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Myth or Fact starting your car occasionally in extreme cold is good

I live in Montana. Many nights in a row the temps can be -20 or more below 0. Next week we will have highs of -6 during the day. I don’t have a block heater or oil pan heater. I have lived here all my life and have always started my car every 6 hrs. or so throughout the night to “warm up the battery” and run oil through the engine when it was going to be extremely cold. #1. Is it fact or fiction that this helps ensure my car will start or does it just wear the battery down and burn up gas?. #2. Is there benefit or harm to having the defrost, heater/fan on? I have a remote start.

If you park in an attached garage I would not do that. Parked outside I think I would just keep a good portable battery jumper pack handy. As for doing any harm as long as you let it run long enough to reach full temperature it should cause problems. The heater should be on.

Well, in college in South Dakota, when it got that cold, I would have to go out and drive my 59 Pontiac around to warm it up every four hours or it would not start in the morning. Just running it though is not as good as driving it to fully warm everything up. On modern cars it should not really be necessary with fuel injection but at -20 I still wouldn’t want to chance it. My neighbor’s fairly new truck sits out and he has had to have it jump started when it gets that cold. So I guess yeah, I would warm it up, but I would drive it, and six hours is probably a little unnecessary-depending on your car and its condition.

There is no need to do that.

Since “cold starts” are when most cylinder wall wear occurs, you’re not helping your engine. But on the flip side, you’ll likely never experience the negative effects of that wear.

Keep starting it every 6 hours only if it makes you feel better. Your car doesn’t care.

That brings back memories!
One of my college friends had a car that he needed to start and run every 4 or 5 hours in the winter in order for it to start the next morning, and it was–guess what?–a ’59 Pontiac!

Hmmm…was it by any chance a white, 2 door Catalina?

years ago friend had auto car starter that ran motor when it got to 32f. this was precomputer days. you would think with all the new remote car starters and push start ignition that some sort of temp sensing control is available. than motor is always “warm”. seems to me with a good battey that subzero starting on warmish motor will be easy, till u run out of gas

Thankyou for your input. I hate a 1970 Dodge Dart that I spent more than one Winter morning using to jump starting my neighbors around town

Thankyou. I usually take my keys to bed. Beats the old days of getting up and staying up to go out at start the car.

Thankyou all. We also add “heat” brand ice preventer to our gas tanks at a fill-up when we know it’s coming.

@vdcdriver Well it was a four door Catalina with a white top but the body was canyon copper. One of the guys I used to take it to said it was the engine was too big for the starter. Maybe I dunno. The other thing was I’d have to pump the dickens out of the gas pedal to get it to start. Yeah and the carb had been overhauled several times. I suspect now, 50 years later that it had that leaky float bowl that drained all the gas overnight. Hard getting used to fuel injected cars that just start-period, without even touching the gas. Youth today just don’t know what they missed out on.

Interesting that one of my roommates had a 55 Pontiac and when it was really cold and wouldn’t start, he just left it for a warmer day. Then it started.

Virtually every part of the car, including the battery is better than when this procedure was created. Modern cars are designed to start at 40 below zero (F or C!). Modern batteries have way more cold cranking amps than the lumps we had in the 60’s and 70’s. Synthetic oils can make it much easier to crank a really cold engine if you want little more insurance. And the final kicker; buy a “Jump Pack” portable car jumper and keep it warm inside just in case the car just needs a little more help.

FWIW, Jump packs contain a battery, charger for that battery and jumper cables. Some have lights and air-pumps, too.

That is exactly what my friend, Charlie, had to do in order to start his Catalina…
In retrospect, I think that you are on target with the suspicion about the leaky float bowl.

blockquote, div.yahoo_quoted { margin-left: 0 !important; border-left:1px #715FFA solid !important; padding-left:1ex !important; background-color:white !important; } Thanks for the response.

Terri L. Randall

I wonder what all this extra fluff is? How do you get this in a reply?

You are welcome, Terri, BTW.

Why not just get a block heater installed and sleep through the night? In ND the apartment complex I lived in had outlets in the parking lot. Was $150 I think for a block heater. @mustangman incorrectly formatted code!

I was stationed in North Dakota for three years and I had an engine heater.
Starting the car every four hours or so is bad… it messes up your circadian rhythm! :grin:

There are too many variables to make a sweeping statement about engines. Parts change dimensions when cold, and in extreme cold they change dimensions extremely.

Thermal expansion happens in a “photographic” manner, meaning they change as if one were enlarging or shrinking a photograph. And different materials have different “coefficients of expansion”. That means that an iron block with an aluminum head changes differently than an aluminum block with an iron head. The “photographic” part means that a piston 2-1/2" in diameter changes more than a piston that’s’ 1-1/2" in diameter. And an aluminum piston in an iron block is affected differently than a steel piston in an aluminum block.

Engines also heat up and/or expand/contract in different patterns. A big V8 will heat up differently than a small inline 4.

Much of the reason that you’ll get a wide variety of answers is because there are a wide variety of engine designs, a wide variety of experiences, a wide variety of technical backgrounds, and a wide variety of beliefs on the subject, and an endless well of myths and anecdotes.

In short, I don’t think there’s one answer. Overall, I think the smart thing is to give your engine all the help you can. If you have a garage and it’s full of ladders, lawnmowers, tools, and grass feeds, it might be a good idea to get a shed for all that stuff and park the car in there. It takes a surprisingly long time for all the engine’s internal heat to fully dissipate, especially if it’s big iron V8, and at least some of the heat will still be in the garage in the morning.

If you have no garage, but do have access to a 115VAC plug, an engine heater is a great idea.

If you have neither, put a thermal blanket over the engine when you bed the car down. You can buy one at any parts store that’ll be safe.

Post your decision. We do care.

delete please

Another +1 on installing a block heater, or oil/coolant heater. Carrying a jump start pack is a good practice also.

I suggest that you get a magnetic oil pan heater and for good luck a small battery maintainer. The heater will take the sharp edge from the cold as your engine sees it and the maintainer will keep your battery as sharp as it can be in the cold. Then sleep well and don’t get up until morning!

Synthetic oil helps a lot; it’s what we stumbled across in the early days when it first became available to get my wife’s VW diesel started on cold days after she left work for the day here in Wisconsin. At her job, of course, there was no outlet to power a heater. Synthetic oil permitted the starter to spin the engine faster.

I used to live at around 6500 feet on the western slope of the rocky mountains. The winter nighttime temps didn’t typically get to as low -20 F like there in Montana tho. -5 or so would be as cold as it would typically get at night. I parked my truck outside all that time and never did anything special at all for the cold temperatures. Other than driving it every day of course. Rust, that’s another story , I had to do a lot to control rust from the salted roads.

So now you understand I have absolutely no experience dealing with -20 deg F temperatures and their effect on vehicles, my suggestion is rather than continually starting the engine, other than making sure the coolant has the needed freeze protection and you are using an oil viscosity appropriate for those temperatures, to just keep the battery charged fully when the vehicle is parked overnight by connecting up to a battery charger or battery tender, aka float charger.