Principio Diesel is a diesel repair and performance shop in McHenry, IL. Our team of diesel repair professionals have over 20 years of experience, so our customers know that they are receiving honest, quality repairs. While our main focus is diesel repairs, we also offer diesel performance and accessories to fully outfit your vehicle. We realize diesel repairs and maintenance can get overly expensive, so we're committed to having our repairs be at a reasonable price. Contact us today to schedule a repair.