M P G

[granby]

Not really bothered about the MPG on my car as it's not the reason i bought it but today i was quite amazed at the mileage i got

Went down to Cardiff to pick some tyres up and i decided i'll do no more that 70mph, a bit boring i know but i thought i'd stick with it and i managed to get 31.41mpg which i thought was good

On the trip back i decided to speed up a bit and was averaging around 80-85mph and i got 33.51mpg

So why did i get better mileage when i was going faster

[leebo77]

Found the same in all of my cars. Must be the ideal 'cruising' speed for the engine....

....honestly officer.

[Kit]

Yeah they are very economical, but as soon as you floor it you can actually see the fuel gauge going down.

[scoobytibs]

you must of got 60 mpg on that autobahn then lol

[emoe]

Found the same in all of my cars. Must be the ideal 'cruising' speed for the engine....

....honestly officer.

It comes down to the fact that at that speed, the car is on teh cusp of being able to roll againt the wind resistance without needing more input from your right foot.

So if you go a little slower, you need to press down a bit more to keep going, therefore the maf sensor reads changes in air volume, the throttle pos sensor notices changes and the ECU dumps fuel in to help.

I notice it on my Apexi, i have airflow and injector duty showing and when cruising at 60 it shows something like 8.-% duty and 3400cfm, but at 85 it shows 5.-% duty and 3600cfm (or so)

so it shows that even though its pulling a bit more air in at higher revs cruising, it needs less throttle input to keep stable so the fuel isnt needed so much!

There ill take off my Mythbusters hat now!!

[scoobytibs]

thats just wot i was going to say emoe

[granby]

It comes down to the fact that at that speed, the car is on teh cusp of being able to roll againt the wind resistance without needing more input from your right foot.

So if you go a little slower, you need to press down a bit more to keep going, therefore the maf sensor reads changes in air volume, the throttle pos sensor notices changes and the ECU dumps fuel in to help.

I notice it on my Apexi, i have airflow and injector duty showing and when cruising at 60 it shows something like 8.-% duty and 3400cfm, but at 85 it shows 5.-% duty and 3600cfm (or so)

so it shows that even though its pulling a bit more air in at higher revs cruising, it needs less throttle input to keep stable so the fuel isnt needed so much!

There ill take off my Mythbusters hat now!!

Cheers for that

[scoobytibs]

thats ok boss anything else you want answered just let me know (and i will ask emoe) lol