How much fuel does WOT burn? You might WOT for what, 5 seconds, then drive sanely the rest of the time. Might take 0.1mpg off the entire tank.
Heck, you could probably even it out if you decide to coast for a few stops, instead of braking, so as to make up for that.
WOT for 5 seconds will reduce your consumption by a lot more than .1mpg. Waste is waste. If a guy drives a V8 and drives at WOT just for fun, the complaining about the cost of fuel is a bit disingenuous.