E90Post
 


Alpine HID
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > NA Engine (non-turbo) / Drivetrain / Exhaust Modifications > interesting observation about mpg's



Reply
 
Thread Tools Search this Thread
      02-12-2009, 02:38 PM   #1
tna3
Private
 
Drives: 335i SP MT
Join Date: Nov 2008
Location: MA

Posts: 67
iTrader: (0)

interesting observation about mpg's

I took my 07 328 MT to the dealer the other day and they gave me a loaner 328i with the auto tranny for 2 days. Driving the same route back and fourth I noticed the loaner got about 21.8 mpg's compared to the usual 23.5 that I get on mine.

Haven't driven the auto before but one thing I noticed right away is that when I let off the gas while cruising above 20 miles/hour, the mpg needle never goes all the way to the left. It hovered around 50.

On my M/T if I let off the gas and the car is in the highest gear at the same speed the needle basically indicates infinite mpg's - meaning that no or little gas is injected as the inertia of the vehicle is cranking the pistons.

Does this make any sense? I guess it's better not to put the car in to neutral when cruising slowly to a stop. I would have expected the auto tranny to behave the same way.
tna3 is offline  
0
Reply With Quote
      02-12-2009, 03:14 PM   #2
ptx1
Private
 
ptx1's Avatar
 
Drives: 2008 328i Titanium Silver
Join Date: Jul 2008
Location: NOR_CAL_BAY_AREA

Posts: 71
iTrader: (0)

It makes sense. I have 328i auto, but mine goes to virtually inifity when I let off the gas above 20 mph. I think the computer that suppose to "adapt" to your driving habits in your loner car just takes awhile to "adapt" (wish they would tell us what it actually does).
ptx1 is offline   United_States
0
Reply With Quote
      02-17-2009, 10:15 PM   #3
cbetlyon
Second Lieutenant
 
cbetlyon's Avatar
 
Drives: 07 328xi Jet Black/Black
Join Date: Oct 2008
Location: Winston-Salem, NC

Posts: 264
iTrader: (1)

Send a message via AIM to cbetlyon Send a message via Skype™ to cbetlyon
i wish i got 20. in my 328xi with auto tranny im getting 17.5 mpg
cbetlyon is offline   United_States
0
Reply With Quote
      02-18-2009, 04:09 PM   #4
Zanza
Private First Class
 
Zanza's Avatar
 
Drives: E90 325i Arctic Metallic
Join Date: Jun 2008
Location: FL

Posts: 112
iTrader: (0)

My car's needle never reaches the mark all the way on the left, even when its on a incredibly steep decline and the pedal isn't pushed. It usually stays around 50 mpg. If it is coasting down a hill at the same speed in Neutral it will touch the mark all the way on the left. I do not see how gently putting it in neutral while cruising would hurt the car anymore than regular shifting, however, I am no expert by any means so let me know if I am wrong.
__________________
gators
Zanza is offline  
0
Reply With Quote
      02-19-2009, 05:11 PM   #5
Kevin G
Private
 
Drives: '05 M3
Join Date: Oct 2008
Location: San Ramon, CA

Posts: 75
iTrader: (2)

Quote:
Originally Posted by cbetlyon View Post
i wish i got 20. in my 328xi with auto tranny im getting 17.5 mpg
Me too! I can barely get it over 17 actually. But I do a bit of city driving. And I always drive in "manual" mode.
__________________
E46 '05 M3 | TiAg/Imola | 6MT | ZCP | NAV | HK
Kevin G is offline   United_States
0
Reply With Quote
      02-19-2009, 05:46 PM   #6
Andrew@ET
Brigadier General
 
Drives: Red thing
Join Date: May 2007
Location: Earth

Posts: 4,041
iTrader: (9)

6mt 328 i floor it about every 5 sec i get 21.8 mpg

highway at 70 i get 33-35
Andrew@ET is offline  
0
Reply With Quote
      02-19-2009, 10:39 PM   #7
pittyinSC
Drives Smart
 
pittyinSC's Avatar
 
Drives: 2008 BMW M5 SG/Blk 6spd
Join Date: Jan 2007
Location: Charleston, SC

Posts: 2,386
iTrader: (2)

Garage List
2006 330i  [0.00]
Send a message via AIM to pittyinSC
In city I get like 17mpg haha well that is my average at the moment, but on highway I get like 30-36
__________________

08 BMW ///M5 Space Gray/Black 6 speed
Engine: RPi GTS exhaust, RPi Scoops, Carbon Filter Delete
Exterior: Glossy Black Kidneys, LUX V3, OEM LED License Plate light, Bruce License Plate Adapter
pittyinSC is offline   United_States
0
Reply With Quote
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 Off
Forum Jump


All times are GMT -5. The time now is 04:19 AM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST