When the temperature drops, the engine oil thickens and loses its ability to spread. Additionally, if the oil flow is restricted during start-up, the engine parts are not lubricated properly. This may cause serious damage, which manifests itself e.g. in the form of excessive engine oil consumption, low compression pressure and a drop in engine power. Without the flow of oil, friction of metal on metal in bearings may lead to damage to the engine during start-up or reduced efficiency (stresses the Expert at Master-Sport Automobiltechnik (MS) GmbH).
In order to protect the engine at low temperatures, the engine oil must be resistant to excessive thickening and must remain liquid for easy and continuous flow. Most of the mineral oils tend to significantly thicken, as paraffin molecules crystallize at low temperatures. Unlike mineral oils, synthetic oils contain less paraffins; therefore, they remain liquid at much lower temperatures and provide excellent protection for the engine. Some viscosity grades of fully synthetic motor oils are designed to work even at very low temperatures. Also, the engine starts quicker and the wear and tear is minimized.
Notwithstanding the fact that there is oil in the engine, the vehicle should be started properly when the temperature is less than -10. What should we remember?
Avoid unnecessary rotation increase
Seeing how cars are started on winter days, we often see the driver starting the engine, and pressing the gas pedal two, three times to increase rotations. One couldn’t do worse. As mentioned above, thicker oil does not lubricate the motor bearings and metal grinds on metal. When you pump gas, you force higher engine speed, while not guaranteeing proper lubrication. The situation is even worse in the case of turbine engines. As a turbine rotates at a speed of up to 250,000 rev/min (note how a diesel engine has up to 6000 rev/min and a gasoline engine up to 8000 rev/min), and its lubrication is supplied from the engine lubrication system(!!!), any increase in the rotation in a cold engine slowly and systematically murders the turbine’s bearings mechanism.
Fire up and go
Another myth propagated by some drivers is that you should leave the engine at a standstill until the coolant warms up. In theory, the most advantageous is when you start up the engine and go right away. Then the friction associated with moving (often on slush), the operation of the crankshaft and transmission shafts in thick oil, produces faster operating temperatures than an engine running at halt. In practice, it is possible to start the engine and remove snow from the windows with the engine running. However, waiting until the engine reaches a higher temperature and only then moving the car is a mistake.
The first moments of driving
We must remember that low temperatures adversely affect not only the oil in the engine and the gearbox. Shock absorbers malfunction as well, and an increase in the density of the fluid and the operation of the valves in the damper is so greatly reduced that the first couple kilometers will make you feel as if you were driving a wagon (more on shock absorbers in a separate text). Then we have a situation where instead of damping swings of the car body, we have the metallic impact of car parts. This time before the shock absorber starts to work properly may cause damage to the shock absorber, as well as damage to shock mounts at the body and arm – which are exposed to the transmitted vibrations.
Careful with towing
When there is a problem starting the engine, many drivers decide to tow and start the engine by manually moving the crankshaft not using the starter, but the rotating wheels. Unfortunately, few people know that this increases the likelihood of rupture or skip of the timing belt. This is the result of adverse working conditions of the timing belt. While the starter rotates the crankshaft in a sustainable way, in the case of towing, there is a rapid release of the clutch and sudden forcing of rotation. The belt may then not withstand such severe stress and might skip or break. This unfavorable phenomenon is also intensified by negative temperatures, where oil becomes very thick, putting large resistance upon starting the engine.
So remember. In winter, start the engine gently and drive the first couple kilometers slowly and carefully (avoiding potholes). Furthermore, rather than relying on well-wishing neighbors who would tow your car, you should have a new efficient battery
And most importantly – the oil must meet the appropriate lubrication standards (more info about the selection of oil: see “Engine Oil, or what to look for”).
