804869 Volvo.Penta Screw

Engine Operation
* Begin operating the engine at low load. After normal oil pressure is reached and the temperature gauge begins to move, the engine may be operated at full load.* To get the vehicle in motion, use a gear that will result in a smooth, easy start to move the load without increasing engine speed above low idle or slipping the clutch. Engage the clutch smoothly. Interrupted slipping and abrupt clutch engagement put stress on the drive train and waste fuel.* Use progressive shifting to reduce fuel consumption. Progressive shifting is using only the rpm required to make an upshift into the next gear. The amount of rpm required to make an upshift increases as the vehicle/truck speed increases unless upshifts are made on upgrades. Experience with your vehicle/truck will show you how much rpm is required to make upshifts under various conditions.* If the vehicle/truck can be operated in a higher gear after the desired speed is reached, select the highest gear available that will pull the load. By following this recommendation, you will lower your fuel costs. Your engine will be operating at the lowest rpm required to pull the load.Fuel Economy
Fuel is the largest single operating cost of today's on-highway truck engines. Improved fuel economy can have a substantial impact on operating profit. The most significant factors that influence vehicle fuel economy are:* Driver techniques* Vehicle efficiency/Truck Specifications* Operating conditions* Engine efficiencyDriver Techniques
The manner in which a vehicle is driven 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 following tips can optimize fuel economy by making maximum use of the potential efficiency of the engine and vehicle.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.Uphill Operation
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.For best performance when climbing a hill, allow the engine to lug down to peak torque (1560 rpm) speed before downshifting and allow the engine run at a lower speed (down to 1400 rpm) if the truck/vehicle will make the top without another downshift. Fuel economy will be best if you let the engine lug back to around this speed before you downshift. Downshift until a gear is reached in which the engine will pull the load. This technique will also operate the engine through the most fuel efficient speed range.Allowing the engine to lug below peak torque is permissible if the truck/vehicle is cresting the top of a hill without downshifting. However, note that extended operation in a lug condition will raise exhaust temperature and cylinder pressure. This can lead to reduced engine life.
DO NOT allow the engine rpm to exceed 2900 rpm, engine damage can result.
Downhill Operation
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.* On a downgrade, do not coast with the clutch disengaged or put the transmission in NEUTRAL. A simple rule to follow is to select the same gear that would be required to go up the hill. However, DO NOT allow the engine to overspeed.* Select the correct gear that does not allow the engine speed (rpm) to exceed the 2900 rpm limit and use the engine retarder and/or service brakes to limit the speed of the truck. Refer to the rated (full load) rpm as shown on the Engine Information Plate.Saving fuel on 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 (1560 rpm), the truck/vehicle 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/vehicle 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.Starting Out
This truck engine does not require long warm-up times that waste fuel. It takes just a few minutes in the summer and a bit longer in the winter to warm up the engine. Keep engine rpm (speed) at a minimum. Use just enough rpm to pick up the next gear. This technique is called progressive shifting. It can improve fuel consumption and will not harm the engine.Progressive Shifting
When accelerating under normal level road conditions, the engine should be operated in low to mid rpm range (1100 to 1600 rpm) 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