Computer MPG accuracy. - Civinfo
 
LinkBack Thread Tools
post #1 of 15 (permalink) Old 8th June 2010, 15:55 Thread Starter
 
Car: 2008 1.8 ES
Join Date: 25th May 2010
Location: Warwickshire & Valencia EUROPEANUNION
Posts: 115
Thanks: 5
Thanked 8 Times in 7 Posts
iTrader: (0)
MPG accuracy.

Hi all I have monitered my consumtion over three tankfulls against what the trip computer says.

Working out my MPG manualy and comparing this to the cars computer has shown that the computer is very optomistic.

Its varied over the three tankfulls by +3.2, +5.3, +4.7

Over the three tankfulls I'm actually getting 43.2mpg, but on setting B the car is showing 47.0mpg

Is this inaccuracy the norm?

Against ny sat nav the speedo also appears to over read by about 3mph across a wide range of speeds.

Regards all
spanish boy is offline  
Sponsored Links
Advertisement
 
post #2 of 15 (permalink) Old 8th June 2010, 16:16
Cockup Specialist
 
Relic's Avatar
 
Car: 2007 2.2 Type 'S' GT, Bronze
Join Date: 31st August 2009
Location: uk ENGLAND
Posts: 12,885
Thanks: 791
Thanked 1,690 Times in 1,437 Posts
iTrader: (0)
Well I checked the gearing on mine and done rpm vs speed.

The speed error was 1mph per 1000rpm in any gear.
As for the MPG some are apparently worse at guessing than others.
Check your tyre pressures and tyre size.

Mine is the 2.2 diesel...so yours will probably have a differnet rpm vs mph



Relic is offline  
post #3 of 15 (permalink) Old 8th June 2010, 16:58
Supporter
 
NoNumpty's Avatar
 
Car: 2008 2.2 i-CTDi ES NHB
Join Date: 20th May 2008
Location: Cheshire UK GB
Posts: 4,106
Thanks: 59
Thanked 347 Times in 331 Posts
iTrader: (0)
Speedo accuracy is here Is the speedo accurate? - Civinfo Wiki

wiki is your friend
NoNumpty is offline  
Thanks to NoNumpty from:
 
post #4 of 15 (permalink) Old 8th June 2010, 17:43
 
Join Date: 28th November 2008
Location: Bucks ENGLAND
Posts: 52
Thanks: 6
Thanked 2 Times in 2 Posts
iTrader: (0)
I've tracked 3 cars from 0-10k and it can vary either way by up to 10% on a tank but normally 3-4% generous.
Contayjen is offline  
Thanks to Contayjen from:
post #5 of 15 (permalink) Old 8th June 2010, 17:54
 
Car: 2006 Civic 2.2 CDTi EX
Join Date: 13th January 2010
Location: Chelmsford ENGLAND
Posts: 300
Thanks: 0
Thanked 15 Times in 15 Posts
iTrader: (0)
I don't know was constantley getting 44-47 MPG then the other day doing similar journey it shot up to 50 MPG and had an A next to the figure, never noticed this before?
Lex1970 is offline  
post #6 of 15 (permalink) Old 9th June 2010, 00:25
Quit yo Jibba Jabba
 
Griffiin's Avatar
 
Car: 2.2 Type-S GT Milano Red
Join Date: 22nd November 2008
Location: Lancashire GB
Posts: 177
Thanks: 4
Thanked 18 Times in 17 Posts
iTrader: (0)
I've found both my MPG and speedo reading to be pretty much perfect.
Griffiin is offline  
post #7 of 15 (permalink) Old 9th June 2010, 07:34
Administrator
 
Kremmen's Avatar
 
Join Date: 7th January 2007
Posts: 20,944
Thanks: 857
Thanked 1,708 Times in 1,431 Posts
iTrader: (0)
On both my Civics - whatever the computer says, take off 4-5 MPG and that is more like the true figure.

SpritMonitor (on the left currently showing 36.9) agrees with my spreadsheet but the trip comp continually puts my MPG in the low 40's.
Kremmen is offline  
Thanks to Kremmen from:
post #8 of 15 (permalink) Old 9th June 2010, 09:53 Thread Starter
** Thread starter **
 
Car: 2008 1.8 ES
Join Date: 25th May 2010
Location: Warwickshire & Valencia EUROPEANUNION
Posts: 115
Thanks: 5
Thanked 8 Times in 7 Posts
iTrader: (0)
Cheers Guys

Thanks for the answers

Regards all

John

I
spanish boy is offline  
post #9 of 15 (permalink) Old 9th June 2010, 11:11
Cockup Specialist
 
Relic's Avatar
 
Car: 2007 2.2 Type 'S' GT, Bronze
Join Date: 31st August 2009
Location: uk ENGLAND
Posts: 12,885
Thanks: 791
Thanked 1,690 Times in 1,437 Posts
iTrader: (0)
Quote:
Originally Posted by Griffiin View Post
I've found both my MPG and speedo reading to be pretty much perfect.
+1 perhaps its the type s GT 2.2 ??



