hey all,

mine is the same, doesnt seem to drink anymore with aircon on, i always thaught it must have been the underdrives but now i think i like scaffy's idea. i get just under 600km on the highway and have no idea about round town, dont think i realy want to know with the price of fuel these days.

The A/C load is low and it does get lower as you go because once it's achieved the desired temp it doesn't have to work much to maintain it.
Cars with centrifugal blowers will generally get better fuel economy than other types because at cruise the light positive pressure from the blower actually increases VE because the power used to drive the blower is very low.

This happens for the I6's as well - CC and non CC cars. IIRC the relay involved sits under the coolant recovery bottle.

Yes we did know this but of course Wide open A/C cutout does not help with fuel economy because it occurs at WOT only.

Interesting read guys

Timmeh - my opinion on better economy on tuned cars is rather simple - Ford, (like most car manufacturers) factory tune cars rich to avoid leaning out and detonating - especially with our mixed climates here, you would rather burn more fuel than cause damage to your car...something to ensure less warranty jobs in the future too.

For instance whenever commodores got sequential injection, they boasted fantastic economy but I have heard of many failures when looking longevity - whether this is a sequential tuning concern or just overall lean-ness of the tune I am unsure...just going on what I have heard in and around the traps.

In going from one extreme scenario to another, I do believe an aftermarket tuned falcon to suit engine mods can obviously be done safely and more fuel efficiently however the power is in the hands of the tuner.

......