Having a debate with some people and was wondering what everyone's opinion on this was. How much more fuel would be used going wide open throttle versus if you were to go the same distance with out WOT, say the average speed limit of a highway?

 

I floor it everywhere and get about 10-12 mpg. I tried one driving normal and got over 15. Probably not the exact answer, but yours is hard to answer unless you try it.

 

The stock tuning sets the part throttle A/F ratio at 14.7:1. At WOT (PE mode) the PCM typically calculates an 11.8:1 target A/F ratio. You'll see a 25% increase in fuel consumption for that reason alone.

 

Thats what I was thinking closer to 25% more over the average usage. You go the same distance but in less time and working the engine harder to achieve the speed you are asking it for.