Volvo Community Forum. The Forums of the Volvo Owners Club

Forum Rules Volvo Owners Club About VOC Volvo Gallery Links Volvo History Volvo Press
Go Back   Volvo Owners Club Forum > "Technical Topics" > V40/XC '12>17 General > V40/XC '12> Articles

Notices

Information
  • VOC Members: There is no login facility using your VOC membership number or the details from page 3 of the club magazine. You need to register in the normal way
  • AOL Customers: Make sure you check the 'Remember me' check box otherwise the AOL system may log you out during the session. This is a known issue with AOL.
  • AOL, Yahoo and Plus.net users. Forum owners such as us are finding that AOL, Yahoo and Plus.net are blocking a lot of email generated from forums. This may mean your registration activation and other emails will not get to you, or they may appear in your spam mailbox

Thread Informations

Fuel consumption

Views : 402

Replies : 3

Users Viewing This Thread :  

Reply
 
Thread Tools Display Modes
Old Oct 29th, 2024, 19:05   #1
Mal58
New Member
 

Last Online: Oct 30th, 2024 16:27
Join Date: Oct 2024
Location: Talsarnau
Default Fuel consumption

I use a display theme which shows average fuel consumption in the left hand lower display, I also cross check by resetting the trip every time I refuel and dividing miles by how many litres I put in.
I'm getting about a 12% discrepancy between the average fuel consumption and the miles/litres crosscheck, actual mpg is 12% lower.

This is on a low mileage V40 T3, anyone else having issues with fuel consumption not being reflected accurately?
Mal58 is offline   Reply With Quote
Old Oct 30th, 2024, 10:40   #2
RS3100
Member
 

Last Online: Today 19:03
Join Date: May 2019
Location: Europe
Default

As the speedometer over-reads on nearly all vehicles to comply with legislation, the figures shown in in-car displays are rarely accurate. A better method is to brim the tank on every refill, note the volume of fuel filled and mileage travelled. Over time this should give you a much more accurate indication.
RS3100 is offline   Reply With Quote
Old Oct 30th, 2024, 16:26   #3
Mal58
New Member
 

Last Online: Oct 30th, 2024 16:27
Join Date: Oct 2024
Location: Talsarnau
Default

I'm already brimming the tank, have been for years as I like to know if something is potentially wrong (Also, fuel is a significant cost and sorting out tuning issues normally pays for itself over time).

I previously had a 2.2D Mazda 6 which showed virtually identical average mpg to my brimming the tank calculations.
Average MPG is calculated using fuel supplied to the injectors which is extremely precise, the only other metric involved is mileage which is according to GPS is reading 3.33% over (Speedo shows 62 when GPS shows 60).

The 12% discrepancy is over 1800 miles and is fairly consistent per tank.
Mal58 is offline   Reply With Quote
Old Oct 30th, 2024, 18:18   #4
RS3100
Member
 

Last Online: Today 19:03
Join Date: May 2019
Location: Europe
Default

Quote:
Originally Posted by Mal58 View Post
Average MPG is calculated using fuel supplied to the injectors which is extremely precise, the only other metric involved is mileage which is according to GPS is reading 3.33% over (Speedo shows 62 when GPS shows 60).
What is your source for that information please? I'm not saying you're wrong, but according to VIDA no such parameter or data related to fuel supplied to the injectors is either generated by the ECM or supplied to the DIM, at least on VEA petrol engined cars.

The DIM receives distance travelled information from the BCM according to the number of wheel rotations counted and the programmed tyre circumference. The latter can differ substantially from the actual rolling circumference. On my car with 205/55R16 tyres the rolling circumference is factory programmed as 1935mm, whereas the actual rolling circumference of my tyres as measured varies from 1985mm for the OEM tyres to 2000mm for the all season tyres that I currently have on the car. Both sets of tyres are the same nominal size.

Fuel level and hence consumption is calculated by the DIM according to the tank sensor voltage, which varies according to the volume of fuel left in the tank.

Average fuel consumption is apparently calculated from the last trip counter reset according to calculated distance driven and calculated fuel consumption.

Last edited by RS3100; Oct 30th, 2024 at 18:21.
RS3100 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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 Off

Forum Jump


All times are GMT +1. The time now is 21:22.


Powered by vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.