0303395 JOHNSON SCREW

Driver Techniques
The manner in which a vehicle is operated can have a dramatic effect on fuel consumption. Operators can maximize fuel economy and engine life by practicing the techniques of using minimum power and low engine rpm. The 3176 can be programmed to ensure that the engine and vehicle are operated within specific limits for maximum fuel economy. (Refer to topic "Customer Specified Parameters" in this publication for information.)The "gear fast/run slow" concept is new to many in the trucking industry, but not to Caterpillar. Caterpillar engines are designed to operate at lower engine rpm (speed) and have demonstrated excellent fuel savings and longer service life when operated in this manner.Starting Out
Before start up, check all engine fluid levels, belts, hoses, and wiring harnesses. Simple checks can catch problems early and prevent costly highway breakdowns.Before engaging the starter, always depress the clutch to remove the transmission drag from the engine. In cold weather, depressing the clutch can make the difference between starting and not starting the engine.Below 40°F 5°C), the 3176 automatically idles at 1000 rpm. The vehicle inspection will usually provide sufficient time for the engine to warm-up enough for the 3176 to reduce engine rpm to the programmed low idle rpm.In warm weather, depressing the clutch produces faster starts and reduces battery drain. After starting, check for engine oil pressure and let the engine idle at less than 1000 rpm or at programmed low idle.Caterpillar truck engines do not require long warm-up times that waste fuel. The time it takes to conduct a walk-around-inspection of the vehicle and engine is usually sufficient warm-up time.A load can be applied to the engine after normal oil pressure is reached and the water temperature gauge begins to rise.To get the vehicle in motion, use a gear that will result in a smooth, easy start without increasing engine speed above low idle or slipping the clutch. Engage the clutch smoothly to avoid jerky, interrupted starts and stops which put stress on the drive train and waste fuel.Keep engine rpm (speed) at a minimum. Use just enough rpm to pick up the next gear. This technique saves fuel and will not harm the engine.Progressive Shifting
Drive Line efficiency is best in the low to mid rpm range (1100 - 1600 rpm) of the engine due to reduced frictional losses of the engine, transmission and rear axles. When accelerating under normal level road conditions, the engine should be operated in this most efficient rpm range by using only enough power to pick up the next higher gear. This technique of upshifting at the lowest possible rpm is called "progressive shifting."Progressive shifting also reduces the time to accelerate to the desired vehicle speed. Top gear is reached sooner because engine rpm does not have to fall off as far to synchronize the gears of the transmission. The key to progressive shifting is to use minimum rpm, minimum power and upshift early while accelerating the truck.The 3176 can be programmed to limit engine acceleration above pre-programmed engine rpm settings. This feature encourages the operator to practice progressive shifting techniques. Refer to"Driving Techniques for Maximum Fuel Economy," Form LEDT5092 for more information.Vehicle Speed Limiting (VSL)
The 3176 engine can be programmed to limit vehicle speed. When programmed, the 3176 system will not allow the engine to develop power after the vehicle speed limit is reached. Vehicle speed is one of themost critical ingredients of fuel economy. Extra speed is very expensive, and usually does not shorten trip time by more than a few minutes.Climbing Grades
Minimize the number of downshifts. Vehicle speed (momentum) is always lost between downshifts. Therefore, unnecessary downshifts waste a portion of that fuel consumed to maintain vehicle speed in the previous gear. Your Caterpillar engine has a very broad usable speed range and excellent torque rise that will provide exceptional hill climbing capability.When climbing a hill, allow the engine to lug down to peak torque (1100-1300 rpm) speed before downshifting and do not be afraid to let the engine run at low rpm if the truck will make the top without a downshift. These techniques will also operate the engine through the most fuel efficient speed range.Refer to "Driving Techniques for Maximum Fuel Economy," form LEDT5092 for more information.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