Warming up the car
Many people start their cars and let it warm up for 20 minutes. This is unnecessary.
“Warming up your car just benefits you, it doesn’t benefit your car,” Paul said. “You’re much better suited to just drive your car reasonably for the first 10 minutes until it warms up. Drive it like it’s brand new, like you just got it.”
On top of this being a waste of time, it can also be a waste of gas.