Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series / 4 Series > E46 (1999 - 2006)

E46 (1999 - 2006)
The fourth generation 3 Series (E46 chassis) was introduced in 1999 and set the standard for engineering and performance during it's years of production including being named to Car & Driver's 10 best list every one of those years! ! -- View the E46 Wiki

Reply
 
Thread Tools Display Modes
  #1  
Old 01-17-2013, 01:56 PM
sa21189 sa21189 is offline
Officially Welcomed to the 'Fest
Location: USA
 
Join Date: Feb 2009
Posts: 135
Mein Auto: 325xi
how to get the best mileage?

I have an 04' 325xi and right now the mileage is killing me. I've been averaging about 19.4 on the highway, does anyone know how I can do better?
Reply With Quote
Ads by Google
  #2  
Old 01-17-2013, 02:06 PM
Fast Bob's Avatar
Fast Bob Fast Bob is offline
Keeping it surreal
Location: Here, there, everywhere....
 
Join Date: Jun 2004
Posts: 34,087
Mein Auto: 2004 330Ci ZHP 3 pedals
That`s pretty poor *for highway mileage*....most of us get high twenties to low thirties depending on our personal driving habits. How do you calculate your mileage ?
You should pull the plugs to see what they look like....if they`re a nice light greyish-tan color, that would indicate a healthy burn condition....darker, oily plugs are indicative of other things, like maybe a failing CVV.
__________________
The road goes ever onward....
(R.I.P. Jever)

*Please support the Wounded Warrior Project*

When faced with choosing between two evils, always go with the one you`ve never tried before....
Reply With Quote
  #3  
Old 01-17-2013, 03:09 PM
sa21189 sa21189 is offline
Officially Welcomed to the 'Fest
Location: USA
 
Join Date: Feb 2009
Posts: 135
Mein Auto: 325xi
Thanks for the reply. I could be totally wrong, but I'm going off of what my dashboard tells me. It says 19.4 mpg which I've assumed is my mileage. What do you mean by the plugs?
Reply With Quote
  #4  
Old 01-17-2013, 03:36 PM
cwsqbm's Avatar
cwsqbm cwsqbm is offline
Dreaming of Track Days
Location: Somewhere in the aether
 
Join Date: Aug 2004
Posts: 10,044
Mein Auto: ED'd 330Ci / E30 325i
Quote:
Originally Posted by sa21189 View Post
Thanks for the reply. I could be totally wrong, but I'm going off of what my dashboard tells me. It says 19.4 mpg which I've assumed is my mileage. What do you mean by the plugs?
Have you recently reset the mpg indicator (press the mode button to display the mpg, then press and hold it until it resets)? If not, that 19.4 is a long term average, not just what you're getting on the highway, and is a reasonable for a suburban or urban environment. Get on the highway on a relatively flat and straight stretch, and then reset the OBC and see what you car is really capable on the highway.
__________________
.................................................. ............................................. Space for rent .................................................. ..........................................

Last edited by cwsqbm; 01-17-2013 at 03:43 PM.
Reply With Quote
  #5  
Old 01-17-2013, 04:03 PM
sa21189 sa21189 is offline
Officially Welcomed to the 'Fest
Location: USA
 
Join Date: Feb 2009
Posts: 135
Mein Auto: 325xi
Thanks for the replies! I've heard that there are some ways to increase your gas mileage by inflating tires and such, can anyone give me some tips on that?
Reply With Quote
  #6  
Old 01-17-2013, 04:07 PM
SJBimmer's Avatar
SJBimmer SJBimmer is offline
Living Life At The Beach
Location: In This Place
 
Join Date: Feb 2007
Posts: 3,810
Mein Auto: 2004 325 Convertible
You might gain 1 mpg by over inflating the tires, but it's all of the 4wd hardware that is killing your mileage. Winter mileage will always be less, due to cold weather inefficiency.
Reply With Quote
  #7  
Old 01-17-2013, 04:07 PM
cwsqbm's Avatar
cwsqbm cwsqbm is offline
Dreaming of Track Days
Location: Somewhere in the aether
 
Join Date: Aug 2004
Posts: 10,044
Mein Auto: ED'd 330Ci / E30 325i
Quote:
Originally Posted by sa21189 View Post
Thanks for the replies! I've heard that there are some ways to increase your gas mileage by inflating tires and such, can anyone give me some tips on that?
Don't over-inflate your tires. Just make sure they are at the proper pressures.

