[soflop]

Originally Posted by LaLakers91tc

did you try some general maintainence?
using a fuel system cleaner like Chevron Techron, or Lucas cleaner is a good idea, and some maf cleaner could help a bit too. Other than that, change your driving habits
I have got 24 mpg doing 70% local when I consciously tried to conserve momentum, go easy on gas, and brake gently, but when I have some illegal fun I easily go back down to 15 mpg on same breakdown of roads

I actually thought of using some fuel system cleaner but I didnt wanna take any risks cause I really dont know too much about these cars. I'm new to BMW and I know they're much more sophisticated than what I'm used to (Toyota, older Lexus', Ford, etc), so I'm not sure man.
Do you know of anyone who's ever done this?
It shouldn't be the way I drive either. My previous car, 2002 Camry (95K miles) was averaging 21 mpg and I drive exactly the same and to the same places. Hardly ever do I get carried away with the throttle, definitely not enough to average what I am.

Originally Posted by Tom K.

Soflop, you have an E90, not an E46 and there is no recommended service at 40,000 miles - ignore that link and check out your Warranty/service manual for recommended services. Also, did you get a service history of your car when you bought it? If not, a BMW dealer should be able to provide that info for you.

While resetting your BC MPG readout will not improve your mileage, it will update it. I reset mine each fillup but also calculate mpg the old fashioned way for each tank - miles divided by gallons. Recording the BC figure also allows me to double check the computer which (on my 2 current BMWs) is accurate to within 2%.

My 328i wagon (MT, RWD) is averaging around 20 in town, 29 on the road and about 24 overall. With all wheel drive (in Miami?) and Steptronic, yours should be maybe 10~20% lower, and perhaps another 10% lower when using air conditioning. Are you aware that hitting the climate control AUTO button turns on the A/C compressor (button with a snowflake icon). Turning it off when not needed should save some gas.

To check that there isn't a real problem with the car, zero the computer's mpg readout and then drive at least 50 miles in light traffic on an interstate at a steady 65~70 mph. You should see at least 25 mpg if not better.

Tom

Thanks for the info Tom, very helpful. I saw the link and i wasn't too convinced for the same fact you brought up; E46 :/
I would need to go to the dealer and get that service history to know whats going on, and perhaps (if available) maintenance requirements for the amount of miles.
Yea, I live in Miami and yea it's usually pretty warm down here lol but the A/C shouldn't make such a significant difference to gas mileage. I don't see why just using the "Auto" feature would engage the compressor clutch. To my knowledge, when the A/C is on, it should engage the clutch (I'm not saying you're incorrect cause like I mentioned earlier, I don't know jack about these cars but at least vehicles I've worked on, when the A/C is turned on the clutch engages). Either way, I never use Auto, it gets the A/C at full blast lol
Whenever i fill my tank, the computer says I have >300 miles left till next fill. RIGHT NOW I'm by 181 miles and its marking 42 mls, and by the looks of it, I doubt I'll even reach 220 mls. (thats just usually how it is)


BY THE WAY!!
Today I was driving home from work and while stopped at a red light, when I went to take off THE CAR DIDNT MOVE!!!! IT WAS LIKE THE CAR WAS IN NEUTRAL!!! WTF!!!??? It took about two seconds before it moved. (happened twice!!!) DOES ANYONE KNOW WHY?

[mike-y]

did the engine just rev, like it wasn't connected to anything? or did the car just not move, like the brakes were still on?

[tray1o6]

I have an 07 e90 328 and averaged about 25-26mpg (combined) and then did the carbon filter delete in the intake and noticed that I now average between 28-32mpg (combined). I'm a pretty aggressive driver but I get to my cruising speed and lay off the accelerator (pressing it just enough to barely hold speed). But I do have a 20mi commute to work that's all hwy. Getting about 35hwy/25city on average

[soflop]

Originally Posted by mike-y

did the engine just rev, like it wasn't connected to anything? or did the car just not move, like the brakes were still on?

yea it kinda felt like it was in neutral

Originally Posted by tray1o6

I have an 07 e90 328 and averaged about 25-26mpg (combined) and then did the carbon filter delete in the intake and noticed that I now average between 28-32mpg (combined). I'm a pretty aggressive driver but I get to my cruising speed and lay off the accelerator (pressing it just enough to barely hold speed). But I do have a 20mi commute to work that's all hwy. Getting about 35hwy/25city on average

im gonna try to take that carbon filter out. i looked at it yesterday and dont see a point to it. 25/35 thats fck**g phenomenal... i wish i got that

[soflop]

This is ridiculous...

