I think it's been determined that the push button sequence for resetting the DME doesn't really reset the "adaptations" in the DME....and that's what you really want to reset. In order to do that, you need some BMW software (ebay), and a laptop.

I've reset my adaptations several times........it's noticeable because as soon as you hit the key on the laptop to reset them, the car will idle kind of funny and then smooth out again. Not really sure I noticed a gain in HP or MPG after the reset though.

Quick update- filled up on Friday and got 16.6 pg. 11.6 gallons to 191 miles. Currently it's all short hops under 3 miles with a lot of ac but it'll soon be driven on highway more. Still happy

Even with just doing short trips.....you should be getting much better than 16mpg. That's almost as bad as my 7000lb Dodge Ram with a 350hp HEMI in it.

Do you have an aftermarket tune that's running super rich? Are your exhaust tips black and sooty?

No and no. Car has 59.5k and meticulously maintained. Did 21 the first time i recorded mpg and 18 for the next one then 15 and now 16

Often mis-sized tires can throw off the speedo and all calculations....
And wider rims/tires do hurt mpg...
The factory mpg numbers were with the stock 16 rims and 195/55r16 tires, a 6.5 inch rim....folks with the 17's that tended to be heavier never seemed to do as well...and variability here....the ratio's in the tranny changed with the refresh in 2005.....so when you read what folks got, you have to keep it all in mind....

You should be getting 22+mpg without even trying...even running it pretty hard around town. On the highway 25+ is easy, and should actually be more like 27mpg (I was getting a little more before I went with the wider tires). some people are even saying they are in the low 30s on the highway. 16mpg is horrible...definitely doesn't sound right.

If you're doing stop-and-go driving averaging less than 20 MPH your mileage will be below 20 MPG.

Yes, I guess that is possible. When I think "city" driving I think 35-45mph driving with a few stop lights every now and then. I guess if you never got out of 1st gear...i could see you getting under 20mpg....but 16mpg is still crazy bad for a mini.

Cruisimg speed in the city is around 30 (goes from 25-35) and it's generally in fourth gear. I'll seehow the mpg is when I start doing some more highway driving. If I don't hit 20, then I'll start worrying.

For San Francisco driving, that is on the low side but not particularly notable.

Quick update, put a little over a thousand miles on it. Car is now used on thr highway more, about 7 miles on way. The mpg went up to about 18 and stayed there for a few fill ups but it just dropped back to 16. Car doesn't feel sluggish and doesnt smoke. Put fuel system cleaner in at the last fill up to see if that helps. Any thoughts? I feel like this is now a problem that needs to be addressed.

I just filled up and I averaged 21 mpg. This is 7 miles of stoplight every half mile, and 30 miles of highway driving. I wind it out a little bit too. On the highway I hit the cruise at 74. I was actually surprised that it was that decent.

This sums it up, and what I see as well.

When Raven was stock with just -17% SCP, I easily saw 34 mpg highway if kept under 70 mph. Best Hwy now at same speed is 28mpg-29mpg. And that's with all the weight reductions I've done. Worst I've seen is 23 mpg with spirited driving.

Fairly modded 03 JCW, I average 30 freeway (70mph. I can hypermile it over 40 if I try,) 26 city, not pushing it.

Don't lug a boosted engine. flooring it at 1500-2000rpm will give you worse mileage than half throttle at 2500-3500,

I still say something is wrong if you are only able to squeeze 16mpg out of your mini. That's what most 400hp 6,000lb half ton trucks are getting.....actually, they get better than 16. You should be able to get low 20's without out even trying....high 20's if you are driving for good mpg.

Where do you recommend I begin? I agree it's outrageous. I bought this over a wrangler because I was hoping for atleast 20 to make it worth it.

Have you checked that the brakes are not dragging, tire pressures are correct?

I'd almost think you may want to check fuel pressure and make sure there are no fuel leaks.

How's the spark plugs? Coil pack okay? Cam and crank sensors usually are fine until they are not and usually throw a CEL if they are misbehaving.

Coolant temps? Engine running cool? You can use the hidden codes to track coolant temps. Motor will run rich (longer) if thermostat is stuck open. Takes motor longer to get up to operating temp.

OBD - Hidden Menu thread:
https://www.northamericanmotoring.co...-obc-menu.html

Your R53 is clearly not running right if the mpgs are that low! My son's car now has about 218K miles and is averaging 25-26 mpg on his commute back and forth to school. (Nor Cal, highway 280)

Like Zsm said....start with the basics. Tire pressure, brakes dragging?, plugs and wires in good shape? Air filter clean? Any codes?

Are you running a different sized wheel that could be throwing your odometer way off?

How many miles are you getting from a tank of fuel? I can get 300 pretty easy...and still have a little fuel left.

City driving is a big variable. In my city it means lots of stop and go, sitting, trains, lights and almost no straight runs. I get able 18-19 mpg. On the highway with a light foot I have achieved 34mpg. I never use the a/c so it could be worse, on the other hand a auto vert is much worse than a manual coupe for FE.
If you have lots of hills, stop lights, stop signs, short trips, use a/c, and are heavy footed then 16mpg is possible without anything being wrong with the car.
Doesn't hurt to make sure the car is in good condition. I would start with new plugs and wires. Clean air filter, synthetic oil, clean fuel injectors with Techron.
A failing O2 sensor can cause bad gas mileage without throwing a code, but they cost more than the other stuff, so I would only do it if things don't improve and it was original.
Pump up your tires to 40 psi.

I've noticed my R53s CPU's numbers are different than the numbers my OBD system produces. The OBD actually reads lower numbers than the CPU. Just a thought... Maybe check it with a OBD app?

Also... Who has the link to the coolant flush, shop vac way?

Normally yes, but not sure that is correct in this case.

If you check the gearing on our cars, you will find the auto is about 20% taller in top gear. So on the highway you are turning significantly less rpms at a given speed. Hence you should be using less fuel, making the auto more fuel efficient than the manual.

Regards,
Jerry

No obd cpu. All by hand calculations (miles on tank/gallons filled) Always brimmed.
It's a stick so it should be better than an auto.
I do try and drive smart.
Will double check service records to see if anything mentioned was done by previous owner. Only has 60k on it.

That's pretty ridiculous. I get 24 mpg when I short shift and never accelerate more than 1/4 throttle. And I get 28 100% highway.

Please get your revs up. Approximate rule of thumb: driving in the 20-29 mph range=2nd gear. Driving 30-39 mph=3rd gear. Driving 40-49 mph=4th gear. etc., etc. If you don't, in all probability, your repair bills will far exceed your expenditure for gasoline. BTW, I only get around 10 mpg while on track...but who cares?

That's what I do. I shift between 2-3000 (depending if I can speed wise) Around the city on city streets, I'm in3/4 around 30 mph. The only reason for that is the speed limot is 25 in the city and I stick around 30. As a result, I upshoft because the revs would be around 2500 and I keep them around 2000. (Forgot the word to describe this. I know what it is in Polish when my dad tells me)