105489-0690 ZEXEL F 019 Z4E 991 BOSCH GOVERNOR f019z4e991 1054890690 223003941a

Downhill
When cresting a hill, the decision of whether to use power or not on the downside of the hill must be made. Best fuel economy results from using minimum power to get back to speed after climbing a grade. However, care must be taken not to allow the engine to overspeed. This engine should not exceed 2300 rpm.If equipped with an exhaust brake, the engine should not exceed maximum braking rpm. Refer to "Auxilliary Exhaust Brakes" section of this manual.Saving Fuel On Hills
Rolling hills provide a great opportunity to reduce fuel. Avoid downshifting on small hills. If a hill can be topped without downshifting, even if the engine lugs to the peak torque rpm (1100-1200), the truck should not be downshifted.On long grades that require one or more downshifts, let the engine lug back to the peak torque rpm. If road speed stabilizes with the engine running at or above peak torque rpm, remain in that gear. When going down hill, use gravity instead of engine power to regain vehicle speed.Long steep down grades should be anticipated. Vehicle speed should be reduced before cresting the top of a hill and proceeding down a long steep grade. The way to achieve maximum fuel efficiency, is to minimize the amount of braking that is used to maintain a safe vehicle speed.The engine's ability to hold the truck back increases with engine speed. A gear should be selected that runs the engine near the high engine rpm limit for long steep hills when braking is required.Speed reductions and future stops should be anticipated ahead of time to save fuel. Downshifts should be avoided and the amount of braking minimize