Relic is offline  
post #10 of 15 (permalink) Old 9th June 2010, 11:22
 
jcw147's Avatar
 
Join Date: 24th April 2008
Location: 1/2 a mile further down the road than you ENGLAND
Posts: 882
Thanks: 36
Thanked 31 Times in 29 Posts
iTrader: (0)
Quote:
Originally Posted by Kremmen View Post
On both my Civics - whatever the computer says, take off 4-5 MPG and that is more like the true figure.
even the type R?..... oops its worse than i thought.
jcw147 is offline  
post #11 of 15 (permalink) Old 9th June 2010, 11:40
Supporter
 
Alanok's Avatar
 
Car: 2008 CTR, Alabaster Silver
Join Date: 30th March 2009
Location: Darlington, UK ENGLAND
Posts: 1,610
Thanks: 134
Thanked 240 Times in 219 Posts
iTrader: (10)
Send a message via MSN to Alanok
Quote:
Originally Posted by jcw147 View Post
even the type R?..... oops its worse than i thought.
Even on the R. I worked out my true mpg over a year and each time the trip computer was about 2-3 mpg more than actual. But my mpg is relatively high (36mpg) due to mostly motorway miles so it's possible the less your mpg figure is the less discrepancy the computer figure might have.
Alanok is offline  
Thanks to Alanok from:
post #12 of 15 (permalink) Old 9th June 2010, 11:55
Quit yo Jibba Jabba
 
Griffiin's Avatar
 
Car: 2.2 Type-S GT Milano Red
Join Date: 22nd November 2008
Location: Lancashire GB
Posts: 177
Thanks: 4
Thanked 18 Times in 17 Posts
iTrader: (0)
Quote:
Originally Posted by Relic View Post
+1 perhaps its the type s GT 2.2 ??
Interesting thought, I wonder if there are any differences in the way the MPG is calculated for the different engine types?
Griffiin is offline  
post #13 of 15 (permalink) Old 10th June 2010, 00:46
Supporter
 
kenP's Avatar
 
Car: 2014 1.6 i-Dtec SR, Red
Join Date: 12th January 2008
Location: Birmingham, UK GB
Posts: 853
Thanks: 0
Thanked 37 Times in 34 Posts
iTrader: (0)
On my 1.8 it used to be about 4-5 MPG to high on the trip, but on the Type R doing the same journeys it's within 1 MPG.
kenP is offline  
post #14 of 15 (permalink) Old 11th June 2010, 11:24
Supporter
 
Nick7's Avatar
 
Join Date: 10th August 2006
Location: Croatia
Posts: 763
Thanks: 0
Thanked 18 Times in 16 Posts
iTrader: (0)
On mine it's over-enthusiastic for approx 5-10%.
Nick7 is offline  
post #15 of 15 (permalink) Old 11th June 2010, 12:12
Supporter
 
NickS's Avatar
 
Car: 2009 2.2 EX 5 door
Join Date: 20th December 2008
Location: Cirencester, UK ENGLAND
Posts: 429
Thanks: 36
Thanked 30 Times in 29 Posts
iTrader: (0)
Mine's usually within about 2 to 3 mpg on a tankful. It claims, say, 47.7mpg, but truly more like 45.2mpg, based on brim to brim.

Appreciate the 1.8 may well be different, and I'd be surprised if they are recalibrated for different wheel and tyre combinations, that generally are all within about 5% of nominal diameter.
NickS is offline  
Reply

  Civinfo > 8th Generation Euro Honda Civic (2006 - 2011) > Electronics (8G)

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Civinfo forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Your User Name is the name that appears by all your posts on the forum, and so should not be your email address.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Speedo Speedometer Accuracy ChezzZ Electronics (8G) 10 29th March 2009 11:04
Speedo Speedo Accuracy Kremmen Electronics (8G) 5 7th March 2009 10:17
Speedo speedo accuracy (merged) Billybobbo Electronics (8G) 173 2nd November 2008 22:41
Speedo Odometer accuracy Foggy69 Electronics (8G) 10 27th September 2007 23:21
Computer Fuel meter accuracy gsyme Electronics (8G) 2 17th January 2007 00:14

Posting Rules  
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome