A few kilometers to the store or office seem like a harmless trifle, but it is these short trips (under 10 km, especially in winter) that are much more harmful to the oil and the engine than a multi-hour journey on the highway.
The main reason is that the engine works not by mileage, but by engine hours: in the city 100 km is about 5 hours of work, on the highway - only about 1 hour. Five hours versus one - and the oil ages five times faster. There are other reasons too.
The oil does not reach operating temperature
90-110 °C are needed for ideal lubrication. In the hustle and bustle of the city, the engine often does not even warm up to 70, and in winter - even less. As a result:
Moisture condenses in the crankcase and an emulsion forms (a whitish coating under the cap);
Unburned gasoline dilutes the oil and impairs its protective properties.
The main wear occurs in the first seconds
Up to 75% of the wear of parts occurs in the first 30 seconds after starting, while the thick, cold oil barely rises through the channels.
The amount of sludge and carbon deposits increases
The oil does not have time to “wash“ soot, wear particles and combustion products; they are deposited in the channels and on the parts.
Why factory regulations do not work here
Most car manufacturers focus on a mixed cycle, without taking into account real traffic jams, automatic starting and a harsher climate. And in our country, a large part of the cars are actually driven in “heavy mode“, so experts recommend: if you drive in traffic jams every day, reduce the service interval by half.
Signs that the oil is “tired“ prematurely
A characteristic smell of gasoline has appeared on the dipstick.
The idle pressure indicator lights up or flashes when the engine is warm.
The oil is too dark or, on the contrary, suspiciously light (it may be fake and does not retain dirt).
A white emulsion on the cover is a sign of condensation.
Each of these symptoms is a reason not to delay and simply change the oil
Change the oil more often. If your route consists of continuous short distances, change it after 7,000 km or based on the engine operating hours, and not the “passport“ 15,000 km.
Choose the right viscosity. Synthetic 0W-20 or 5W-30 are pumped faster when cold. Look at the tolerances, and for a more thorough assessment - the flash point and evaporation: the higher the first and the lower the second, the more reliable the oil is when overheating.
Give the engine a minute. In winter, warm up the engine for at least 60-90 seconds after starting (longer - excess carbon deposits, less - dry friction).
Do the so-called. in colloquial language “purging“ once a month. 30-40 km of continuous route will evaporate moisture and help clean the system.
Monitor the condition. Rapid blackening, emulsion or drop in level are signals to switch to more frequent maintenance.
Short city trips are the main enemy of engine oil: the engine remains cold for a long time, moisture and fuel get into the lubricant, and the engine operating hours increase exponentially.
The only reliable way to avoid premature wear is to reduce the replacement interval and choose an oil designed specifically for frequent cold starts. It is always cheaper to replace consumables on time than to repair the power unit, experts note.