[qclik]

my coupe 328xi after the filter delete went up from 14 to 16mpg.
i don't really trust on the mpg, i reset my trip mileages each time fill up at the gas station, and check the number next time when i back for more gas.

[micah_675]

Since no one asked. Do you like to let your car idle for extended periods of time?

Also go to your tail pipe and smell the exhaust, let us know if it smells like gasoline.

[soflop]

Originally Posted by qclik

my coupe 328xi after the filter delete went up from 14 to 16mpg.
i don't really trust on the mpg, i reset my trip mileages each time fill up at the gas station, and check the number next time when i back for more gas.

I think I'm just gonna do that. Heard It from a few people already.

Originally Posted by micah_675

Since no one asked. Do you like to let your car idle for extended periods of time?

Also go to your tail pipe and smell the exhaust, let us know if it smells like gasoline.

I have it idling in park for about 1/2 hour mon. Thru fri. While I'm on lunch. And for about 10 minutes in the morning so it can warm up. And nope, doesn't seem to be running rich.

[soflop]

I've been driving manual and it seems to be getting a little better, the mileage. But it's annoying!! Lol

[outriding9800]

Maybe your torque convertor is not locking up.
If it is not locking up it might cost you 2-3 mpg.

If someone with a similar car can chime in on the RPMS at 60mph.

[berserkerx]

Do you have a lot of things in your car? That could also be an issue get some BG44k that is about the best. It made my talon i had quit starting so roughly. My mpg's keep going up as long as I drive it. I have a 330i though. My readout is about 22.4 right now. Watch the active fuel economy needle and alter your habits a bit. if you do get to highway speeds use cruise and try to let the car coast rather than slamming on the brakes when coming to a red light.

[Lenaxia]

Like someone said, you're probably running rich. Take it into a mechanic and have them check your injectors. Also your torque convertor since you had the neutral issue. You are not going to be able to avoid taking it into a shop.

My 330xi easily is at 280mi by the time I'm down to 1/4 of a tank. thats with mostly local driving.

Trying to diagnose what problem your car has with what little information you've given us isn't going to help.

[soflop]

Originally Posted by outriding9800

Maybe your torque convertor is not locking up.
If it is not locking up it might cost you 2-3 mpg.

If someone with a similar car can chime in on the RPMS at 60mph.

well, i am/was having trouble with the transmission
http://www.e90post.com/forums/showthread.php?t=494157
and the FIRST thing that came to my mind the moment this happened was a faulty torque converter but i never really mentioned it or thought about it anymore cause how likely is it for a TC to fail?? I've never seen one at least.
but i never really thought about it for fuel consumption, VERY good point!!

im gonna have to look for some one with an xi

Originally Posted by berserkerx

Do you have a lot of things in your car? That could also be an issue get some BG44k that is about the best. It made my talon i had quit starting so roughly. My mpg's keep going up as long as I drive it. I have a 330i though. My readout is about 22.4 right now. Watch the active fuel economy needle and alter your habits a bit. if you do get to highway speeds use cruise and try to let the car coast rather than slamming on the brakes when coming to a red light.

I wanna try a fuel additive but but since these cars are so sophisticated, I'm afraid its gonna do something to the fuel system. Just like you did it to your Talon, I would've done it to my SC300 cause its an older car already and I didnt have to worry about anything going wrong AND if something DID go wrong, i knew how to fix it
If someone has done this before to a newer BMW, i need to know how it went

Originally Posted by Lenaxia

Trying to diagnose what problem your car has with what little information you've given us isn't going to help.

What more information do you want?

