how to improve mpg

i get 15 if i drive my car like it should be driven...i can get 30 if i chose too..but whats the fun in that?

point taken about the more flow = more fuel... not sure why that didn't register

Originally Posted by ac_2007

Disconnect battery, I explained why in my previous post..

SOME WEIRD THING HAPPEN ON THIS WEEKEND....

I FILL UP THE WHOLE TANK WITH A BOTTLE OF INJECTOR CLEANER WHICH I BOUGHT FROM COSTCO AND HAD SMALL RIDE TO LONG BEACH AND BACK ABOUT 100 MILES IN DISTANCE. I HAD AN ERROR CODE PO0365 WHICH SHOW ME EXHAUST CAMSHAFT POSITION SENSOR WAS NOT WORKING PROPERLY. THIS CODE HAS BEEN ON AND OFF FOR MONTHS (MOSTLY ON). UNTILL I FINALLY PURCHASE THIS PART AND HAD ARRIVED ON SUNDAY.

ANYWAY, I DECODED BEFORE THE RIDE AND NOTICED THE CHECK LIGHT HAS NOT BEEN ON FOR THE ENTIRE TRIP AND ON BOARD COMPUTER SHOWS ME 26 MPG INSTEAD OF 18 WHICH I HAD BEFORE...... OF COURSE , MY RIDE IS ABOUT 90 % FREEWAY AT 70 MPH.

DO I STILL NEED TO REPLACE THE SENSOR..??

DOES THE INJECTOR CLEANER REALLY HELPED HERE...???

I ALSO BOUGHT ACTRON CP9575 AND I WILL RUN THE ENGINE BEFORE ANY CHANGES.

Originally Posted by the_curry_man

i get 15 if i drive my car like it should be driven...i can get 30 if i chose too..but whats the fun in that?

Lol I feel you. I get like 19 when I drive like I like to, but I can get 27 if I want to.

if your worried about MPG ride the bus or buy a bike

Originally Posted by ANREC330

if your worried about MPG ride the bus or buy a bike

Tire preassure
Clean air filter
Spark plugs
Loose un-necessary weight
Glide when you can

If you want to go to the extreme, accelerate down hills and coast up them, that will make your mpgs go way up. A is if you live in an area with lots of hills

You can incorporate a water vapor fogger into your intake after the MAF. The vapor will cool combustion resulting in more hp and mpg as the outcome. Similar to water injection.

Fresh state of tune, Proper tire inflation (OEM size tires) and a light foot will yield best mileage. Those wide 19's hurt your mileage more than just about anything you can bolt onto your car.

If you are at 50 MPH you should be able to comfortably glide 3/4 mile to stop. My car rolls forever. The hardest is on the interstate where traffic is bad... ppl cut you off so they can slam on their brakes. I swear the invent of the automatic transmission is an MPG killer. Those idiots stomp the gas and then stomp the brakes.

BTW - steady at 26.2... never installed the K&N. Laziness has become me.

Originally Posted by xavi330i

You can incorporate a water vapor fogger into your intake after the MAF. The vapor will cool combustion resulting in more hp and mpg as the outcome. Similar to water injection.

LOLWUT?

Seriously, though, with gas prices as they are, I've been running 100% water in the tank, and my gas mileage has improved incredibly. My mileage is now off the charts. I burn absolutely no gas now at all and the savings are huge. Only issue is I have to figure out how to get the water to ignite. I'm working on cold fusion, but think it'll be a bit until I figure it out; but when I do...wow!

Xaxi, did you do this in your car?

I know we can run in humidity, of course, but this seems incredibly odd to me...and yes, I made up the stuff above!

I've read a little about water injection, and people do report some small gains in MPG... something about adding more water to the engine makes me cringe though, especially with all the electronics in our throttle body/intake manifold.

The concept behind "water injection" is to actually spray a mixture of water-methanol into the intake manifold where it will atomize and help cool the inlet charge temperature. Water-methanol is essentially windshield wiper fluid, but usually a different concentration. The effects of this mixture are most prevalent in a supercharged/turbocharged application where one psi of compressed air usually equates to around a ten degree fahrenhieght increase of inlet temp in a nonintercooled/aftercooled application. The idea behind the decreased inlet temp is to be able to run a greater spark timeing advance thus generating greater gains in power. Considering the fact that it is supposed to be a mixture of water and methanol and sprayed in a thin vapor to atomize with atmosphere and fuel there should be relatively little opportunity to foul electronics. Also of note, the car should be retuned with a chasis dynomometer to realize the full potential of this upgrade. Finally before I lock my mouth up, fuel economy is a dynamic solution to the formula of driving input referenced to mechanical efficiency as well as driving conditions. Atmosheric density and temperature as well as hills valleys turns etc. also play critical roles in determining fuel consumption. The greatest factor is throttle load. The rpms may not get that high (shifting at 3-3.5k) but the throttle load under normal driving conditions is greater with lower rpm. If you are in to high of a gear at to low of speed then you will need to apply an increase in throttle even to maintain a constant speed. As far as the effect of a performance air filter is concerned, a perf. filter should provide an increase in fuel efficiency by the theory that with an increase in mechanical efficiency there is a decrease in fuel consumption (provided that the performance filter does flow a greater volume of air than a different filter that it is being compared with). Consider this, a brand new OEM filter outflows the same airfilter with 200K miles on it and is encrusted with mud correct? That being said, if the K&N (or other performance filter) truley does flow a greater volume of air, then by the simple fact that it increases the mechanical and adiabetic efficiency of the engine, it should not decrease the fuel consumption. That being said, in reality there should be almost no difference between most filters, as long as they are quality, clean filter. Good night ladies and gentlemen

