Maybe Unnatural (Archangel Academy) by Michael Griffo?
While this might seem like the typical love triangle, there's more going on below the surface at Archangel Academy. As in the human world, prejudices exist within the vampire world. We learn that while Nakano and Ronan are both vampires, they are two different breeds of vampires. Nakano's breed is of the more traditional variety; Ronan is a Water Vamp, a crossbreed between a vampire and a water-dwelling humanoid. The Water Vamps can walk in the sunlight, but they need to feed on blood and return to the sea of their birth once in awhile; Nakano's kind need to feed on blood on a regular basis, and while they can walk about in the daylight, they can only do so on the grounds of Archangel Academy, which right away informs the reader that there is something about the school, but what exactly it is is not revealed--at least not in this book. The Water Vamps are considered inferior among the vampire world. The conflict for the novel is set: vampire against vampire, and a seething jealousy of an ex toward his replacement.
Edit: Adding picture of beginning of Chapter 1 talking about pumping gas