Ideal amount of time to drive my car

[Snorting2.5]

Why trans shop? Seems like an moderately easy thing to do yourself and you can guarantee it's done correctly.

If you want to drop the pan yourself, even better!

 

[Conrad 16.5]

Letting your modern car idle for an extended period is not a good idea because the fuel injection system will continue to pump extra gas into the combustion chamber. Some of it might reach the cylinder walls since it doesn’t evaporate as quickly in cold temperatures.

Gas is an excellent solvent, and a prolonged idle can cause it to wash away the oil off the cylinder walls, significantly increasing friction and causing premature wear of crucial components like piston rings and cylinder liners.

 

[7eregrine]

Idling, when cold, without any load on the drivetrain, while the engine runs rich is wearing out your engine, wasting fuel and doing almost nothing as far as warm up goes.

50 years old. Owned 15 cars. Been idling since 1986. Never lost an engine.