Originally Posted by henryshih

SOME WEIRD THING HAPPEN ON THIS WEEKEND....

I FILL UP THE WHOLE TANK WITH A BOTTLE OF INJECTOR CLEANER WHICH I BOUGHT FROM COSTCO AND HAD SMALL RIDE TO LONG BEACH AND BACK ABOUT 100 MILES IN DISTANCE. I HAD AN ERROR CODE PO0365 WHICH SHOW ME EXHAUST CAMSHAFT POSITION SENSOR WAS NOT WORKING PROPERLY. THIS CODE HAS BEEN ON AND OFF FOR MONTHS (MOSTLY ON). UNTILL I FINALLY PURCHASE THIS PART AND HAD ARRIVED ON SUNDAY.

ANYWAY, I DECODED BEFORE THE RIDE AND NOTICED THE CHECK LIGHT HAS NOT BEEN ON FOR THE ENTIRE TRIP AND ON BOARD COMPUTER SHOWS ME 26 MPG INSTEAD OF 18 WHICH I HAD BEFORE...... OF COURSE , MY RIDE IS ABOUT 90 % FREEWAY AT 70 MPH.

DO I STILL NEED TO REPLACE THE SENSOR..??

DOES THE INJECTOR CLEANER REALLY HELPED HERE...???

I ALSO BOUGHT ACTRON CP9575 AND I WILL RUN THE ENGINE BEFORE ANY CHANGES.

Holy caps! No need to shout.

Always check MAF and O2 sensor, those can play a large part in your mpg. Personally, I don't trust those "miracle in a bottle" solutions. Nevertheless, I do have some belief in Seafoam when cleaning carbon out of the engine, through I haven't done it on the BMW yet it has helped some of my higher mileage cars.

When replacing the O2 sensor on my Honda winter beater, the mpg did improve and I esentially got it for free from the junkyard (I actually got a couple )

Originally Posted by j0n228

hi guys i got 120k miles on my car and im getting 17.5 mpg i wanted to know what the best thing to do to help improve mpgs besides driving slower like what can i change to help improve this and get it to where its sapouse to be like 23 mpgs

GET NEW CAR....economy car.

I sold my daily driver Jeep wrangler on 37" tires, so anything over 10mpg is a blessing for me!! Lol.

The '01 325i that I now drive has about 135k miles on it. Its getting decent mileage, but now that Premium is at $4.00 a gallon, I'm ready to try & figure out how tovsave a buck. Do any fuel additives help? I saw someone mention seafoam. What about gas? Does premium help? Does regular hurt?

My last tank (almost empty) has been 89. My next one is going to be 87. Know a guy who works as a tech at a BMW dealer and drives an E9X and puts in 87. It won't hurt, especially not your wallet.

BTW I maybe lost 0.2-0.3 L/100 Km (which is just over 1 Mi/USG) in going to 89 octane, however a lot of the driving was in windy conditions which adversely affects mileage as well. Just be glad you're not buying gas in Canada, you guys in the states with your American Peso have it good

My brother has a 325i with 107k on it he's owned it since 45k and has used 87octane it's whole life and changed his oil every 10k and it has not had a problem yet, me on the other hand had my.car with 48k and now am at 63k and have only used 91 and changed oil every 5k and he gets more
MPG than me but im not B1tching about gas since I knew I wasn't buying a prius

Originally Posted by reez777

I'm not sure if this will work for all E46 owners, but I increased my MPG from 20 to 25.5 by doing two things

i) taking the spare wheel out of the car.
ii) taking my girlfriend out of the car.

Weight Loss of the two items combined was enough to get my MPG shooting up.

LMAO!!!

Originally Posted by Dedney

I sold my daily driver Jeep wrangler on 37" tires, so anything over 10mpg is a blessing for me!! Lol.

The '01 325i that I now drive has about 135k miles on it. Its getting decent mileage, but now that Premium is at $4.00 a gallon, I'm ready to try & figure out how tovsave a buck. Do any fuel additives help? I saw someone mention seafoam. What about gas? Does premium help? Does regular hurt?

I feel your pain on the Wrangler...