101605-9292 ZEXEL INJECTION-PUMP ASSEMBLY Calibration Data 1016059292

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. The 3176 cruise control may use full engine power to return the truck to the cruise set speed if the engine was unable to maintain the set speed while climbing a hill. The cruise control should be turned off before cresting the top of a hill and light throttle used to regain vehicle speed on a downhill to minimize fuel consumption.If equipped with a Jake Brake exhaust brake, the engine should not exceed maximum braking rpm. Refer to "Jacobs Engine Brake" section of this manual.Saving Fuel On Hills
Rolling hills provide a great opportunity to reduce fuel consumption. Avoid downshifting on small hills. If a hill can be topped without downshifting, even if the engine lugs to the peak torque rpm (1100-1300), the truck should not be downshifted.On long grades that require one or more downshifts, let the 3176 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 minimized to improve fuel consumption.Cruising Speed
It's a simple fact that the faster a vehicle is driven, the more fuel it will consume. A few miles per hour (kilometers per hour) can make a significant difference in fuel economy.Increasing cruising speed from 55 to 65 mph (88 to 104 km/h) will increase fuel consumption of a typical class 8 truck approximately 1.0 mpg (0.4 km/L). A practice of driving faster to increase stop time makes those stops very expensive.Cruising is the most common operating condition for most trucks and therefore, provides the greatest opportunity to benefit from operation in the most fuel efficient rpm range of the engine. A significant improvement in fuel economy can be realized by operating the truck in a gear that will keep the engine between 1400 and 1600 rpm.The 3176 can be programmed to limit vehicle speed and encourage operation in the highest gear during a cruising condition for optimum fuel economy.Cruise Control (CC)
The 3176