TLC for Your Car In Cold Cold Temps
Photo by Allison Sayer
By Allison Sayer
We all know cars perform differently – or not at all! – when the temperatures drop. Asking around, I have heard different things from different people about best practices for your car in the cold. I called Darrin Marshall for some definitive advice. He is a GM World Class Technician and the chair of automotive and diesel programs at the University of Alaska Anchorage. For the sake of simplicity, we just talked about gasoline powered cars.
My first question was about the amount of time a car needs to warm up. The user manual for my truck says 30 seconds, which I think can’t possibly be right in truly cold temperatures. Meanwhile, I’m sure there’s a point after which extra time is just creating pollution and wasting money.
Marshall said three or four minutes would be a minimum, especially when it is substantially cold. A minute or two might get the engine warm, but a couple more minutes are needed to warm the transmission. By the time a car has been running for ten minutes the engine is as warm as it’s going to be, idling. It will warm up more once it is loaded by driving. The user manual for my truck adds that driving slowly right after warming up is a good practice, too, to let the engine come up fully to temperature.
More idling warm-up time than ten minutes might make the interior more comfortable, but isn’t doing any more for the engine. In fact, said Marshall, “The more the engine goes around in circles, the more wear there is.”
Idling is also something you should factor into your maintenance. If you do often have your car idling, the engine is cycling more than the mileage reflects. Therefore, it is advisable to change your oil more frequently than the odometer tells you to. Marshall cited an extreme example of North Slope vehicles, which are often left running and yet show very low mileage.
Should you leave your car running if you pop into the store when it’s cold? According to Marshall, the mass of the engine means it will not cool substantially if you are just picking up a few things and will be back out in a half hour or less. You should be able to shut down and re-start your car without damage and don’t need to leave it idling. Of course if you know for a fact that your own vehicle is a bear to start in the cold that could change the equation.
High mileage cars are “more temperamental,” said Marshall, because “when your engine is brand new that piston coming up is sealed at the cylinder wall. It compresses all the air and all the fuel and when it ignites, it ignites the whole works. When it starts to wear, it’s not sealing as well and doesn’t ignite as well as it used to. It’s definitely more crucial to plug them in and keep them warm.”
Plugging cars in, admittedly easier said than done for readers off the grid, will prolong the life of your car because cold starts are what creates most of the cold weather wear and tear. The recommended time to plug a car in, according to Marshall, is at least two hours, and most manufacturers recommend plugging cars in if it is below twenty degrees. Marshall added that the two hour figure is ballpark, as the size of the engine may add some variability.
In addition to engine block heaters, it’s possible to add electric heaters to the battery and to the transmission pan. These can all be wired together for convenience. Some readers are likely all too familiar with the practice of bringing car batteries inside to keep them warm, and placing them on a trickle charger for good measure.
For on-grid residents, the prospect of more electric heaters might bring electric bills to mind, especially with the recent rate increase. Inline programmable timers can reduce the cost by automatically turning block heaters off and on according to your usual routine. The timers cost about $15. If you are struggling with electric bills, you may also qualify for state assistance through the DHSS Heating Assistance Program. See heatinghelp.alaska.gov for more information.
If a cold battery catches you off guard, look out for “overfuel” or flooding related problems. For example, if you turn the key and the battery is too cold to get combustion happening, the spark plugs can get saturated with fuel. Turning the key repeatedly will make this more likely, so once it’s clear your car will not start do not keep trying. The car will not start, or will perform poorly, until the fouled spark plug problem is addressed.
Marshall said for drivers living in cold temperatures, he would “highly recommend synthetic fluids across the board.” You can test the difference between conventional and synthetic 5W-30 oil yourself by freezing both and seeing which oil will still flow. There are also synthetic versions of other fluids, such as transmission and rear differential fluids. The viscosity of rear differential fluid, said Marshall, is much lower than engine oil, so the synthetic version will do a better job lubricating in the cold.
During the January cold snap, I felt my steering stiffen when I passed through Glennallen. I imagined it was because my power steering fluid froze. Marshall said the old-timer trick of putting a piece of cardboard in front of your radiator to keep heat in gets his seal of approval for issues such as those. He said there are also aftermarket clip-on vinyl covers you can purchase if you like. The cardboard doesn’t have any drawbacks as long as it stays cold, but you must remember to remove it in the spring. Forgotten cardboard can lead to “catastrophic” overheating when the temperatures rise again.
Many drivers swear by the use of HEET in the wintertime. Marshall explained the mechanism of HEET is that it allows moisture to be “integrated” into gas, and it will then escape from the car along with exhaust. Moisture can form where it shouldn’t due to condensation from temperature changes. Marshall said occasional use of a bottle of HEET can be a good maintenance practice in the winter. However, he also warned it’s important to stick to the one bottle:one full tank of gas ratio. Using more than one bottle per tank, or adding a full bottle to a partial gas tank, can create additional combustion problems.
Those of us who have been in the Copper Basin long enough have either heard of or tried desperate measures. I have personally set a car on fire using a product called “Quickstart.” Camp stoves, flame throwers, and other devices in the undercarriage can also lead to explosions or fires. One external “desperate measure” that might be safer, said Marshall, is to try to remove some oil from the engine, bring it into a warm environment, and then add it back to the engine.
If you come back to a cold car at the side of the road after a wilderness adventure, your resources are limited. Can a jump from a passer by be enough to start a car that has been through a big dip in temperatures? According to Marshall, it can be if the car turns over right away. However, he advises against repeatedly trying to start a car if jumping does not work within a few minutes.
Is there any temperature at which you just shouldn’t drive your car? Marshall said, “Obviously at 45 below it doesn’t operate the same,” but you won’t necessarily do damage to your car by putting it through those temperatures if it is plugged in and has a chance to warm up. “The tough part I think is safety- if you get a flat tire or run out of gas or blow a belt. You definitely want to be prepared with a sleeping bag, gloves, and bunny boots in your car. If you have to walk, 40 below gets pretty cold pretty quick.”