Hi guys and gals,

I have possibly the dumbest question in the world. It's about warming up your car. I keep my cars I buy for a long time before I sell or trade them (16 years on my last one, a 97 BMW Z3) and now that we're moving into the winter months, I was wondering if anyone has any idea how long we should wait for the car to warm up before we begin driving it. I have a mechanical engineer friend who claims driving the car after you immediately turn it on should have no ill effect on a car, but I don't believe him. I know many other people who would say, no, you have to wait at least a few minutes, maybe even 5 before you drive, especially when it's cold. What I've done with my Z3 was listen to the sound of the car. When you first start the Z3, it would emit a higher pitched hum which would gradually get lower and lower until it just sounded like it was ready to drive. My MINI emits the same sounds. I start my MINI, it would emit a higher pitched hum which would gradually get lower and lower until it just sounded like it was ready to drive. That lowest hum would sound throatier (I have a JCW exhaust). I also use the gauges. When the car is first started, the needle on the RPM gauge is above 1000 (see pictures below). At the lowest hum, it dips below 1000. That's when I know it's "safe" to drive. This might just be a superstition (or "stupid-stition"?) on my part. What's the truth?

Oh, yeah, I know 57 degrees is not cold. I was just using the pictures to serve as examples in my description above.

 

Modern fuel injected cars don't need the long warm up periods. I start my car, let it sit for a moment while I get my music going and any other quick chores and then move out slowly for a few blocks.

 

I usually wait for the start-up fast idle speed to settle down before driving off. Then, try to keep it out of heavy boost until the exhaust starts to pop in sport mode.

 

Thanks for the input Minnie and Nik!

 

Your friend is absolutely right. Modern cars do not need to be warmed up. In fact, letting them warm up may even be marginally worse than just taking off immediately after startup. The engine is turning over regardless of whether you are driving it or not, and letting it idle at such a low temperature actually keeps the oil cooler for longer, meaning it doesn't flow as well. Plus the oil pump isn't turning over as fast meaning less oil pressure. If you just start driving you'll get everything up to temperature faster and flow more oil through the system more quickly.

 

Driving it right away is best for the engine for the reasons already stated.

 

I have been told that you should wait for 1 minute, then drive an a normal pace but try to limit the RPM's to about 2500 until the car is at its normal operating temperature.

Once at the normal operating temperature you are good to go to higher RPM's as needed or want.

 

It sounds different because the idle rpm is different. Idle rpm is higher when engine is cooler. I just wait a few seconds before driving off and go easy for a couple of minutes.

 

I'm with the others, no warm up necessary. Just drive the car gently until up to full temp. If very cold (say below 20-deg F or so) a minute or two of idling to get a little heat into the engine before driving is a good idea. But as soon as the engine can take load without distress, drive it (gently at first).

- Mark

 

Yea, I start right out, let it idle in 1st down the alley (bout 1/2 a block) then head out shifting at 2000 RPM till the temp gauge comes off the pin.
An aside: My father in law was a road man for a large company and covered the east and west half of two states. He was issued a Ford Crown Vic by the company. He would go out to the garage of a morning, fire up the car then go back in the house for 10 or 15 minutes before driving away. He'd put between 300 to 500K miles on one then get it replaced. He NEVER changed the oil, just added as needed. I vowed to never buy a used Crown Vic.

 

If he is putting 500k miles on the car, and only adding oil as needed, why wouldn't you buy it?! Those things are bullet proof!

 

It was the mystery of what else he may have neglected that always cautioned me. Besides, by the time I was acquainted with that issue, we had a growing family and moved to the Chevy Caprice wagons, put about half that mileage on each of two of them before kicking the kids out and downsizing to MINI.

 

There are legions of folks who live in N climates who routinely start a car in the morning (typically remotely) and then have a cup of coffee and read the paper. They love coming out to a car that is completely warm. So its not like anything terrible is likely to happen and old American V8s will take incredible abuse before they give up the ghost. Our Minis are cut from a different cloth. Regardless, this sort of regimen isn't ideal. And it wastes a lot of gas.

- Mark

 

Fleet cars too, parts are dirt cheap. I'd love a used Crown Vic except for the gas.

 

You'd be way late on any of his, he died 30+ years ago.