"Collector" cars of all makes and models bring to mind one thing equally as much as the rare, decades-old car itself — meticulous and thorough care by an adoring owner. (In this story, "collector" cars refer to those built before 1985.) No matter if it's a 1925 Vintage Bentley, a 1932 Flathead Ford, a 1950 Jaguar XK120 or a 1975 Cadillac Eldorado, these car owners spend countless hours ensuring the exterior is waxed, the interior is kept fresh, the tires are properly pressurized and the engine clean and lubricated. Meticulous care ensures that a decades-old car will last for decades to come. When caring for their vehicles, however, collector car owners face a very unique set of circumstances, and one of the questions every adoring owner asks is, "What oil should I put into my engine?"

According to Kevin Chinn, ExxonMobil Lubricants & Specialties Global Technical Advisor, Mobil 1 should be at the top of the list for many collector car owners. "These cars are used in a variety of ways from tours, to concours, to racing, so collector car owners and their vehicles may be facing many different situations," explained Chinn.

To one extreme, for example, proper engine lubrication can be a challenge when a car is not only decades old, but rarely driven. "With collector cars, drivers may be heading to events or tours and be out for short distances at slow speeds, as opposed to long-distance, highway driving, so the oil basically doesn't have a chance to get very hot," he explained. "At such low temperatures, the oil simply doesn't heat up enough to burn off water condensation or unburned fuel." So, importantly for collector car owners, a synthetic oil should have a strong additive system to help neutralize contaminants such as acids resulting from water condensation and unburned fuel that can lead to damaged engines.

"The other extreme could be a collector car rally where the vehicles are raced and high oil temperatures are to be expected," said Chinn. "In this case, it is greater protection against wear and deposit formation that a high-quality synthetic engine oil can provide." In fact, even if not racing, it is probable that a collector car will be subject to more stressful conditions than originally intended, simply due to the nature of modern driving, which can be very different from the driving conditions of yesteryear (for example, increasing volumes of traffic leading to more stop-and-start driving).

Fully synthetic motor oils, like Mobil 1, contain high-performance fluids and a system of additives to:

:: Reduce friction and minimize wear
:: Help keep engines clean
:: Prevent rust and corrosion
:: Maintain stable oil viscosity.

The result is a lubricant that flows well at both hot and cold temperatures, and in a wide range of engine conditions. Hence, the advantages of a synthetic oil can be just as important for a collector car as the advantages are for a new car.

While ExxonMobil doesn't specifically test Mobil 1 with collector cars, the company has conducted extreme field trials that test oil in vehicles under low-mileage, low-speed conditions, and also high-mileage, high-speed conditions. According to Chinn, "Mobil 1 continually demonstrates outstanding performance even in the most extreme field trials we conduct."

With the benefits firmly established and with so many options to choose from, what viscosity should collector car owners use? "Typically, older vehicles were designed with thicker oils in mind," said Chinn. "Decades ago, the manufacturing was different. Today, the manufacturing of engines is a very precise science, and all of the parts fit together very snugly. For older cars, the manufacturing tolerance was lower, so there is generally more space between parts, and higher-viscosity oil is often the better recommendation. In addition, it is likely that higher viscosity grades contain higher levels of anti-wear additives (as measured by phosphorus content), which is better for some older engine designs."

Chinn suggests Mobil 1 5W-50 or Mobil 1 15W-50 for the majority of 1950s and newer collector cars, which typically have a modern oil-system design. "These viscosity grades should be easily available and good for essentially any collector car from Bentleys to Fords to Chevys," said Chinn. "In fact, I have a colleague who uses Mobil 1 15W-50 to help keep his 1931 Ford Model A in pristine condition, another who relies on it to protect his 1948 Chevrolet pick-up truck, and one who chooses Mobil 1 0W-40 for his 1971 Mercedes 280SL."

For pre-50s cars, Chinn says that it is always worth talking to experts in vehicle owners clubs to learn from previous experience. "If an engine has been cleaned and rebuilt, there should be no issues with using a synthetic oil, as not only should the modern base stocks and additives be compatible with all of the engine materials, including seals, but also fully compatible with any conventional oils that may have been used previously," Chinn said. "However, if the engine is worn or has not received regular oil changes, the owner would be advised to run synthetic oil initially for a few hundred miles before changing the oil and filter to ensure that any existing dirt which could initially be dislodged and removed does not overload the filter."

While most manufacturers recommend changing oil after several thousand miles, many collector car owners log relatively few miles each year. What is the owner to do? "We would recommend change intervals based more on time than miles," explained Chinn. "As with any vehicle, it is of course prudent to monitor your oil level frequently and top-off as needed, but if using Mobil 1, collector car owners could change their synthetic oil as little as once per year. For instance, use a fresh change of oil before you put your car into winter storage, because when oil remains stagnant and doesn't circulate, there is a chance for moisture and acids to accumulate and subsequently damage the engine."

No matter the make and model of collector car, a well-balanced synthetic oil such as Mobil 1 can offer valuable benefits under all driving conditions. "It should help your decades-old car drive decades into the future," said Chinn.