CNN.com Article - Guy fills Prius for $43

If you're regularly driving past gas stations, it doesn't cost extra to pull in and put in some gas. Plus, if you always keep it less than half full (rather than always topping off), you're saving probably 40 pounds or more in weight that has to be accelerated and stopped (at a little more than 8 pounds/gallon).

 

according to the wife if she just puts in $20 in at a time she plan her trips better.

 

Takes more gas and more time. Starting and stopping (see below) will do that. It adds up. And I know precious few people who go to the handiest station. So many actually drive to the cheapest one to fill up.

When the Prius is shut down and restarted, it runs the ICE even if it is already warm and is not needed for traction. And if you don't stop at the gas station, that's one more stop/start to move the full 3,000 pounds of vehicle - with or without the 40 pounds of gasoline.

Yeah, I'm picking at nits... still seems like a waste to hit the gas station more than you need to. Also pollutes more just because of the raw benzene that is released every time the pump is used.

 

If that's the case, then I'm all for it! She should try an EV some time. She'll get REALLY efficient at trip planning.