We’re sure your friend will appreciate your efforts—and we’ve got your back!

You can open the gas tank on a 2015 Volkswagen Jetta by unlocking the car and gently pressing on the door of the gas tank. It should gently pop open, and then you’re good to go! Make sure that you’ve unlocked the doors, though—otherwise it won’t budge.

But before you head to the gas station, you might want to check with your friend and see what type of gas their Jetta needs. Some 2015 Volkswagen Jettas need premium fuel with a high octane rating while some can do fine with regular gas.

If your friend’s car needs premium gas, make sure to stick with that—otherwise, you might be thanking them with the gift of reduced performance and engine knocks. And not only is that uncool, but it also makes it highly unlikely they’ll ever loan you their car again!

MORE: Are Volkswagens expensive to maintain?