Number one fuel saving technique is to drive slower.
__________________
.................................................. ............................................. Space for rent .................................................. ..........................................
Reply With Quote
  #8  
Old 01-17-2013, 04:43 PM
QAfred QAfred is offline
Officially Welcomed to the 'Fest
Location: Panhandle of Florida
 
Join Date: Aug 2008
Posts: 909
Mein Auto: 328i, 330ci, R1200C
Quote:
Originally Posted by sa21189 View Post
Thanks for the reply. I could be totally wrong, but I'm going off of what my dashboard tells me. It says 19.4 mpg which I've assumed is my mileage. What do you mean by the plugs?
spark plugs

Quote:
Originally Posted by cwsqbm View Post
Have you recently reset the mpg indicator (press the mode button to display the mpg, then press and hold it until it resets)? If not, that 19.4 is a long term average, not just what you're getting on the highway, and is a reasonable for a suburban or urban environment. Get on the highway on a relatively flat and straight stretch, and then reset the OBC and see what you car is really capable on the highway.
+1, also, you need to check your average MPH..duh, c'mon man!
There is a direct correlation between your avg MPH and your MPG. I drive 80 miles a day round trip to work and get 28.00MPG, on my 330ci, but my avg speed is 45.6
Look at your average MPH and reset it the same time you reset your MPG as MPG is definitely impacted by city vs rural driving- I am obviously more rural with an overall average of 45.6.
Reply With Quote
  #9  
Old 01-17-2013, 05:13 PM
OfTheLost's Avatar
OfTheLost OfTheLost is online now
Officially Welcomed to the 'Fest
Location: VA
 
Join Date: Jul 2012
Posts: 578
Mein Auto: 2000 328i
Ive heard that trading in for a camry can boost those mpg's...

You have a bmw, and an all wheel drive at that, why are you even worried about it?
__________________
Reply With Quote
  #10  
Old 01-17-2013, 05:17 PM
Jimmys 530i Jimmys 530i is offline
Officially Welcomed to the 'Fest
Location: Conyers, GA
 
Join Date: Feb 2011
Posts: 811
Mein Auto: 2003 530i
I get 27-31 mpg on my 330ci. I leave it in 6th gear and use the cruise control. The majority of my driving is on rural country roads, going about 70-75 mph.
__________________
2004 BMW 330ci Silvergray Sport Package, Cold Package, Xenon Headlamps, Premium Package, 6 Speed Manual, Build Date 9/03

Sold - 2003 325i Sedan Japanrot 5 Speed 8k Xenon Headlamps Build Date 11/02
Reply With Quote
  #11  
Old 01-17-2013, 05:52 PM
Siskin's Avatar
Siskin Siskin is offline
Device Under Test
Location: Central Pennsylvania
 
Join Date: Sep 2012
Posts: 274
Mein Auto: '04 325xi
Quote:
Originally Posted by sa21189 View Post
Thanks for the replies! I've heard that there are some ways to increase your gas mileage by inflating tires and such, can anyone give me some tips on that?
Do make sure your tires are properly inflated. Do not overinflate them.

There are all sorts of crazy ways to increase your mpg, but none better than making sure your car is running as it was designed to.

A loss of mpg is typically resultant of a drop in power. Thus necessitating more work be done by the engine to move the vehicle a given distance. Typically, this is due to one of three things performing below specifications: your volumetric efficiency, combustion efficiency, and mechanical efficiency. Toss in mean effective pressure in case you have a compression issue.

