry about the sillyness.

 

I agree, too....check the tire pressure weekly. I get better mileage once I get out of Cali.....we must have very doctored fuel!

 

I was reading this thread on mileage and noticed the remark about turning off the AC in the winter. Nice try but IF you use the defroster and the MINI is like most other cars, the AC runs anyway in the defrost mode.
The reason for this is to remove that annoying fog on the windshield. The AC removes the moisture causing the fog and then the air is heated to do its thing. I have to stop using the smilies!!!

 

They still call it fuel in CA, I thought that was hazardous to your health

I always check the tire pressures weekly, and a 10 degree change in air temp outside usually means I'm adjusting something too.

 

Assuming you have the auto A/C I'm A/C less 90% of the time compliments of the manual controls and choice, in fact I generally only run it to prevent damage tot he system or I'm sitting in traffic and its 100+ gerees out.