Originally Posted by PWGuy
Does warming up the car 7-10 minutes before my wife leaves for work get us any benefit with MPG?
Nope, best "warm up" for mpg & vehicle longevity is still to fire it up, then drive away "normally" - while trying to avoid any "extremes" in acceleration, braking etc. until the car has a chance to warm up.
The current crop of vehicles generally drives quite well, even when "cold" - yet ALL the systems are happier once they get some exercise & warm up to normal operating temperatures. Over the years I've seen some extremes of damage done when the operator didn't understand the importance of this. It's QUITE uncommon & any damage is usually cumulative over time instead of catastrophic. There are exceptions of course, and for automobiles winter weather is the worst. In Northern climes almost anything can break from the cold, & treating machines more gently when cold is a partial defense.