Volumetric efficiency is related to how well your cylinders draw in fuel and air during the induction stroke. Verify that your air filter is not restricting incoming air and that your fuel filter or injectors are not restricting your fuel. Running rich or lean will hurt mpg.

Combustion efficiency is related to how completely the air/fuel mixture burns upon ignition. Lack of total combustion could signal issues with the spark plugs but could also be a lack of sufficient vaporization of the fuel within the air component of the mixture. This again points to injectors.

Finally, mechanical efficiency is, of course, the percentage of work produced by the engine which is actually used to move your car forward and overcome counteracting forces. This is where tire pressure comes into play. Lower tire pressure adds rolling resistance and thus leaches some of your power. Compared to the other items on this list, it's a relatively low culprit. Good lubrication is essential to maintaining peak mechanical efficiency.

Finally, mean effective pressure - if you don't have good compression because of a blown head gasket or something, you won't be able to harness the explosive pressure exerted on the piston and effectively transfer the combustion into work. It's like blowing up a balloon with a hole in it.

To summarize, check your plugs.
__________________
Siskin | 2004 BMW 325xi ZPP/ZCW

Enough miles to make it to the moon... Here's to getting home.
Reply With Quote
  #12  
Old 01-17-2013, 06:00 PM
Siskin's Avatar
Siskin Siskin is offline
Device Under Test
Location: Central Pennsylvania
 
Join Date: Sep 2012
Posts: 274
Mein Auto: '04 325xi
Correction: a loss in power will not necessitate more work be done by the engine to move the car a given distance. What I should have said was that more chemical energy will be required to produce the same amount of mechanical work.

Unless the problem is with mechanical efficiency - then my original statement stands.
__________________
Siskin | 2004 BMW 325xi ZPP/ZCW

Enough miles to make it to the moon... Here's to getting home.
Reply With Quote
  #13  
Old 01-17-2013, 06:04 PM
Fast Bob's Avatar
Fast Bob Fast Bob is offline
Keeping it surreal
Location: Here, there, everywhere....
 
Join Date: Jun 2004
Posts: 34,087
Mein Auto: 2004 330Ci ZHP 3 pedals
Quote:
Originally Posted by sa21189 View Post
Thanks for the reply. I could be totally wrong, but I'm going off of what my dashboard tells me. It says 19.4 mpg which I've assumed is my mileage. What do you mean by the plugs?
That AVG mileage figure has been accumulated over umpteen-thousand miles since the last time it was reset to ZERO. It doesn`t reflect your current situation at all....
__________________
The road goes ever onward....
(R.I.P. Jever)

*Please support the Wounded Warrior Project*

When faced with choosing between two evils, always go with the one you`ve never tried before....
Reply With Quote
  #14  
Old 01-17-2013, 06:13 PM
jvr826's Avatar
jvr826 jvr826 is offline
Is it Trackday yet?
Location: In the woods. Santa Cruz County, CA
 
Join Date: Apr 2002
Posts: 8,830
Mein Auto: 05 330ci 6MT
+1, but also... are you running 91 or higher octane fuel?
__________________
Jeff R.
Golden Gate Chapter BMW CCA - Autocross - Come Join Us!


"You drive like old people $#@%... slow and sloppy!" - George Carlin
Reply With Quote
  #15  
Old 01-18-2013, 09:15 AM
Dave 330i's Avatar
Dave 330i Dave 330i is offline
The King of Common Sense
 
Join Date: Jan 2002
Posts: 93
Send a message via Skype™ to Dave 330i
Mein Auto:
Try this. It will not take up too much time to accomplish. When you are on a clear freeway, drive at a constant speed, say 65mph. Scroll the OBC to mpg, reset it, then drive for a minute or so. You should get mpg reading of around 30mpg or a little greater. If not, then you have a problem.
__________________
Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid. Albert Einstein

Swim upstream. Go the other way. Ignore the conventional wisdom. If everybody is doing it one way, there’s a good chance you can find your niche by going exactly in the opposite direction", Sam Walton.

