Why does chipping a diesel increase MPG as apposed to chipping a petrol which decreases it ? :confused:

It doesn't necessarily work like that in either case!

Rob.

percentage of time the throttle is open wide... if you achieve the same speed a chipped car will be more economical... but as we all hoon it then it isnt.

chipping is more economical, in both cases, *if* you are the same with the throttle.

But the same throttle position would be putting in more fuel wouldn't it ?

But the same throttle position would be putting in more fuel wouldn't it ?

Yes , but on a chipped engine you wouldn't need to depress the throttle as much to maintain the same speed.

hehe - I wish my mpg went down when chipped.... I estimate around a 10% drop is realistic for me on average, but I did get a couple of good tankfuls when chipped, still running on steels though - 17s have about as negative an effect on mpg as chipping did, so now I average around 40-43mpg at best I reckon. :(

I think the idea is that the increased torque reduces need for downchanging to maintain a steady speed (e'g when going uphill) therfore using less fuel....

certainly didnt improve fuel economy in my case though! :(

Chipping any car usually increases it efficiency...

I think most petrol and TD engines see an increase...

Depending on how they are driven of course!!

Ta

Dazz

Think mine has increased mpg when driving normally. But when you floor it all changes. Did a test on a motorway near my home. In 6th I accelerated from 80mph to *10mph. The trip was showing 22mpg :eek:

Think mine has increased mpg when driving normally. But when you floor it all changes. Did a test on a motorway near my home. In 6th I accelerated from 80mph to *10mph. The trip was showing 22mpg :eek:

surely thats decelerated

surely thats decelerated