Guys is a proper thing to do na you will rev up your engine before turning it off??? Kasi i have observed this to most of the drivers I know.... Ano kayang purpose nito and what effect does it do to the car's engine????...
Ginagawa yan ng iba para makargahan ang battery ng sasakyan. Common practice yan sa mga jeepney and truck driver. But IMO, just as what sir roydok said, it's a waste of fuel. Hindi pati applicable yan sa mga turbocharged engine.
abt sa last question mo. no need to do a full warmup. after starting, siguro you can drive slowly ng mga one kilometer in low speeds muna. that way, gumalaw ka na, without wasting gasoline, warming your engine in the process.
reving a cold engine wud damage some engine parts, lalo na if ur using mineral oil (which goes down sa sump). sa synthetic medyo ok pa (due to synthetic oils leaving a thin film of oil sa loob), pero not really advisable. atleast 5 mins mo muna syang i-idle before u go, para atleast mag circulate na yung oil sa engine mo.
yung revving before shutting down, di naman talaga kailangan (in fact di nga advisable), pero kung maganda yung tunog ng makina mo... as in ... vroooooommmm ppssssshhtttt... nakaka tempt gawin :D