The debate among car enthusiasts about whether to use P (Park) or N (Neutral) gear when warming up an automatic car has been ...

In our tests, we've found that in some cars a manual transmission can improve gas mileage by a significant 2 to 5 mpg, compared with an automatic, and can cut a car's price by $800 to $1,200.

The debate over whether to use P or N gear while warming up an automatic car has persisted among car enthusiasts for many ...