Winter driving can have a number of negative effects to your car’s reliability and fuel economy. While these effects are minimized by modern engine management and fuel injection technologies, cold weather can still lead to increased stress on your engine and reduce its overall efficiency. Luckily, offsetting these effects can be accomplished by a few basic winter driving and maintenance procedures that virtually every driver can perform.
Check the Tire Pressure
Fluctuations in the temperature outside will significantly affect your tire pressure. Since air becomes denser the colder it gets, the air inside of your tires will become more compact as the temperature drops, lowering the tire psi in the process.
Insufficient tire pressure creates a number of safety hazards. Without proper inflation, your tires are far more likely to fail due to a blowout, especially when driving at high speeds. Additionally, low tire pressure leads to poor handling characteristics as well as increased road friction, which reduces fuel economy.
You should therefore frequently check the air pressure of your tires to ensure that they are inflated to the manufacturer’s suggested psi, which can be found in your car owner’s manual. This preventative maintenance procedure can be accomplished in a matter of minutes: simply unscrew each tire valve cap and use a psi reader to check the air pressure. If you discover that the tire pressure is off by more than one or two psi, most gas stations offer quarter-operated air compressors which you can use to properly inflate your tires the next time you stop for gas.
The increased density of cold air has another effect on winter driving: denser air means increased aerodynamic resistance. This means that your engine has to work harder in order to push your car through the air and maintain speed, which reduces fuel economy. Since air resistance starts to increase exponentially as you go faster, the reduction in gas mileage will be most pronounced at high speeds, such as when commuting on the highway.
To offset this effect, drive at a slower pace than usual in order to minimize air resistance. If you normally drive at 65 miles per hour on the highway, try cruising at 55 miles per hour and note the effect it has on your fuel efficiency. The price you save at the pump may be worth the small increase in time you spend commuting.
You should always change the engine oil at the mileage intervals suggested in your car owner’s manual. However, cold weather is more stressful on internal engine components, so if you do a lot of driving in the winter it’s a good idea to change the oil more frequently.
Generally, using a different oil when the weather turns cold is unnecessary. Modern synthetic oils have dual viscosity ratings that are tuned to properly lubricate the engine at both low and high temperatures. However, for drivers in extremely cold climates, modern manufacturers still sometimes suggest using an oil with a lower viscosity. Check your owner’s manual to see if this is suggested for your particular vehicle and climate.
The Engine Warm-Up Period
As a measure of preventative maintenance, many drivers like to start their cars roughly ten minutes early in the winter. This way the engine warms up and the heater works by the time you’re ready to leave. However, this habit also wastes a lot of gas and reduces your overall fuel economy.
While it’s true that the engine doesn’t perform optimally until the oil is at normal operating temperature, heating the oil with the engine at idle speed is inefficient. Even when idling, the engine uses a lot more fuel when the oil is cold, so you want the engine to warm up as quickly as possible to improve gas mileage.
Instead of starting your car several minutes early, only let the engine idle for thirty seconds or so before you set off on your drive. This gives the oil enough time to circulate throughout the engine so that it is properly lubricated. Then, drive gently for the first few minutes of your commute, keeping the engine at a low rpm speed. When internal engine components are cold they can break a lot easier, so this helps maintain reliability. However, even light driving will greatly increase the load on the engine compared to idling, which heats up the oil substantially faster. This means that you won’t waste nearly as much fuel waiting for the engine to reach normal operating temperature.