Do cars need to warm up, on cold winter mornings?

Dear Car Talk

Dear Car Talk | Jan 01, 2008

With the cold New England winter weather about to swoop down on us, I
have a queasy feeling in the pit of my stomach. Why, you ask? Because
every winter when my boyfriend and I get into my car, I start it, then
I put the car in gear after about 30 seconds and drive off. This
drives my boyfriend nuts, and I have to hear about "how bad it is for
my car" to put it into Drive before it warms up. He will start his car
and sit there for a good five to 10 minutes before he shifts into
Drive. My question is this: Am I really doing harm to my car by not
letting the engine run for 10 minutes? If not, how can I prove this to
him? I found an article in The New York Times a couple of years ago
that stated that nothing is gained by sitting in a freezing-cold car
while the motor is running before you shift into Drive. He thinks that
the reporter at the Times didn't know what he was talking about. But
he just might listen to you if you say it's OK. Please help! It's cold
here in Boston! -- Lisa

RAY: How do you prove it to him, Lisa? Hand him this column and ask
him to read the following aloud:

TOM: Dear Lisa's Boyfriend: You have your head so far up your tailpipe
on this one, it may be coming out your air intake.

RAY: How's that, Lisa? Will that do it? You're absolutely right, as is
the reporter from The New York Times. On modern, fuel-injected cars --
basically anything made in the past 20 years -- you're not helping the
car at all by warming it up for five or 10 minutes.

TOM: On older, carbureted cars, that kind of extended warm-up can
actually cause damage to the engine by diluting the oil with excess
fuel. So it's even worse if you have a really old heap.

RAY: But with modern cars, all you're doing with a long warm-up is
wasting gas, increasing pollution, raising the temperature of the
planet and making yourself 10 minutes late for your chiropractic
appointment. The proper procedure is to start the car. If it starts
and keeps running, put it in Drive and go. Go gently (don't back out
of your driveway and floor it right onto a highway entrance ramp),
because you'll be warming it up during your first few minutes of
driving, but DO drive it.

TOM: If it's bitterly cold out, like 10 or 20 degrees Fahrenheit or
lower, you can let it warm up for a minute or two to allow the oil to
thin out a bit and circulate completely. But other than that, if it
runs, driving it gently is the best way to warm it up.

RAY: So tell your boyfriend he not only needs to get off your case
about this, but he needs to stop warming up the car himself.

TOM: AND, to make up for all the misplaced grief he's given you over
the years, he needs to start going to bed 10 minutes before you do, to
warm up the bed for you on cold winter nights. That's a warm-up
activity he can do that's actually useful!

Get the Car Talk Newsletter

Got a question about your car?

Ask Someone Who Owns One