Confused about 'life time' mpg display

Thread Tools
 
Search this Thread
 
  #1  
Old 07-21-2008, 04:32 AM
motorups's Avatar
Enthusiast
Thread Starter
Join Date: Jul 2008
Posts: 1
Default Confused about 'life time' mpg display

I know I have a mpg display (instant if you will). I also have a mpg display that I had always thought was a 'vechile use lifetime mpg' display as in from the day I purchased the car up to today xx.x is the total mpg this vechile has gotten. Is that wrong...instead is it really a 'from this tank of gas' display to the next (thinking not)?

My ride is a 07 hihy and the only reason I ask is that my mpg jumped from 26.9 to 30.3 and all of this ONLY due to an about 150 mile ride last night after going to the dealer (still deciding if I will fall back to a gas 08 highlander or not...sorry). The sales guy has an 06 and hihy and he was saying that if you keep it in the slash marks (above blue and below the 0? mark) then you can get good mpg (yes I know read the manual...buried some place in the house at the moment but cannot locate it). Anyway, so I leave the dealer without the 08 gas limited highlander (white pearl...love that color) and as I drive I start to play around with staying in the green zone (slash marks) and yes (lord forbid...driving slower). On the way home did that very much (even a few coast up the slight hills when possible), maybe driving 5 to 10 miles per hour under speed limit if/when ok to do so (it was late at night and little traffic).

So, if the 30.3 mpg listed on my mpg is true for the life of the vechile then what I don't under stand is, since it has about 7,000 miles on it, how only a 150 mile trip can push that average up so quickly? I mean 7,000 miles at 26.9 one would think means you have to drive a heck of a lot more miles at a higher mpg level before that 26.9 would move higher to any degree.

Thus I'm dumb...
someone please educate me on what I do not understand about this mpg display (sorry no nav on my system, just those two dislays (one in speedo and other above a/c).

Try not to slam me too much on the thought about maybe trading in the hyhi...have two cars presently rx8 rotary (yes it loves gas) and the hihy so was thinking of droppping down to one still. Also have a burgman exec scooter that gets about 50 mpg that I would like to drive to work (5 miles) so that would become my 'gas saving' ride.

After last night I may have to rethink my driving habits and if I want to let her go. Afer all 26.9 is nice but 30.3 is starting match the mpg of some of those small cars yet our 07 hihy is a larger/nicer ride. Do though like the bells the 08 model offers (power rear hatch, sunroof, a bit wider for the two font seats)....yes I know, 20mpg average most likely on a gas 08 but that is what my scooter would be for.
 

Last edited by motorups; 07-21-2008 at 04:41 AM.
  #2  
Old 07-21-2008, 07:48 AM
Mr. Kite's Avatar
Ridiculously Active Enthusiast
Join Date: May 2006
Posts: 713
Default Re: Confused about 'life time' mpg display

I have the Navi on my 2007 HiHy, so I'm not totally sure how your FE displays work. However, you would not see that kind of MPG jump in your lifetime FE. The math just doesn't work. Maybe somebody else can answer this more definitively, but maybe the FE automatically resets after so many miles.

These vehicles can get decent fuel economy. There are some tips in this thread:
https://www.greenhybrid.com/discuss/...hlander-14849/
 
  #3  
Old 07-22-2008, 11:47 AM
Benton's Avatar
Active Enthusiast
Join Date: May 2008
Location: Portland, OR
Posts: 74
Default Re: Confused about 'life time' mpg display

Originally Posted by Mr. Kite
I have the Navi on my 2007 HiHy, so I'm not totally sure how your FE displays work. However, you would not see that kind of MPG jump in your lifetime FE. The math just doesn't work. Maybe somebody else can answer this more definitively, but maybe the FE automatically resets after so many miles.
We have an '08 RXh w/ nav. It has instantaneous MPG, the rolling 5-minute bar chart plus an MPG readout 'since last reset,' with a prominent 'RESET' button next to it (which we hit at refueling.)

