Need advice improving gas mileage
07-26-2012, 04:30 PM
#1
I have a second hand 2004 530i. Gas mileage is rated 20/30 mpg, but the computer tells me I'm going a little over 15 mpg. How do I diagnose what needs to be replaced to improve my gas mileage?
07-26-2012, 05:08 PM
#3
Contributors
Join Date: Dec 2007
Location: The State of Southern NJ!
Posts: 5,972
Likes: 0
Received 0 Likes
on
0 Posts
07-26-2012, 05:17 PM
#4
Car is stock
Wheels are stock
Going to check tires today
Maintenance history looked like it was really cared for in the Carfax
Only has about 25k miles on it
Driving conditions: mostly city, but in Hawaii there's a lot of traffic, so that might be the cause of it
Driving style: I try to be as conservative as possible
Wheels are stock
Going to check tires today
Maintenance history looked like it was really cared for in the Carfax
Only has about 25k miles on it
Driving conditions: mostly city, but in Hawaii there's a lot of traffic, so that might be the cause of it
Driving style: I try to be as conservative as possible
07-26-2012, 05:50 PM
#6
Senior Members
Join Date: Oct 2006
Location: Colorado USA
Posts: 518
Likes: 0
Received 0 Likes
on
0 Posts
My Ride: 2004 545i, 6-speed Manual, Silver Grey Metallic, Grey Dakota Leather, Cold Weather Pkg, Premium Sound Pkg, Sport Pkg, Lumbar Support
1. Did you reset the trip computer to begin a fresh calculation? I think you press and hold the BC button while the display is on Avg MPG to accomplish this. There's also a secondary Trip Computer in the Car Data section of iDrive. This is reset by pressing Set and selecting the Reset function. This will accumulate miles driven, time driven and avg mpg. since the last reset. Also, you can leave this page displayed and see a "real time" calculation of the fuel performance.
2. Most will recommend doing an actual miles driven divided by fuel used calculation instead of using the built-in computer for the most accurate reading.
3. Above recommended tire pressures (check the Max Pressure allowed on the sidewall of the tire), low-rolling resistance tires, reduce extra vehicle weight (junk in the trunk), clean engine air filter, use Premium grade gas, no "jack rabbit" starts, coast to a stop rather than charging up to a stop and using heavy braking, transmission in Drive mode, not Sport mode, limit idling time, etc. Mostly common sense driving habits.
Can't comment about the 530i, but I average 23-24 mpg in my 2004 545i with 52,000 miles. This is in Colorado between 6,000-7,000 feet altitude, which will improve fuel economy maybe 10-15 %.
2. Most will recommend doing an actual miles driven divided by fuel used calculation instead of using the built-in computer for the most accurate reading.
3. Above recommended tire pressures (check the Max Pressure allowed on the sidewall of the tire), low-rolling resistance tires, reduce extra vehicle weight (junk in the trunk), clean engine air filter, use Premium grade gas, no "jack rabbit" starts, coast to a stop rather than charging up to a stop and using heavy braking, transmission in Drive mode, not Sport mode, limit idling time, etc. Mostly common sense driving habits.
Can't comment about the 530i, but I average 23-24 mpg in my 2004 545i with 52,000 miles. This is in Colorado between 6,000-7,000 feet altitude, which will improve fuel economy maybe 10-15 %.
07-26-2012, 07:45 PM
#7
Senior Members
Join Date: Jan 2011
Location: Thousand Oaks, CA
Posts: 361
Likes: 0
Received 0 Likes
on
0 Posts
My Ride: 2004 BMW 545i Silver,Gray, Metallic. Blk Dakota leather. Nav. Heads up disply. PDC. Pro logic 7 sound. 35% tint.
Mods. MTECH body kit. OEM trunk finisher and M5 spoiler.OEM 166 wheels. Blk and wht CF Roundels.
Orion V2 AEs. LCI taillights with Ricky effect. LED interior lights. LED license plate light. HID fogs. Smoked LED side markers. White cluster mod. Coding. RPI scoop & BMC filter. Gloss black OEM grills.CF interior trim. B&B exhaust.
