Generally speaking, for as long as DOHC engines have been around, they have always taken precedence over their cheaper, less complex single overhead camshaft siblings. On paper, the increased efficiency of DOHC engines are undeniable, proving time and time again to extract more juice from the same sized fruit. With the uprise in popularity of the technologically superior K series and continued prevalence of the well established B series, engines like the D series have become relics in today's world. What is regarded by many as a throwaway motor, is for others like myself, a viable option to modest performance at a low cost while achieving excellent fuel economy and stellar reliability.
