Fuel computer confusion by raistlin (Page 2 of 2)


User avatar
Bermudan 75
I have found that on motorway journey that the gauge rises a little when the car has cruise control activated.
Image

Posted 16 Feb 2013, 12:04 #21 


Jumper
Forgive me for belatedly catching up on this. I presume the computor makes no allowance for density of tank contents; therefore the only measurement could be volumetric. Would that be critical in a hot summer compared to a cold winter ? Or is the computor insensetive to such relatively small fluctuations, in which case merely negotiating a roundabout would have a large effect on fuel surface height?

Posted 22 Feb 2013, 19:19 #22 

User avatar
Duncan
You are right, the gauge simply measures the level. However the change in density would be accounted for by the engine management tweaking the injection amount, using the feedback from the lambda probes. Therefore what you would actually see is a minor variation in the MPG figures.
Image

Posted 23 Feb 2013, 09:35 #23 


Jumper
Thanks, never thought about this deeply before - tend to just take for granted!

Posted 23 Feb 2013, 12:12 #24 


Top