1. Did you reset the trip computer to begin a fresh calculation? I think you press and hold the BC button while the display is on Avg MPG to accomplish this. There's also a secondary Trip Computer in the Car Data section of iDrive. This is reset by pressing Set and selecting the Reset function. This will accumulate miles driven, time driven and avg mpg. since the last reset. Also, you can leave this page displayed and see a "real time" calculation of the fuel performance.
2. Most will recommend doing an actual miles driven divided by fuel used calculation instead of using the built-in computer for the most accurate reading.
3. Above recommended tire pressures (check the Max Pressure allowed on the sidewall of the tire), low-rolling resistance tires, reduce extra vehicle weight (junk in the trunk), clean engine air filter, use Premium grade gas, no "jack rabbit" starts, coast to a stop rather than charging up to a stop and using heavy braking, transmission in Drive mode, not Sport mode, limit idling time, etc. Mostly common sense driving habits.
Can't comment about the 530i, but I average 23-24 mpg in my 2004 545i with 52,000 miles. This is in Colorado between 6,000-7,000 feet altitude, which will improve fuel economy maybe 10-15 %.
2. Most will recommend doing an actual miles driven divided by fuel used calculation instead of using the built-in computer for the most accurate reading.
3. Above recommended tire pressures (check the Max Pressure allowed on the sidewall of the tire), low-rolling resistance tires, reduce extra vehicle weight (junk in the trunk), clean engine air filter, use Premium grade gas, no "jack rabbit" starts, coast to a stop rather than charging up to a stop and using heavy braking, transmission in Drive mode, not Sport mode, limit idling time, etc. Mostly common sense driving habits.
Can't comment about the 530i, but I average 23-24 mpg in my 2004 545i with 52,000 miles. This is in Colorado between 6,000-7,000 feet altitude, which will improve fuel economy maybe 10-15 %.
07-27-2012, 03:57 AM
#9
Senior Members
Join Date: Oct 2006
Location: Colorado USA
Posts: 518
Likes: 0
Received 0 Likes
on
0 Posts
My Ride: 2004 545i, 6-speed Manual, Silver Grey Metallic, Grey Dakota Leather, Cold Weather Pkg, Premium Sound Pkg, Sport Pkg, Lumbar Support
Manual transmission, high altitude, mostly highway (2/3 highway, 1/3 city) and, of course, easy on the throttle. Not a lot of WOT. Some, just enough to enjoy the car.
07-27-2012, 06:36 AM
#10
Contributors
Join Date: Sep 2007
Location: Encino, CA
Posts: 1,712
Likes: 0
Received 0 Likes
on
0 Posts
My Ride: 04 545i - Titanium Silver/Black, Sport pkg, Comfort Seats w/ Lumbar, Premium Sound, power rear sunshade, Adaptive Xenon Headlights, Steptronic, Park Distance Control, Fold down rear seats w/ski bag, Aux jack, 6-disk changer, puddle lamps...
Engine: Custom Remus cat-back exhaust w/chrome square tips, K&N Air Filter, Charcoal Filter Removed, Sprint Booster :-), 50/50 mix of 91+100 Octane, EuroRev ECU Remap (coming soon lol), Dinan High-Flow Throttle Body (coming soon...maybe lol)
Interior: Portable Sirius Stilletto 100 w/car kit, Garmin Nuvi 680 mounted below rear-view mirror, LCI-style I-drive knob, Dark Poplar Center Dashboard Trim.
Exterior: E60 forum clings, 5% rear tint, ACS roof spoiler (painted black for distinct look against limo tint), ACS trunk spoiler, ACS add-on front spoiler and rear apron (awaiting installation), "18 Black Staggered BeBeS Style OER (emergency replacement for cracked sport 124 rims), black kidney grill, white accessory lighting (including license and trunk lamps), Angel-eye upgrade, AIB xenon-matched fog lamps, AIB V3's on order, red rear reflectors
I average around 21 in my 545. I do a bit of highway driving daily. Our cars have a handy lil engine load vacuum-based instant mpg guage. Sitting and crawling through traffic will get you well under 15mpg (and often under 10mpg ). Of course idling = 0mpg. If you sit in traffic as a regular part of your drive, expect to get far less mpg than you would from a balanced mix of city/highway (and far fewer than mostly highway).