What is Winter Driving Like?
In Russia this year, frost arrived with surprising intensity. The northern regions faced temperatures around minus 60 degrees Celsius. That is genuine winter. In contrast, a southern winter features light snowfall that dusts the grass while the air still hovers near freezing. It’s a reminder that weather patterns vary greatly, and the approach to car maintenance, the choice of lubricants, and the fluids used must adapt accordingly.
No car maker mandates a single engine oil produced with a specific technology. Instead, labels indicate the operating category such as SL, SM, SN and the viscosity grade such as 0W, 5W, or 10W under the SAE system.
Oil selection is influenced by temperature
Today’s manuals increasingly single out one oil for a given climate, for example 0W-20. For older vehicles, more viscous oils were often recommended, like 10W-40. In some cases, military practice has involved using thicker oils for engines showing wear.
The question arises: can oil be chosen on any basis, mineral or synthetic. The nuance is that mineral oils with the first figure before the W, such as 0W or 5W, do not exist in certain contexts. The first digit is a guarantee about minimum operating temperatures for starting the engine. If 0W is specified, crankshaft rotation is ensured down to minus 35 degrees Celsius, and pumpability down to minus 40 degrees Celsius. The oil maker confirms that the product will retain its viscosity within the SAE limits at those temperatures.
Most mineral oils start at 10W, which limits their cold-start performance. A table shows the maximum start temperature around minus 25 degrees Celsius. If the region does not experience severe frosts, such mineral oils may still be used under specific conditions.
SAE low temperature viscosity requirements for engine oils
| SAE class | Maximum viscosity, mPa·s at specific conditions | |
| cranking | pumpability | |
| 0W | 6200 at minus 35 C | 60,000 at minus 40 C |
| 5W | 6600 at minus 30 C | 60,000 at minus 35 C |
| 10W | 7000 at minus 25 C | 60,000 at minus 30 C |
| 15W | 7000 at minus 20 C | 60,000 at minus 25 C |
| 20W | 9500 at minus 15 C | 60,000 at minus 20 C |
| 25W | 13,000 at minus 10 C | 60,000 at minus 15 C |
Choose by quality
Mineral oil enthusiasts may face a limitation: the service category, or quality level, for mineral oils currently tops out at SL. By modern standards, that is a long-established baseline. It was gradually replaced by the progressive categories SM, SN, SN+. Today the highest standard is SP. Therefore, if a vehicle’s manufacturer specifies oils of a higher category than SL, mineral oil should not be considered a viable option.
Oil quality matters
The temperatures listed in the table apply to fresh oil. This is a detail often overlooked by car owners and sometimes by professionals alike. With thousands of kilometers on the engine, oil performance can decline. Resins and deposits build up, causing the early viscosity to decrease and the cold-start temperature to rise by about five or six degrees Celsius, which reduces the margin originally suggested by the SAE specification.
At the market, both synthetic and mineral engine oils are available. Synthetics come in many forms, while mineral oils are generally limited to SAE 10W and above and do not exceed the SL category in practice. The takeaway is clear: mineral oil is not ideal for winter use because early engine start attempts may suffer and fuel economy can suffer as a result.
In practical terms, switching the oil type can be sensible in specific high-mileage, naturally aspirated engines. A thinner synthetic oil may leak past seals in an older engine, which can be mitigated by choosing mineral oil but requires more frequent changes, roughly every 7,000 kilometers. This is a tradeoff that often does not deliver long-term savings. If a mineral lubricant is used, it is important to thoroughly flush the old oil from the engine during a change.
As a general principle, winter lubrication should prioritize reliable cold-start performance and stable pumpability. This is supported by independent technical guidance from the Avtodom Group’s service specialists, which emphasizes careful consideration of engine condition, mileage, and climate when selecting an oil regime. The guidance is intended to help drivers avoid starting problems and protective wear—especially in severe cold conditions.