Rev Engine Before Shutting Down

[xxxancientxxx]

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no nid just waste of money/gas

[D6045]

OT: medyo OT gamay, pero ask lang ko, dli ba mas daghan ang unburn fuel sa low rpm?

If the rpm is low how are you putting alot of unburned fuel if you're not forcing fuel? While reving up the engine, it's forcing a stream of fuel leaving it unburned while shutting it off.

[jojo_mouth]

Thou shall not rev high before shutting the engine.. It must settle to its lowest rpm for a short while before shutting it. You are just making it hard for the engine if you rev and turn off. Just like you running and suddenly stop to stand still hehe diba mas maayo if from running then jog then walk for a while then ayha stop? Rev up before shutting is nothing but waste of fuel and add more wear & tear to engine internal parts.

For turbo engines, it must stay a little longer and must be at the lowest rpm state. This is becoz the turbo is spinning 10x the engine speed, so when you turn off the engine, the turbo is still spinning for a minute or so with out the lubrication this time becoz the engine is shut of and the oil pump is no longer working. Mao ni makadaut sa turbo if it still spinning for a minute or so without lubrication. Madaut gyud ang bearing.

Before, cars were not equip with alternator, they use generator (Direct Current). They dont have voltage regulator, so if they rev their engine, it is are charging more than 14volts-18volts and that charges the battery more (batteries long time ago is not as efficient as today's technology, usually died faster). It became a habit of revving (increase charging) before shutting off so they have assured battery power when they use it later. But today's alternator has voltage regulator that only limits 13.8 volts to maximum up to 14.2 Volts no matter how high you rev.