Zip and Beep. Mighty Truck (Level 1): Chris Barton

Clarence was just a muddy pickup. One day there was a big storm, and lightning zapped the car wash. Now Clarence has a secret: Water turns him into MIGHTY TRUCK!
Mighty Truck is super strong, super fast . . . and a super fun babysitter!
When Hattie's bulldozer cousins Zip and Beep visit Axleburg, Clarence offers to watch them on his day off. Zip and Beep play tag, kick the can, and jump jumper cables-but no matter how fast they zoom, Zip and Beep just don't run out of gas! How can Clarence keep up with these wheely energetic youngsters?
Sounds like a job for Mighty Truck!
Mighty Truck: Zip and Beep is a Level One I Can Read book, which means it's perfect for children learning to sound out words and sentences.