The direct line to al-Qaeda

I have been running an unscientific experiment.

Two weeks ago, I filled my car's tank with gas. Total cost: $36. Two weeks ago, Steve filled the truck's tank with gas. Total cost: $80.

Today, I have 3/4 of a tank left. Steve has half a tank left.

Now, this is not really a fair experiment. My car gets much more use than Steve's truck. He works across the street, but I drive Michael across town to school every day. I estimate that the car gets ten times as much use as the truck, because we usually take the truck for groceries once a week, and the grocery store is on the way to Michael's school. I am going to be extra generous and estimate up, because he DOES use the truck to go to the dump about once a month. So let's say that the car gets five times as much use as the truck.

That means that I've spent $9 to drive five times as far as Steve's truck has gone on $40 in gas. I'm not, like, a math teacher at an elementary school or anything, but I'm guessing that that's a significant difference. If only I could find a sheik or mullah or someone to explain it to me.