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 > 5 Series > E39 (1997 - 2003)

E39 (1997 - 2003)
The BMW 5-Series (E39 chassis) was introduced in the United States as a 1997 model year car and lasted until the 2004 when the E60 chassis was released. The United States saw several variations including the 525i, 528i, 530i and 540i. -- View the E39 Wiki

Reply
 
Thread Tools Display Modes
  #1  
Old 04-04-2016, 03:08 PM
Wgosma's Avatar
Wgosma Wgosma is offline
Officially Welcomed to the 'Fest
Location: SoCal
 
Join Date: Sep 2009
Posts: 1,611
Mein Auto: 98 528i 5-spd sport pkg
OBC and Fuel Consumption

Ok, this is trivia but who's checked their OBC's MPG and compared to manual calculation after filling the tank and calculating from odo readings? Results?

Thanks/Bill
__________________
Bill / Oceanside, CA
98 528i - 5 spd, Cold Weather Pkg & OEM Sport Suspension
Reply With Quote
Advertisement
  #2  
Old 04-04-2016, 03:13 PM
bobdmac bobdmac is offline
Older than old school
Location: Oaksterdam, Yay Area
 
Join Date: Feb 2011
Posts: 4,405
Mein Auto: 2001 540i/6, '90 k75s
I did this a couple of time on my road trip, and I don't remember the exact figures, but it came out close enough that I was impressed.
__________________
BMW--giving new meaning to the phrase "disposable income."
Reply With Quote
  #3  
Old 04-04-2016, 03:17 PM
Wgosma's Avatar
Wgosma Wgosma is offline
Officially Welcomed to the 'Fest
Location: SoCal
 
Join Date: Sep 2009
Posts: 1,611
Mein Auto: 98 528i 5-spd sport pkg
Bob,
Just tried to PM you...your mailbox is FULL. Anyhow, tell me did you log your total fuel consumption and miles on that trip? I read you were getting mid/high 20's for MPG and was kind of amazed for the V-8.....my 528i will do (on OBC) 31 mpg at best on ALL Highway driving.

Thanks/Bill
__________________
Bill / Oceanside, CA
98 528i - 5 spd, Cold Weather Pkg & OEM Sport Suspension
Reply With Quote
  #4  
Old 04-04-2016, 03:37 PM
bobdmac bobdmac is offline
Older than old school
Location: Oaksterdam, Yay Area
 
Join Date: Feb 2011
Posts: 4,405
Mein Auto: 2001 540i/6, '90 k75s
Re the PM, I just thinned out my mailbox.

Mileage: I calculated the mileage at each fill up, but I haven't gotten around to adding up all my receipts. I think one tank yielded 24 mpg, which disappointed me. Most fill ups were in the 25+ to 27+ mpg, skewed toward the 27+ end of the scale, with one at 30.7 when I filled up with non-ethanol gas in Wyoming. I remember this because when I saw the "non-ethanol" signs at the pumps, I was skeptical that I'd notice a difference, and I couldn't believe it when I got past the 540-mile mark before I started getting nervous about finding a gas station.

Net result, I was surprised at the overall mileage, but this included many miles of 50-60 mph on 2-lane roads, probably the most fuel efficient driving. In town around the Bay Area, I get less than 15 mpg--quite a disparity between highway/freeway driving and city driving.
__________________
BMW--giving new meaning to the phrase "disposable income."
Reply With Quote
  #5  
Old 04-04-2016, 04:46 PM
edjack edjack is online now
Officially Welcomed to the 'Fest
Location: San Jose, CA
 
Join Date: May 2007
Posts: 12,438
Mein Auto: '97 540i 6 speed
I get 15-17 in town, and a solid 24 on the road.
__________________


Ed in San Jose '97 540i 6 speed aspensilber over aubergine leather. Build date 3/97. Golden Gate Chapter BMW CCA Nr 62319.
Reply With Quote
  #6  
Old 04-04-2016, 04:58 PM
Wgosma's Avatar
Wgosma Wgosma is offline
Officially Welcomed to the 'Fest
Location: SoCal
 
Join Date: Sep 2009
Posts: 1,611
Mein Auto: 98 528i 5-spd sport pkg
Bob: 25-27 seems pretty impressive for the V-8.
__________________
Bill / Oceanside, CA
98 528i - 5 spd, Cold Weather Pkg & OEM Sport Suspension
Reply With Quote
  #7  
Old 04-04-2016, 05:12 PM
bobdmac bobdmac is offline
Older than old school
Location: Oaksterdam, Yay Area
 
