The great fuel consumption poll

[darbs]

i think let it ride with what you've got. people can point out certain deficiencies and we can take them into consideration. personally, i say thx for making the effort. i voted with what i usually get. makes most sense to me. others may wish to vote best or worst. let's face it though, we're never going to get gallup or MORI standards on a forum, so just make the best of it.

[Jonluke]

Originally Posted by jimbg

Jonluke,
To be honest, there are so many permutations of models and transmission it probably is a major task.

Do you really want to do it?

Well if members feel that this thread is a total waste of time then I would be open to doing it, but it would take some time... I kind of like seeing it all in one thread even if its more vague then some would like - more accurate data can be added in the comments as we go...

[jimbg]

Originally Posted by Jonluke

Well if members feel that this thread is a total waste of time then I would be open to doing it, but it would take some time... I kind of like seeing it all in one thread even if its more vague then some would like - more accurate data can be added in the comments as we go...

Well how about adding the D3 AWD and then I can post!!

[wimorrison]

Originally Posted by jimbg

Well how about adding the D3 AWD and then I can post!!

Problem is that you cannot edit a poll once it has started.

What I want to know is how people are getting into the 33-45 mpg with a D5 - jealousy or what.

[darbs]

Originally Posted by wimorrison

Problem is that you cannot edit a poll once it has started.

What I want to know is how people are getting into the 33-45 mpg with a D5 - jealousy or what.

i drove through thetford forest today fully laden at about 47 with cruise on and the computer was showing a pretty constant 45-48mpg. if i made that journey every day, i'd probably get over 33 easily. as it is, with loads of city driving, i scrape into the 25+ category.

[volvorocks]

Posted this elsewhere as well:

Just done a circa 250 mile round trip through Cheshire - Stafford - Leeds mixed driving, bit of urban traffic, some 50mph motorway speed limited,some heavy full on acceleration from time to time,generally keeping to 70/74 mph on the speedo and some idling at an average speed of (on the trip) of 51mph and achieved 40mpg.On and off cruise

Over 1.5k as a guesstimate I have averaged 32mpg (I would say 50/50 urban/ motorway)

Regards

[wimorrison]

It has occurred to me that the up to 10% variation that speedometer is allowed to have will also affect the fuel consumption figures as the distance recorded on the odometer is fed by the same algorithm that feeds the speedometer.

This means that the distance could be inaccurate by up to 10% also, which then feeds through to the mpg You also need to allow for the tyre wear - I have just fitted new tyres that have a depth of 9mm - if I replace them when the tyre depth is 3mm then the circumference is 37mm (1.5") less which will have an affect on the distance traveled and used by the ECU.

This would also explain the variations that people see (me included) between the brim to brim fuel consumption and the indicated consumption.

[844PHW]

Originally Posted by wimorrison

It has occurred to me that the up to 10% variation that speedometer is allowed to have will also affect the fuel consumption figures as the distance recorded on the odometer is fed by the same algorithm that feeds the speedometer.

This means that the distance could be inaccurate by up to 10% also, which then feeds through to the mpg You also need to allow for the tyre wear - I have just fitted new tyres that have a depth of 9mm - if I replace them when the tyre depth is 3mm then the circumference is 37mm (1.5") less which will have an affect on the distance traveled and used by the ECU.

This would also explain the variations that people see (me included) between the brim to brim fuel consumption and the indicated consumption.

Someone needs to check out these issues in an accurate manner. I might have a go over Easter.

[jimbg]

Originally Posted by 844PHW

Someone needs to check out these issues in an accurate manner. I might have a go over Easter.

I had a long debate on another thread about mpg, the fuel consumed figure will be very accurate but the distance measurement is the area of possible concern.

But, does the speedo over-reading actually correlate to any error in the distance traveled? Or is the speedo over-reading independent of the distance run?

Need to take a GPS on a very straight road on cruise control to compare speed.

Not sure how to check distance accuracy?

[volvorocks]

Originally Posted by wimorrison

It has occurred to me that the up to 10% variation that speedometer is allowed to have will also affect the fuel consumption figures as the distance recorded on the odometer is fed by the same algorithm that feeds the speedometer.

This means that the distance could be inaccurate by up to 10% also, which then feeds through to the mpg

This would also explain the variations that people see (me included) between the brim to brim fuel consumption and the indicated consumption.

I have posted about this a few times before in here!