V writes:

Here are two questions from a regular, and grateful, Piston Slap reader:

1. How long is best to idle a gasoline engine after starting & before driving off: [A] a few minutes? [B] one minute? [C] until the revs settle down? [D] no need, just drive right off? Assume ambient temperature well above freezing; a shifting style on the sedate side; and a car made in the past 15 years so engine has EFI and EGR and all that. Current ride’s engine is naturally-aspirated and direct-injected, but I sure would appreciate knowing the proper protocol for other combinations too, if different. Several sources over the past years have all agreed on [D] for modern engines, but then just a few months back a Car & Driver column said [A], so now I’m unsure again.
2. Leaving a car (stick shift *of course*) parked: best in gear, best in neutral, or doesn’t matter? Assume the parking space is either not sloped at all, or is sloped and I know enough to turn a front wheel into the curb toward the down slope. (Read More…)