Uh-oh... 50/50 is not good? But -
Castrol Magnatec 10W-40 is a part-synthetic engine oil designed for various gasoline engines. The other "part" is conventional. But they keep their ratio a secret (50/50 ?). Always a fun thread to read on!
I had a conversation with AI on this topic - more specifically synthetic and semi- used in vintage motors. Occasionally AI is not fully trained in some topics but I think answers below seem right to me. Read on if your interested. I guess we found those commenting for synthetics and semi- have made some good choices. I'm not advocating as I still use conventional. Okay, pasting below - do we learn anything that Naughtycoupe, Nosmonket, Bert and Lip277 didn't know?
ChatGPT said:
Yes, vintage motors (engines designed before the advent of synthetic oils) can often use synthetic oil, but there are some important caveats and considerations:
Pros of Using Synthetic Oil in Vintage Engines:
- Superior Lubrication: Synthetic oils offer better film strength and flow characteristics, especially in extreme temperatures.
- Reduced Sludge and Deposits: They resist oxidation and thermal breakdown better than conventional oils.
- Improved Engine Protection: Especially beneficial for engines that may sit unused for long periods.
Potential Issues:
- Seal Compatibility: Older engines often used natural rubber seals that synthetic oils may degrade or shrink, potentially causing leaks.
- Cleaning Effect: Synthetic oils have high detergent properties, which can dislodge old sludge and cause clogging in oil passages if not managed carefully.
- Additive Packages: Some synthetic oils lack high levels of zinc/phosphorus (ZDDP), which is critical for flat-tappet cam engines common in pre-1980s vehicles.
Recommendations:
- Check for Seal Compatibility: Use synthetic oils labeled as "compatible with older engines" or consider high-mileage synthetic blends.
- Look for High ZDDP Levels: Use a synthetic oil formulated for classic cars (e.g., with ZDDP additives) if your engine has flat-tappet cams.
- Start with Caution: If switching, change oil and filter more frequently at first to catch any loosened deposits as synthetics have higher detergent levels.
- Synthetic Blends: A compromise option offering better performance than conventional oil while reducing risk of leaks or seal issues.
Would you like a list of specific synthetic oils formulated for classic or vintage engines?
You said:
Yes
ChatGPT said:
Yes, vintage and classic engines can benefit from synthetic oils, provided the oil is formulated with high levels of zinc dialkyldithiophosphate (ZDDP) to protect flat-tappet camshafts and other critical engine components. Here are some top synthetic oils designed specifically for vintage and classic engines.
Top Picks Explained:
- Valvoline VR1 20W-50 Racing Motor Oil: This oil is formulated with high levels of ZDDP, making it ideal for flat-tappet camshafts.
- Royal Purple HPS High Performance Street Motor Oil: Offers enhanced wear protection and improved performance for classic engines.
- PennGrade 1 20W-50 Racing Oil: An affordable option that doesn't compromise on quality, suitable for vintage engines.
When selecting an oil, consider the specific requirements of your engine, including the need for ZDDP additives, viscosity, and compatibility with vintage components. Always consult your engine's manufacturer recommendations and, if in doubt, consult with a professional mechanic familiar with classic vehicles.
You said:
does Mobile 1 have high ZDDP additives?
ChatGPT said:
Yes, Mobil 1 offers motor oils with varying levels of zinc dialkyldithiophosphate (ZDDP), an essential anti-wear additive for older engines, particularly those with flat-tappet camshafts. However, the ZDDP content varies across different Mobil 1 formulations.
Mobil 1 Oils with Higher ZDDP Levels
Mobil 1 has specific oils formulated with higher ZDDP concentrations to provide enhanced protection for older engines:
- Mobil 1™ FS 0W-40: Contains approximately 1,000 ppm of phosphorus, which translates to around 1,200 ppm of zinc. This formulation is suitable for many classic and high-performance engines.
- Mobil 1™ High Mileage 10W-40: Also contains about 1,000 ppm of phosphorus, offering similar zinc levels to the 0W-40 variant. It's designed for vehicles with over 75,000 miles.
- Mobil 1™ 15W-50: This oil has higher ZDDP levels, with phosphorus content around 1,200 ppm, equating to approximately 1,500 ppm of zinc. It's particularly beneficial for older engines requiring additional wear protection.
For vintage or performance engines, especially those with flat-tappet camshafts, it's crucial to select oils with adequate ZDDP levels to prevent premature wear. Mobil 1 oils like the 15W-50 variant offer higher ZDDP concentrations suitable for these applications.
However, it's important to note that while Mobil 1 oils with higher ZDDP levels are beneficial for older engines, they may not be suitable for modern vehicles equipped with catalytic converters and advanced emission systems. The elevated phosphorus content can potentially harm these components.
You said:
Do Castrol synthetic oils have high ZDDP levels?
ChatGPT said:
Castrol offers a range of synthetic and semi-synthetic motor oils, but their ZDDP (zinc dialkyldithiophosphate) content varies across different product lines. While modern formulations often have reduced ZDDP levels to meet current API standards, Castrol has developed specific oils designed for vintage and high-performance engines that contain higher ZDDP concentrations.
Castrol Oils with Higher ZDDP Levels
1. Castrol GTX Classic 20W-50
- Formulation: High-zinc and phosphorus content
- Designed for: Flat-tappet camshaft engines, classic cars, muscle cars, and racing applications
- Key Features:
- Provides extreme wear protection
- Maintains a tough and thick oil film under severe conditions
- Compatible with gasoline and alcohol-based fuels
- Note: Not recommended for modern engines with catalytic converters or wet clutch applications
- Availability: Available in 20W-50 grade
2. Castrol GTX High Mileage (Synthetic Blend)
- Formulation: Synthetic blend with higher ZDDP levels than standard oils
- Designed for: Vehicles with over 75,000 miles
- Key Features:
- Helps prevent oil burn-off and leaks
- Provides enhanced wear protection
- Note: While it contains more ZDDP than standard oils, it's not as high as the GTX Classic
- Availability: Available in various grades, including 10W-30 and 20W-50
3. Castrol EDGE 10W-60
- Formulation: Full synthetic with high ZDDP content
- Designed for: High-performance and racing engines
- Key Features:
- Provides maximum strength under extreme pressure
- Reduces metal-to-metal contact
- Note: Suitable for engines requiring higher ZDDP levels
- Availability: Available in 10W-60 grade