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Show Tips For The Y v ' Novice Automechanic ST- '"3 rSfc" apaa ' By Don B. Wilson, Member, SAE ' ? ' 1 Lugging Damages Engines Now that the popularity of manual transmissions is returning, re-turning, due likely to their better efficiency and yielding more miles per gallon than automatics, and now that many people are driving man-' man-' ual transmissions who have never driven them before, it becomes timely to mention the harmful effects of lugging engines. Lugging occurs when the engine is not turning over fast enough to develop enough power to accelerate the vehicle from the speed at which it is traveling. It is caused by failure to downshift down-shift to a low enough gear to pick up the load. Of course, the best miles-per-gallon are achieved only when the vehicle's transmission transmis-sion is in high gear, but often overlooked by the driver is the speed at which the car is traveling when in top gear. There is no pat miles-per-hour figure below which one should not travel in high, because be-cause of the different idle speeds of engines turned to meet emissions requirements, because of differences in axle ratios, and because of the size and power of engines. One can probably "coast along" in high gear with the engine turning over barely faster than idle speed, but when the need to pick up J0 speed arrives, the driver should drop down to a lower gear for that purpose and return re-turn to high gear when the engine is running fast enough in that gear to continue acceleration accel-eration without rumbling, shuddering, shaking, straining or knocking. Accelerating from too low a speed in too high a gear lugs the engine, and lugging damages dam-ages pistons, bends connecting connect-ing rods, hammers bearings and in short, "kills" an engine. en-gine. Lugging an engine will cause preemption of several weekertds if you do your own engine work, or will take your vacation money for its repair. So don't fail to downshift for any reason when your engine en-gine is at its low end and you need to pick un sncpH Automotive Parts & Accessories Association |