How do engine oils behave differently in extreme cold versus extreme heat?
It’s no secret that engine oils are the lifeblood of your vehicle, responsible for helping to ensure smooth performance, reduced friction, and lasting protection under all driving conditions.
However, what happens when the weather turns extreme? No matter if it’s a freezing winter morning or sweltering summer heat, temperature plays a crucial role in how your engine oil behaves – and how well it protects your engine.
We spoke to Texaco Lubricants’ Product & Technology Support Specialist for Europe. Rudi Sanders, to find out more about how changing temperatures can influence oil behaviour.
The cold challenge
When temperatures drop, engine oil thickens. This increase in viscosity means the oil flows more slowly through the system, making it harder for your engine to start and for vital components to receive lubrication quickly.
During those first few moments after ignition, thicker oil may:
- Not reach components fast enough, increasing the risk of metal-on-metal contact and premature wear
- Form wax crystals that clog filters and oil passages, which further restricts flow
To combat this, using a low-viscosity oil, such as 0W-(XX) grades, helps ensure your oil remains fluid even at sub-zero temperatures. These formulations can go a long way in maintaining good cold-start performance, helping to protect your engine from wear right from the first turn of the key.
When things get heated
At the other extreme, high temperatures can cause:
- Engine oil thinning, which reduces its ability to maintain a strong lubricating film between moving parts
- Increased friction, wear, and a higher risk of component damage under load
Prolonged heat exposure also accelerates oxidation and thermal breakdown, causing the oil to lose its protective properties. Additives designed to prevent wear and corrosion may degrade, while sludge and deposits can form, affecting engine cleanliness and efficiency. Additionally, lighter oil components can evaporate, resulting in higher oil consumption.
To protect against this, a higher-viscosity oil, such as (X)W-40, (X)W-30 or one formulated with enhanced thermal stability, can help maintain viscosity under heat stress, promoting reliable protection even in demanding driving conditions.
How Texaco Lubricants can help
Temperature extremes put both your engine oil and your vehicle’s engine to the test. As such, it’s critical to choose the right oil for your vehicle to help ensure smooth operation, optimal lubrication, and long-term performance.
If in doubt, always refer to your owner's manual for specific oil type, viscosity, and change intervals, as it contains information tailored to your vehicle's engine by the manufacturer.
Find out more about Texaco Lubricants’ range of engine oils.
About Rudi Sanders
Based in Ghent, Belgium, Rudi Sanders has worked for Texaco Lubricants for over 30 years. Across his career, he has held an array of positions, including being the laboratory manager of the chemical and physical test laboratory, country manager and manager of sales and marketing for Benelux and France.
Rudi is also currently chairman of the Industry Liaison Committee for ATIEL (Technical Association of the European Lubricants Industry) and co-chair of the ATIEL liaison committee for light-duty vehicles.