Last edited by Dave 330i; 01-18-2013 at 09:17 AM.
Reply With Quote
  #16  
Old 01-18-2013, 02:55 PM
E46_Ci E46_Ci is offline
Officially Welcomed to the 'Fest
Location: Portland, OR
 
Join Date: May 2010
Posts: 741
Mein Auto: 2005 325Ci + ZPP/ZSP/ZCW
Manually calculating your MPG is the best way to get per tank numbers and average overtime... I use Fuelly every time I fill up and it keeps track for me... it is fairly close to my OBC, off by about 0.2mpg between the Fuelly and OBC.
__________________

Alpinweiß 2005 325Ci
Spacegrau 2007 X5 3.0Si

Reply With Quote
  #17  
Old 01-18-2013, 04:37 PM
sa21189 sa21189 is offline
Officially Welcomed to the 'Fest
Location: USA
 
Join Date: Feb 2009
Posts: 135
Mein Auto: 325xi
how do i reset the OBC?
Reply With Quote
  #18  
Old 01-18-2013, 05:21 PM
Fast Bob's Avatar
Fast Bob Fast Bob is offline
Keeping it surreal
Location: Here, there, everywhere....
 
Join Date: Jun 2004
Posts: 34,087
Mein Auto: 2004 330Ci ZHP 3 pedals
Quote:
Originally Posted by sa21189 View Post
how do i reset the OBC?
With the key on, toggle over to the AVG MPG function, and just hold the stalk button down until the readout goes to __ __ __....This can be done while standing still or on the fly.
__________________
The road goes ever onward....
(R.I.P. Jever)

*Please support the Wounded Warrior Project*

When faced with choosing between two evils, always go with the one you`ve never tried before....
Reply With Quote
  #19  
Old 01-18-2013, 10:53 PM
lgr122 lgr122 is offline
Officially Welcomed to the 'Fest
Location: Finland
 
Join Date: Aug 2012
Posts: 1,257
Mein Auto: BMW e46 1,9l M43
Quote:
Originally Posted by E46_Ci View Post
Manually calculating your MPG is the best way to get per tank numbers and average overtime... I use Fuelly every time I fill up and it keeps track for me... it is fairly close to my OBC, off by about 0.2mpg between the Fuelly and OBC.
That's what i do. Calculate manually.
Always write down mileage when i fill up and how much fuel exactly went in. I have note book for the purpose, also writing down mileage of each service procedure, that way it's easy to check afterwards what was done when.

Last edited by lgr122; 01-18-2013 at 10:54 PM. Reason: Bad english
Reply With Quote
  #20  
Old 01-19-2013, 04:20 AM
alfabmw1 alfabmw1 is offline
Officially Welcomed to the 'Fest
Location: Massachusetts
 
Join Date: Jun 2010
Posts: 199
Mein Auto: 2001 325 xi
It may depend on where you live and what time of year it is. I do not do a ton of highway driving, mostly back roads, but normally I get around 23mpg. At least until winter hits. I live north of Boston, and when January and February roll around, I have seen my millage drop to 18. I attribute it to winter gas, but more to the fact that I have to haul around a transfer case, and all the outer running gear for an xi.
We had a warm spell here, and during that time my millage improved.

So if you are in a cold climate, see how the car does in the spring. In the mean time, definitely follow the advice from the other folks.
__________________
Reply With Quote
  #21  
Old 01-20-2013, 08:26 AM
kbeamer's Avatar
kbeamer kbeamer is offline
Officially Welcomed to the 'Fest
Location: Pennsylvania
 
Join Date: Nov 2010
Posts: 374
Mein Auto: 2002 330ci
Frankly 19.4 is extremely low. Do you stick to a steady speed? I just did a 250 mile trip this weekend doing anywhere from 75 to 85 all highway and had 29 to 32 mpg. I did inflate my tires before leaving but I doubt that had much to do with it.

In June I made a trip to myrtle beach sc to our second home which is over 9 hours away an averaged over 34 mpg driving a steady 80-85mph on the highway. I am always careful I leave my foot steady. If your constantly dropping your foot to gain speed your mpg go way down.

