The chilton's is almost like the helm's but with some good info missing. The Hayne's has way more pictures on how to do things and has good tests for alot of the sensors which Chilton's doesn't have. I have both. Hayne's will illustrate steps with pictures. Chilton's just gives a step by step instruction with 1 assembly drawing and you have to draw the pictures in your mind. Chilton's will go into discussion about emissions controls and how they work, etc.