Join Date: Feb 2011
Posts: 4,405
Mein Auto: 2001 540i/6, '90 k75s
A year ago, on a drive to La Jolla, I got 27+ mpg via I-5. I was tempted to try to make it all the way from Oakland on one tank of gas (485 miles), but I chickened out and stopped in Del Mar, where it took a little more than 17 gallons.
__________________
BMW--giving new meaning to the phrase "disposable income."
Reply With Quote
  #8  
Old 04-04-2016, 05:13 PM
clark49660 clark49660 is offline
Supercharged 540i
Location: Michigan
 
Join Date: Jul 2014
Posts: 421
Mein Auto: 1999 S/C 540i sedan
This is what my OBC said after 358.3 miles after fill-up. On a 1999 Supercharged 540i Automatic. I have never calculated the mileage myself. That's highway driving, Back and forth to work 30 Miles each way.
Attached Thumbnails
Click image for larger version

Name:	photo (1).jpg
Views:	37
Size:	69.8 KB
ID:	557552   Click image for larger version

Name:	photo (2).jpg
Views:	40
Size:	79.7 KB
ID:	557553  
__________________
Reply With Quote
  #9  
Old 04-04-2016, 06:09 PM
QSilver7's Avatar
QSilver7 QSilver7 is offline
Officially Welcomed to the 'Fest
Location: Northeast Indiana
 
Join Date: Aug 2008
Posts: 8,059
Mein Auto: 1997 740iL / 2006 X5 4.4
Quote:
Originally Posted by Wgosma View Post
Ok, this is trivia but who's checked their OBC's MPG and compared to manual calculation after filling the tank and calculating from odo readings? Results?

Thanks/Bill
I do. I keep an Excel file of every fill up. I don't have the charts from my e38 & e39 saved as a jpg...but this question was asked on the e53 forum a few years ago and I happened to get a screen capture of my 2013 e53 fuel costs, tank miles, avg MPH, actual MPG, OBC's MPG, and fuel AKI.

Interestingly...even though the actual & OBC may differ at times....when you get to the end of the year and see the accumulated totals...they aren't that far off:

__________________
Q {BMW CCA Member #191509}
2006 E53 X5 4.4i (Sterling Gray) 12/05 mfg date <<~>> 97 740iL (Arctic Silver) 3/97 mfg date
(SOLD)
99 540iT (Orient Blue) <<~>> 95 525IT (Alpine White)
91 735iL (Schwarz Black) <<~>> 85 325e (Bronzit)

http://imageshack.com/scaled/grid240/822/e38e532ndsigpic.jpg
Reply With Quote
  #10  
Old 04-04-2016, 07:56 PM
Wgosma's Avatar
Wgosma Wgosma is offline
Officially Welcomed to the 'Fest
Location: SoCal
 
Join Date: Sep 2009
Posts: 1,611
Mein Auto: 98 528i 5-spd sport pkg
Very good-thanks for posting!
__________________
Bill / Oceanside, CA
98 528i - 5 spd, Cold Weather Pkg & OEM Sport Suspension
Reply With Quote
  #11  
Old 04-04-2016, 09:44 PM
Sroor9001 Sroor9001 is offline
ALGhoul
Location: Bahrain
 
Join Date: May 2014
Posts: 803
Mein Auto: Bmw 525i 2002
So it's accurate
Reply With Quote
  #12  
Old 04-05-2016, 07:10 AM
QSilver7's Avatar
QSilver7 QSilver7 is offline
Officially Welcomed to the 'Fest
Location: Northeast Indiana
 
Join Date: Aug 2008
Posts: 8,059
Mein Auto: 1997 740iL / 2006 X5 4.4
Quote:
Originally Posted by Sroor9001 View Post
So it's accurate
If that was directed toward me...then yes...the actual MPG vs OBC MPG is close over a long term bases. As you can see in the chart above...by the time you get to the end of the year...the long term averages are only different by .3 tenths:
  • actual MPG: 14.5 (rounded)
  • OBC MPG : 14.8 (rounded)
__________________
Q {BMW CCA Member #191509}
2006 E53 X5 4.4i (Sterling Gray) 12/05 mfg date <<~>> 97 740iL (Arctic Silver) 3/97 mfg date
(SOLD)
99 540iT (Orient Blue) <<~>> 95 525IT (Alpine White)
91 735iL (Schwarz Black) <<~>> 85 325e (Bronzit)

http://imageshack.com/scaled/grid240/822/e38e532ndsigpic.jpg
Reply With Quote
  #13  
Old 04-05-2016, 07:26 AM
pudl's Avatar
pudl pudl is offline
Officially Welcomed to the 'Fest
Location: Wien, Österreich, EU
 
