Fuel Economy - What do you get out of a tank? (3rd gens only)

[AWD_Geoff]

Thanks guys.
I've been familiar with extractors for a long time. The way I like to look at them is that they are a versatile modification. If a car is driven gently (no faster than before) then a slight improvement in fuel economy can usually be expected. If the extra power and willingness to rev are taken advantage of, then fuel consumption won't improve (and probably get worse). Vlad your reply more or less confirms this.
I was interested to know if someone who has fitted them to a 3rd gen Magna has any objective data.
Macropod good calcs. I'm not necessarily expecting to recoup all my money but to put it another way I'm not interested in engine mods that lead to worse economy. Have you had extractors fitted to a Magna?

[macropod]

I have a set of HM headers on order ...