Are Synthetic Oils Safe for Classic Vehicles?

There has previously been concern about the use of synthetic oil in treasured classic vehicles. However, with the use of modern technology and improved industry knowledge, there is no longer any need to worry. The Millers Oils Classic Vehicle Range includes engine oils with mineral and synthetic based blends.

What defines a classic car?

Although there is no specific time period to determine a classic vehicle, Millers Oils approximates classic vehicles to be from around the 1940’s – 1980’s/90’s, and modern classic vehicles to be from the 1980’s/90’s. Vehicles prior to this have even more specific needs than classic vehicles and are classed as vintage.

What’s the difference between mineral and synthetic oil?

Oils used to formulate lubricants are called base oils, and include both mineral and synthetic types:

Mineral oil is refined from a fraction of crude oil, using different techniques including solvent washing and chemical reactions to remove impurities, and improve lubrication characteristics.

Synthetic based lubricants, although still derived from crude oil, are manufactured using chemically modified petroleum components or are synthesised from other raw materials, rather than the refining of crude oil. This is a much more controlled process, meaning that the molecules in the oil are more uniform.

Why is there reluctance behind using synthetic oil in classic vehicles?

In the late 1990s, synthetics were a new and increasingly popular technology. Oil companies began to introduce synthetic blends into their classic oils, but classic car owners started experiencing oil leaks. Classic vehicles had rubber seals designed to be used with mineral oils, so some compatibility issues were discovered. The synthetic oils caused the rubber in the seals to perish and weep, leading to the leaks.

Are synthetics safe to use in classic cars today?

After years of research and testing, we are a lot more knowledgeable about synthetic oil technologies and additives. Millers Oils has developed a synthetic product range for classic vehicles that not only eradicates past issues with rubber seal compatibility, but further protects your vehicle with the potential to enhance performance.

Millers Oils synthetic based classic engine oils range from Classic Pistoneeze, to Classic Sport and Motorsport Classic High Performance, depending on your application requirements. Classic car owners can now experience the benefits of modern technology with all the charm of driving their classic vehicle.

What are the benefits of synthetic oils for your classic car?

• Better lubricity for better protection on high stress areas, extending the longevity of vital components.
• Improved viscosity index, meaning better and more consistent performance across a wider temperature range.
• Higher thermal and oxidative resistance, so the oil is less likely to degrade due to high temperature or contamination, meaning fewer deposits and less sludge, as well as extended drain intervals.
• A stronger film thickness leads to a higher level of protection.
• Reduced volatility and evaporation losses, resulting in lower oil consumption.

Read about the effect of ZDDP on vintage and classic cars here. 

Find our Vintage and Classic product range here. 

For more information, refer to Millers Oils Classic brochure.