Join Date: Jun 2012
Posts: 840
Mein Auto: E39 530dAT 2001 M-Sport
I keep a spreadsheet of ... everything... over all time. I adjusted the fuel usage multiplier slightly so that the fuel usage readings are now exact.
Reply With Quote
  #14  
Old 04-05-2016, 07:54 AM
mattmar1's Avatar
mattmar1 mattmar1 is offline
Wingnut
Location: Louisiana
 
Join Date: Dec 2014
Posts: 1,004
Mein Auto: 1999 5281 5 sp msport
Quote:
Originally Posted by Wgosma View Post
Ok, this is trivia but who's checked their OBC's MPG and compared to manual calculation after filling the tank and calculating from odo readings? Results?

Thanks/Bill
i dont keep an ongoing file on it, but every so often i do fillup vs miles driven figures. the obc average is pretty accurate, on all hiway drives i get 27, on all around town i get 21. my obc average hovers near 23.
__________________
99 528i 5sp sport, vanos rebuild,coolingoverhaul,stripped/repainted/polished/recoated OEM BBS style 5 wheels, new paint , all int/ext LED's clear corners, all vac leaks fixed, eonon 5166, ECS short shifter, LED ae's and fog lights (clear), all brakes, fixed trifecta, rear control arm camber repair, new throttle body, ccv delete, but it ended up as a huge vac leak, returned to new stock ccv, new injectors, cloned and replaced dme.
Reply With Quote
  #15  
Old 04-05-2016, 08:09 AM
Arawak420 Arawak420 is offline
Officially Welcomed to the 'Fest
 
Join Date: Aug 2015
Posts: 198
Mein Auto:
Mine is 23.5mpg average with 20" wheels. If i had the stock wheels average would be at least 25mpg.
Reply With Quote
  #16  
Old 04-08-2016, 01:22 PM
Vic_LeChic Vic_LeChic is offline
Registered User
Location: Spain
 
Join Date: Jan 2013
Posts: 53
Mein Auto: E92 330i Coupe N52B30
I check it every time I fill up. At last reading OBC showed 8.6L/100km, and real consumption at the pump was 8.4L, not far off.
__________________

If it feels good, go for it. If in doubt, there's no doubt.

my cars:
- BMW 330i Coupe E92 N52 (272 bhp) 2007
Montego blue - beige leather - piano black - M3 18" rims- Aero M sport front bumper - M3 rear spoiler - Sport seats

- SEAT Leon Cupra R mk1 (210 bhp) 2003
Ebony black - 18" rims - Brembo breaks - Recaro seats - Turbo charged twin intercooler
Reply With Quote
  #17  
Old 04-08-2016, 03:11 PM
rdl rdl is online now
Officially Welcomed to the 'Fest
Location: Ontario, Canada
 
Join Date: Jun 2010
Posts: 1,664
Mein Auto: 530i 2003
I check mine a regularly and find it quite accurate - less than 1/2 MPG difference.

In my most careful test I tracked over two fill-ups and ~800 miles. The OBC vs odometer distance / gasoline pumped agreed within less than 0.1% (but accidentally accurate, see below.) I've also checked odometer vs GPS trip log vs map routes over a few hundred miles. All agreed within 1%. So apparently in spite of the speedo inaccuracy, the odometer is pretty good, as is the DME's tracking of fuel consumption.

For the accidental part. Typical usable tire tread is ~6mm & E39 tire rolling radius is ~155mm => ~4% range or +/- 2%. So the odometer and therefore OBC MPG will have that error depending on tread wear. If you find your OBC MPG off by more than that consider the following.

The first car I ever owned with a fuel computer (back in the late '80s) was dead accurate when I bought the car - one trip a few thousand miles to the Pacific coast & return. A few years later it was off by as much 8% on some fill-ups. Thinking through how the ECU came up with a fuel consumption number I came to the conclusion that some or all injectors must have become clogged with deposits and the calculation of fuel actually injected vs injection signal (i.e. calculated) must be "off." I had the injectors cleaned and the fuel computer MPG was immediately accurate again. That was the day that I switched from searching out the cheapest (usually off brand) gasoline and made a point of buying brand name only; nowadays Top Tier certified. It's usually a 2 or 3 $ more per fill-up but keeps the injectors clean and the engine happier.
__________________
Regards
RDL

Last edited by rdl; 04-08-2016 at 03:18 PM. Reason: typo
Reply With Quote
Reply

See More Related BMW Stories


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 5 Series > E39 (1997 - 2003)
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 02:38 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
© 2001-2015 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms