Oh, the choices you encounter at the rental car counter!

        Would you like to upgrade? (Why, yes, that convertible looks lovely!)

        Would you like a GPS? (Nope, I’ve got a smartphone, thanks.)

        Would you like insurance? (No, thanks. My policy covers it!)

        Would you like to pre-pay rental car gas? (Ummm … )

That last one always stumps me — and I bet it’s the same for you too. Here are 3 common fuel options and the pros and cons of each.

1. Prepay for a full tank of gas

With this option, you decide in advance that you’ll return the car as close to empty as you safely can.

Pros

  • Convenience: Have you ever noticed how difficult it is to find a gas station near the airport? If you’re like me, you probably didn’t leave enough time for a game of hide-and-seek, so this is a nice perk.
  • Good price: The prepay option typically rewards you with a very competitive fuel price, but it can vary.

Cons

  • Not using your gas: So you thought you’d be driving all over town. Then you found out your client was chauffeuring or that the hotel had a convenient, free shuttle that saved you from having to navigate unknown streets. Or maybe you used an entire tank sightseeing, but you had to refill mid-trip and weren’t sure how much to put in so you overbought. Too bad, you’ve still paid for an entire tank, even if you haven’t used it all.
  • Driving around near empty: In an effort to squeeze every dime out of this perk, it can be tempting to run the tank lower than you should. But running out of gas is not only extremely dangerous — you’re also likely to miss your flight if you have to wait for a tow.
Check out:  How to Be a Luckier Driver in the Year of the Rabbit

2. Return your car full

Pros

  • Cost savings: If you’re in a city where you’re mostly parking your car at the hotel, you’re unlikely to use much gas, so prepaying for an entire tank can really cost you.

Cons

  • Paying a premium if you neglect to fill it up: Car rental agencies typically charge a hefty surcharge for filling your tank if you return the car less than full and didn’t opt for prepayment. Also, “full” means really, really full to most car rental agencies. Find a station right near the return so you don’t use an eighth (or so) of a tank driving from your convenient suburban station to the airport. Tip: Save your receipt so you can show them exactly where you filled up.
  • You have to find a station: Fuel pumps near the airport are frequently hard to access and you can waste precious minutes trying to find them. Tip: Ask the counter staff where to refuel when you get the car.

3. Allow them to refuel

Pro

  • No hassle: Seriously, no hassle. Just drive up and head off.

Con

  • You get what you pay for: And chances are good you’re paying a lot for “no hassle.”

The bottom line is each travel situation may have a different best choice for when to pre-pay rental car gas or when to fill it up yourself.

And if you want to know whether it’s cheaper to fuel up today or tomorrow, check out Fuelcaster® — the Gas Price Predictor.

Travel hacks | Getting there

about Cathie

Cathie Ericson writes about personal finance, real estate, health, lifestyle, and business topics. When she's not writing she loves to read, hike, and run. Find her @CathieEricson.