[sneaks]

I have it idling in park for about 1/2 hour mon. Thru fri. While I'm on lunch. And for about 10 minutes in the morning so it can warm up. And nope, doesn't seem to be running rich.[/QUOTE]

are you joking? your car idles for 40 minutes/day and you can't figure out why your gas mileage sucks?

[soflop]

Originally Posted by sneaks

are you joking? your car idles for 40 minutes/day and you can't figure out why your gas mileage sucks?

wow man... you really think idling makes such an impact on gas mileage? do you know anything about cars? I had the same routine with a 95K mls 2.4L L4 Toyota Camry and a 60K mls 3.0L TT L6 Lexus SC300 and it didnt make a noticeable difference. AND I drove the SH*T out of that SC! 18mpg avg. Camry; 21mpg avg.

[jaceaholic]

Originally Posted by soflop

I have it idling in park for about 1/2 hour mon. Thru fri. While I'm on lunch. And for about 10 minutes in the morning so it can warm up. And nope, doesn't seem to be running rich.

why do you need to warm up your car for 10 minutes?? you dont have to warm it up that long just wait till the idle goes down then you are good to go..

[soflop]

Originally Posted by jaceaholic

why do you need to warm up your car for 10 minutes?? you dont have to warm it up that long just wait till the idle goes down then you are good to go..

Well just because the idle stabilizes doesn't mean it's at operating temperature. The colder the engine temperature is, the less fuel efficient it'll be.

[sneaks]

what about the 1/2 hour at lunch. what is that for?

[berserkerx]

^^^
Also wondering why that you idle for 30 minutes at lunch? I start my car then wait for it to idle and dont romp on it till its warm.

Idling wont kill your economy by burning gas your right. But you leave nice deposits all over the engine from idling for so long.

If you can find a place to buy it, buy BG 44k and BG 207. Both are actually certified to be good fuel additives by BMW.

Its weird that you get as many miles out of a full tank that I get out of like 1/2 a tank. I average about 380-400 a tank.

[soflop]

Originally Posted by sneaks

what about the 1/2 hour at lunch. what is that for?

Originally Posted by berserkerx

^^^
Also wondering why that you idle for 30 minutes at lunch? I start my car then wait for it to idle and dont romp on it till its warm.

Idling wont kill your economy by burning gas your right. But you leave nice deposits all over the engine from idling for so long.

sit in my car, eat my lunch, listen to the radio, A/C...

Originally Posted by berserkerx

If you can find a place to buy it, buy BG 44k and BG 207. Both are actually certified to be good fuel additives by BMW.

Its weird that you get as many miles out of a full tank that I get out of like 1/2 a tank. I average about 380-400 a tank.

I'm gonna look into the fuel additives.
and yea that mileage is terrible

[Volasko]

Originally Posted by soflop

sit in my car, eat my lunch, listen to the radio, A/C...

If I were you, I would just clear the MPG calculator (hold selector button on top left stalk for at least 5 secs) and report what you get on a highway at cruising speeds (top gear 60-70 mph). Get a clear spot and toss it on cruise control for at least a few mins. If you still can't average around 28ish MPG then you know something is up. I can easily clear 31 MPG that way in my 330i. I know you have AWD and slightly less power but it should be do-able in your car.

I also agree with the theory of long idle times building up carbon around the injectors. Try a reputable cleaner and give the car a good trashing after you du mp the cleaner. Also Idleing while eating does you no good as your car is still counting the fuel used to idle in its MPG calculations.

[soflop]

Originally Posted by Volasko

If I were you, I would just clear the MPG calculator (hold selector button on top left stalk for at least 5 secs) and report what you get on a highway at cruising speeds (top gear 60-70 mph). Get a clear spot and toss it on cruise control for at least a few mins. If you still can't average around 28ish MPG then you know something is up. I can easily clear 31 MPG that way in my 330i. I know you have AWD and slightly less power but it should be do-able in your car.

I also agree with the theory of long idle times building up carbon around the injectors. Try a reputable cleaner and give the car a good trashing after you du mp the cleaner. Also Idleing while eating does you no good as your car is still counting the fuel used to idle in its MPG calculations.

everything you just said, I've done except the fuel treatment. this really blows, i pump every 6 or 7 days