Ive been told that you can run logs whilst driving to see how the engines performing, is this correct?

If so i would like to do this as i think my mpg is poor.

Question is though, how would i do this?

and what information will it give me?

Seems like an idea if you can not remember how much fuel you put in and how long or short your journeys are in which weather.

or

if you need to show the MPG to others.

(For my own shake i just use my digital camera and my memory and monitor my fuel usage.

i know how i drive and the oil temperature, 5 miles till 50 degrees celcius just now and 9 miles to get to 80 =degrres celcius,

and my speed.

easy to know when 50 mpgplus is possible ,

and when it was only getting 22 mpg, it was me driving)

Short journeys where the car has just warmed up before stopping will not give you the best economy.

A journey where you are stopped in traffic and crawling in traffic is not how many miles you did, but how long was the engine running.

How fast do you drive on a 60 limit or 70 limit road would need to go in the log.

So how many miles per gallon do you think you get, and with what car/engine?

Is this in or out of Edinburgh?

*If going only on a 10 miles trip in Edinburgh but using 1.5 gallons because it takes an hour almost,

that can not really be counted as a poor MPG,

i get nowhere fast in Edinburgh unless on the By-pass,

then my MPG is really poor.

george

Thank you for your in depth reply,

im mostly out of edinburgh on the out skirts, i average 40mpg with a standard car mechanically with a new maf sensor.

i wanted to run logs to see if the air flow was ok so id know if the egr was cleanish or not!