23.0 MPG
 

Over the last 5000 miles our X has averaged 17.1 mpg with moderate in town driving and a couple of road trips.

I've been reading a bunch of articles on the web regarding adding Acetone to the gas and supposedly it increases mpg. I figured it was snake oil.

I decided to give it a chance. The ratio widely recommended on the web is somewhere between 1 and 3 ounces added to each 10 gallons of fuel.

I filled up today and added 5 ounces which puts me at the 2 ounces for each 10 gallons since our X's have an approximately 25 gal tank.

We took a 250 mile road trip which consisted of in town driving, mountain grades and normal freeway driving. I reset the trip#2 for the fill up.

I was so suprised to see that by the end of the trip we had gone from 17.1 avg mpg to 23.0 mpg.

Pretty incredible. I thought I'd pass along the info. You can do your own research and you can decided if its worth the risk. Of course I'm not a chemist or a BMW Mechanic so USE AT YOUR OWN RISK.

See attached pic of the result.

I got close to this on my road trip to westfest 1V by keeping it under 80mph. :thumbup:
No chemicals added.

its not the acetone that works. look at your average speed, its 57.2 mph. that happens when you reset the gas consumption report and drive at high speed, you always get higher gas mileage. but the longer the measurement you will drop down to somewhere 17.xx mpg. the average speed of everyday driving is about 25mph that includes city and highway. trust me, i tested this so many times already (no acetone, just the measurement). acetone will kill your engine for sure, do not try it again. i consistently gets 17 mpg on my X and 20 mpg on my 530 over a long period of measurement. AGAIN, do not try ACETONE, it only harms your engine.

You are probably right. But I reset the consumption #2 at fill up. I changed the avg speed when I was about 20 miles away from home thats why it said 57mph.

Before that the avg was around 30mph which had not been reset in the last 5000 miles.

I agree it's not the acetone: In our case we set the the gas consumption report at the beginning of the trip and indeed the miles we traveled VS the fuel in the vehicle equaled between 22 and 23 MPG. Of course i don't get that around town.

I'm glad to see that you guys are getting around 23mpg on longer trips. We have taken 2 other trips that were about 300 miles each -- all freeway. We have always gotten about 17-17.5 mpg. I figured that maybe the 4.4 just drank more fuel so I didn't worry about it.

I was suprised on this trip which included lots of passing in the mountains to get the 23mpg. Who knows.

I have gotten 22/23 on interstates when I held to the speed limit with a 4.4i 04 sport.

Yup, same here - but staying the speed limit rarely happens.
Anyway, I wouldn't go dumping nail polisher remover in the gas tank even if really does give a few more mpg.

Just watch your speed and right foot. Then you'll get decent mileage. I got that same 23.0mpg driving back from Raleigh averaging 86mph. No kidding! I was beating that gas pedal on I-85! :D

never reach 23mpg on interstate.... but I do get around 20 for driving 90