Engines Adequate maintenance of the engine, which is the re- sponsibility of the owner/operator, is essential to keep the emission levels low. ate in the top gear at reduced rpm, rather than in the next lower gear at the maximum rpm. The driver should be familiar with the vehicle warning system in order to bring the vehicle to a safe stop if the engine malfunctions. If the driver doesn’t understand how the warning system works, an engine shutdown could occur causing a safety hazard. See Chapter 3 for information on the control panels for the various en- gines. 3. Cruise at partial throttle whenever road conditions and speed requirements permit.
This driving tech- nique permits operating within the most economical power range of the engine. 4. Use lower gears in steep downhill driving. Normally, the gear used to descend a hill is the same gear used to climb a hill of the same grade. Mercedes-Benz 5. Never allow the engine to exceed the rated speed. Use the exhaust brake and the optional constant- throttle brake, if installed, to lower engine rpm be- low the rated speed. While you are driving, watch for any signs of engine problems.
If the engine overheats, uses excessive fuel or lubricating oil, vibrates, misfires, makes unusual noises, or shows an unusual loss of power, turn the en- gine off as soon as possible and determine the cause of the problem. Frequently, engine damage may be avoided by a quick response to early indications of problems. 6. Never allow the engine to idle for more than 30 minutes. Excessive idling can cause oil to leak from the turbocharger. CAUTION 1. Use the tachometer to determine when to shift. Fol- low the pattern on the shift lever when moving through the gears. Stop the engine at the first sign of malfunction.
Al- most all malfunctions give some warning to the op- erator before significant damage occurs. Many en- gines are saved because alert operators heed the warning signs (sudden drop in oil pressure, un- usual noises, etc.) and immediately shut down the engine. 2. Depending on the vehicle gearing, the posted speed limit can sometimes allow operation in either of the top two gears; however, for improved operat- ing efficiency (fuel economy and engine life), oper- 4.9