To bump up from 26.9 and 7k miles to 30.3, I figure you'd have to coast for 885 miles. I'm guessing you somehow triggered the reset, maybe it's tied to a trip-odometer reset? Read the manual. Whatever you've been doing since the reset -- keep doing it. On one round-trip work commute, I got 35 MPG, so the highlander/RX's are capable of decent numbers, but you do have to work at it.

Break-in and warmer summer weather have made our last several tanks substantially better than the number in the sig.

Benton 22jul08
 
  #4  
Old 07-22-2008, 07:13 PM
MMooney's Avatar
Active Enthusiast
Join Date: Nov 2005
Posts: 196
Default Re: Confused about 'life time' mpg display

I can't prove this, but my other hybrid only holds a finite number of data points in it
s um, lifetime fuel average. If one never re-sets they get a moving average mpg reading that is based on this finite number of data points.

I'd be surprised if the higlander is set up to hold tens of thousands of miles of data.

MM
 
  #5  
Old 07-23-2008, 12:29 PM
Benton's Avatar
Active Enthusiast
Join Date: May 2008
Location: Portland, OR
Posts: 74
Default Re: Confused about 'life time' mpg display

Originally Posted by MMooney
I can't prove this, but my other hybrid only holds a finite number of data points in it
s um, lifetime fuel average. If one never re-sets they get a moving average mpg reading that is based on this finite number of data points.

I'd be surprised if the higlander is set up to hold tens of thousands of miles of data.
You're thinking it's remembering FE second-by-second or foot-by-foot and averaging 'em? I'd have assumed it was just tracking total miles (since reset) and total fuel (since reset) and dividing 'em... two numbers each bumped up each time the car decides it's burned another 1/100th gal of gas or rolled a couple more feet. OTOH, if it really does switch to a rolling average at some point I guess it is tracking FE in some units.

I'll stick by what I said, tho', recalculated--for the OP's FE to jump up from 26.9 to 30.3, the data packets that
fell off the calc had him burning 25 gallons of gas w/o going anywhere.

Benton 23jul08
 
  #6  
Old 07-23-2008, 03:39 PM
MMooney's Avatar
Active Enthusiast
Join Date: Nov 2005
Posts: 196
Default Re: Confused about 'life time' mpg display

Originally Posted by Benton
You're thinking it's remembering FE second-by-second or foot-by-foot and averaging 'em? I'd have assumed it was just tracking total miles (since reset) and total fuel (since reset) and dividing 'em... two numbers each bumped up each time the car decides it's burned another 1/100th gal of gas or rolled a couple more feet. OTOH, if it really does switch to a rolling average at some point I guess it is tracking FE in some units.

I'll stick by what I said, tho', recalculated--for the OP's FE to jump up from 26.9 to 30.3, the data packets that
fell off the calc had him burning 25 gallons of gas w/o going anywhere.

Benton 23jul08
The consensus for the ave on the FEH is 2000 data points, one every minute, so 33 1/2 half hours of 'running time'.

I agree with you, unless there was an accidental re-set, unseen by the driver, the average numbers are wildly skewed. If there had been a re set, and there were only, say 20 data points, it doesn't take much to cause a big swing.

MM
 
Related Topics
Thread
Topic Starter
Forum
Replies
Last Post
nass_a_b
Toyota Camry Hybrid
7
02-24-2013 03:19 PM
jb3710
HCH II-Specific Discussions
6
01-02-2009 05:16 PM
exbauer
Ford Escape Hybrid
2
11-20-2008 09:00 AM
GreenAndBlue
Fuel Economy & Emissions
11
09-23-2007 11:10 AM
kenny
Honda Civic Hybrid
11
01-13-2006 02:30 AM



Quick Reply: Confused about 'life time' mpg display


Contact Us -

  • Manage Preferences
  • Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Your Privacy Choices -

    When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

    © 2024 MH Sub I, LLC dba Internet Brands


    All times are GMT -7. The time now is 10:43 PM.