Winter is far away. But the frosty time is already creeping up to the horizon. And it means that very soon the fires of confrontation between motorists and bloggers on the topic: warm, not warm, will erupt with renewed vigor in the expanses of the Internet. And in case anyone didn’t understand, we are talking about warming up the engines of modern cars. It’s time to try to figure out why the internal combustion engine does not like the cold so much.
There are several reasons why internal combustion engines do not like the cold. However, the main reason is that absolutely any engine oil starts to get thick at subzero temperatures. This problem was actual for automobiles in the XX century, it does not lose its urgency in the case of modern cars. The mineral oils stop flowing already at minus 20-25 degrees Celsius. The situation with synthetic oils is much better. They stop to flow at minus 45-55 degrees Celsius, however up to that moment they also become dense. Due to thickening of the oil, friction in the engine is “dry”, which causes the occurrence of two negative moments. The first is accelerated wear of engine components. The second one is the increase of fuel consumption due to the sharply increasing mechanical losses.
On the expanses of the Internet are constantly breaking spears not only on the question of whether it is necessary or not to warm up modern cars in principle. How to do it correctly is hotly debated. The basic positions in the dispute three: do not warm up at all, warm a little, while brushing the snow from the car, warm thoroughly for 10-20 minutes. In fact, to understand this question, if you want, every owner of modern cars can. All you need to do is to make a series of experiments and compare data of an onboard computer. As an example, it is possible to take the data from one popular European car of Euro-4 standard of 2005 year production with 1,6 liters engine, working in the mode “from house to work” in conditions, when it is -15 C outside.
It is better not to warm up at all. Started in frost and immediately drove. We don’t see anything good on the computer. Fuel consumption from the standard 6.5 liters immediately jumps to 10 liters. During the 5 km drive to work the consumption didn’t manage to go down to the standard level, stopping at 6.8 liters. Spent 0.45 liters of fuel.
Warmed up for 5 minutes. Started, cleared the snow and ice, only then drove. At idle before departure the consumption was 1.3 liters. With the start of the trip it jumped up to 7.6 liters, and after 5 km of driving it went down to 6.6 liters. As a result, 0.55 liters of fuel was wasted.
Warmed up 10-20 minutes. Started the engine. Consumption at idle 2.5 liters. In 10 minutes – 0.9 liters at idle. In another 10 minutes – 0.8 liters at idle. During driving the consumption drops to 6.4 liters per 100 km. Total with taking into account the run of 5 km around the city and the warm-up it was spent 0.33 + 0.45 = 0.8 liters.
Obviously, prolonged warming up in the end noticeably increases fuel consumption. However, we should not forget about point 2: engine wear and tear. It is not easy to estimate it. Everything is individual for each car. It is the luck of the draw. For one car with one engine, 5 km of run without warming up will cost 20 km of run in normal conditions. For another it could be as much as 100 km. First of all, the engine pistons suffer from driving in the cold. Therefore it is possible to say with all certainty, that it is still necessary to warm up the car in winter. It is better to stop on an intermediate variant – to warm up a car up to 5 minutes, while you clean snow and ice. This approach will help your engine, and will not burden your wallet too much.