Things I have done, replace spark plugs, filters, and fuel filter. I did gain mpg after replacing my fuel filter. And I always leave for a trip with a full tank if gas and recent my miles through my nav screen.

Good luck!
Reply With Quote
  #22  
Old 01-20-2013, 09:39 AM
E46landshark's Avatar
E46landshark E46landshark is offline
Prowlin
Location: Oklahoma
 
Join Date: Jan 2013
Posts: 197
Mein Auto: 2004 325ci
Quote:
Originally Posted by DAQman View Post
Do make sure your tires are properly inflated. Do not overinflate them.

There are all sorts of crazy ways to increase your mpg, but none better than making sure your car is running as it was designed to.

A loss of mpg is typically resultant of a drop in power. Thus necessitating more work be done by the engine to move the vehicle a given distance. Typically, this is due to one of three things performing below specifications: your volumetric efficiency, combustion efficiency, and mechanical efficiency. Toss in mean effective pressure in case you have a compression issue.

Volumetric efficiency is related to how well your cylinders draw in fuel and air during the induction stroke. Verify that your air filter is not restricting incoming air and that your fuel filter or injectors are not restricting your fuel. Running rich or lean will hurt mpg.

Combustion efficiency is related to how completely the air/fuel mixture burns upon ignition. Lack of total combustion could signal issues with the spark plugs but could also be a lack of sufficient vaporization of the fuel within the air component of the mixture. This again points to injectors.

Finally, mechanical efficiency is, of course, the percentage of work produced by the engine which is actually used to move your car forward and overcome counteracting forces. This is where tire pressure comes into play. Lower tire pressure adds rolling resistance and thus leaches some of your power. Compared to the other items on this list, it's a relatively low culprit. Good lubrication is essential to maintaining peak mechanical efficiency.

Finally, mean effective pressure - if you don't have good compression because of a blown head gasket or something, you won't be able to harness the explosive pressure exerted on the piston and effectively transfer the combustion into work. It's like blowing up a balloon with a hole in it.

To summarize, check your plugs.
Beautifully broken down. +1. Any specific brand you guys would recommend through personal experience, or is there a pretty clear choice for the best spark plugs? I'm looking to get some today after work.
Reply With Quote
  #23  
Old 01-20-2013, 11:30 AM
TannerT TannerT is offline
Officially Welcomed to the 'Fest
Location: Columbia, Missouri
 
Join Date: Mar 2012
Posts: 966
Mein Auto: 03 330ci 3pdl 89 325i
Bosch and NGK all day

Sent from my PantechP9060 using Bimmer App
__________________
sFormula SAE "Speed is Sexy"
Reply With Quote
  #24  
Old 01-20-2013, 12:18 PM
E46landshark's Avatar
E46landshark E46landshark is offline
Prowlin
Location: Oklahoma
 
Join Date: Jan 2013
Posts: 197
Mein Auto: 2004 325ci
I'm guessing we have wiki on how to change the plugs? I've only been under the hoods of Hondas. Same concept ?(remove head, Badda bing its right there)



Edit: found ten DIY movies, disregard the question.

Last edited by E46landshark; 01-20-2013 at 12:59 PM.
Reply With Quote
  #25  
Old 01-20-2013, 05:04 PM
mawana's Avatar
mawana mawana is offline
Officially Welcomed to the 'Fest
Location: DFW, TX
 
Join Date: Nov 2006
Posts: 2,022
Mein Auto: e46 ZHP, e90 M3
Quote:
Originally Posted by OfTheLost View Post
Ive heard that trading in for a camry can boost those mpg's...
lol
__________________
"Common sense is the collection of prejudices acquired by age 18." ~ Albert Einstein
BMWCCA 405578
Reply With Quote
Reply

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series / 4 Series > E46 (1999 - 2006)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On



Forum Jump


All times are GMT -7. The time now is 10:25 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms