Fuel costs are on everyone's minds, and finding ways to save at the pump is a top priority. Here at North69, we believe in helping you get the most out of your vehicle, and that includes making informed decisions about maintenance. One common question that arises, especially with older cars, is whether you should increase your oil viscosity as your engine racks up the miles. Let's dive into this topic and separate fact from fiction.
The Old Wisdom: Thicker Oil for Older Engines?
The idea of using thicker oil in high-mileage engines stems from the understanding that as engines age, internal parts experience wear, leading to increased clearances. The logic was that a slightly thicker oil could compensate for this wear by:
- Filling larger gaps: Potentially improving compression and reducing oil consumption.
- Dampening noise: Helping to quieten engine sounds that can develop with wear.
- Improving seals: Creating a better barrier in older engines where seals might be less effective.
- Maintaining oil pressure: Assisting in keeping oil pressure within the desired range despite increased internal clearances.
The Modern Reality: Why Thicker Isn't Always Better
While these points might seem logical, modern engine design and oil technology paint a more complex picture. Here's why simply increasing viscosity in a high-mileage engine can be problematic and potentially lead to increased wear:
- Restricted Oil Flow: Today's engines are built with much tighter tolerances and rely on specific oil flow rates to lubricate all critical components effectively, especially during cold starts. Using a significantly thicker oil can hinder this flow, leading to inadequate lubrication and increased wear, particularly in the upper engine.
- Increased Engine Drag: Thicker oil creates more internal resistance, forcing the engine to work harder. This can result in decreased fuel efficiency – the very thing you're likely trying to improve – and put extra strain on the oil pump and other engine parts.
- Poor Cold-Weather Starting: High viscosity oils become even thicker in cold temperatures, making it harder for the engine to turn over and delaying crucial lubrication during the initial start-up phase, which is a prime time for wear.
- Incompatibility with Modern Engine Technology: Many modern engines feature advanced systems like variable valve timing that rely on the precise flow of lower viscosity oils to function correctly. Thicker oils can impede these systems.
- Manufacturer Recommendations are Key: Here's a crucial point: your owner's manual generally will not recommend increasing oil viscosity with mileage. Manufacturers engineer engines to operate optimally within a specific viscosity range, regardless of age.
The Smarter Approach for High-Mileage Engines
So, what should you do if you have a vehicle with a lot of miles on the clock? Here's our advice at North69:
- Stick to the Owner's Manual: Your vehicle's manufacturer knows best. Adhere to the recommended oil viscosity range outlined in your owner's manual.
- Consider High-Mileage Oils: Instead of drastically increasing viscosity, explore oils specifically formulated for high-mileage vehicles. These oils often contain additives that help condition seals, prevent leaks, and combat wear without the drawbacks of significantly thicker oil.
- Don't Ignore Symptoms: If your high-mileage engine is exhibiting issues like excessive oil consumption, low oil pressure, or unusual noises, a slight increase in viscosity might seem like a quick fix, but it's essential to consult a trusted mechanic to diagnose and address the underlying mechanical problems.
- Avoid Drastic Changes: Steer clear of making significant jumps in viscosity unless specifically advised by a professional.
- Monitor and Adjust (Cautiously): If you do decide to try a slightly higher viscosity within the recommended range, keep a close eye on your engine's performance, oil pressure, and fuel economy. If you notice any negative effects, switch back to the recommended viscosity.
The Bottom Line:
While the idea of thicker oil for older engines might have some historical basis, modern engine technology and oil formulations suggest a different approach. Prioritize your owner's manual's recommendations and consider high-mileage oils as a smarter way to care for your aging vehicle without compromising fuel efficiency or potentially increasing engine wear.
Have questions about the right oil for your North69? Visit our website or consult your local mechanic for personalized advice!