Once the kids were buckled into their seats and the cabin door was closed, Nour started the rover. It ran on an internal combustion engine burning methane, a fuel that was made on Mars from the water and atmospheric gases available. Most of the kids had never been in a rover, and the vibration of this engine was unlike anything they had experienced.
From Water: Generation Mars, Book Three. Available now at https://www.amazon.com/Water-Generation-Mars-Book-Three/dp/1733731067
Image: public domain (https://commons.wikimedia.org/wiki/File:Carbon_County_High_School_Bus_by_Studebaker,_Utah_c_1912.jpg) with a few added tweaks