[Christ]

So lets do some math for you quickly then...

IF you get 1 more mippig out of this whole ordeal:

30 dollars total cost, divided by $2.50/gal for fuel = 12 gallons of fuel

12 gallons of fuel at 34.3 mippigs = 411.6 mippits (miles per tank)

12 gal @ 35.3 mippig = 423.6 mippits

423.6 - 411.6 = 12.0 more mippits than before.

411.6/12 = 34.3 tanks of fuel to reach payoff.

This doesn't take into account mileage spent going to gas stations specifically for fuel, etc...

Also - you can further add to the payoff point by saying something like: "My money stays in the bank for another 12 miles per tank, thereby getting "x" more interest."

It's snipping hairs, but so are many mods.