MAINTENANCE of the automobile engine of to-day is little more than a process of periodic adjustment and replacement, necessitated by wear in component parts. Accordingly any systematic study of the factors causing or influencing such wear will be followed with interest by users and manufacturers alike. In recent years, the Research Committee of the Institution of Automobile Engineers, Watergate House, York Buildings, Adelphi, W.C.2, has undertaken the investigation of wear occurring in various parts subjected to the trying temperature conditions existing in and about the combustion zone. This work has been particularly fruitful. Last year the Committee issued a report on “Cylinder Wear” which attracted considerable attention, and now it has published the results of its work on “Valve Seat Wear”.