Informing Doctors about Automobile Motor Oil Changes

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What doctors need to know before their next service

[By Dr. David Edward Marcinko MBA and Nalley Lexus-Roswell]

DEM 2013Chances are you might have heard a thing or two about oil prices and all the work it takes to get it out of the ground. You may have even walked into an auto parts store and seen a wall filled with a plethora of different types, viscosities, and brands of oil. Luckily, there are choices to be had, and we’re here to walk you through them.

To Lubricate – Not Burn

Right off the bat, the point should be made clear that motor oil is not meant to be burnt. Sure, oils are used to make the gasoline and diesel fuels that power our vehicles, but motor oil is purely there to lubricate the internals of your engine, not to be burnt as an energy source. It’s that type of burning that causes some of the environmental issues. If you notice a blue smoke emitting from the tailpipe of your vehicle, and the need to add oil every so often, your engine might have a serious problem.

But, for normal motor oil usage, the lubrication of engine internals to keep metal from touching metal while the various bits and pieces move a couple thousand times a minute, there are basically two types – conventional and synthetic.

My Jaguar's engine after a steam

Conventional Oil

Conventional motor oil has done a great job for the past hundred years or so, and is still largely the norm when it comes to servicing your vehicle. Why is this? For the vast majority of drivers in normal vehicles, conventional motor oil meets the vehicle’s needs while being lower cost. In fact, a quart of conventional motor oil will only set you back half of what a quart of synthetic oil costs.

What are some of the benefits of conventional motor oil? First of all, there’s the cost proposition. And if you drive a normal vehicle, conventional oil might actually be a better choice, as it’s a thicker substance. Also, for that same reason, conventional oil is often the lubricant of choice in higher-mileage engines, where some worn components might not have the ability to seal that they once had.

Synthetic Oil

Synthetic motor oil, however, is the new wave of engine lubrication. First designed for aircraft applications in the 1970s, it has also found a home in the engines of many high-performance vehicles. With the requirement of maintaining lubricating abilities at high altitudes and temperatures in aircraft, it was a natural fit. Because of the higher tolerances of aircraft and high-performance engines, the thinner nature of synthetic oil is meant to squeeze into every nook and cranny available, exactly what is needed in these finely-crafted engines.

While synthetic oil might cost twice as much as conventional, it’s thermal properties that keep it from breaking down over time mean that oil changes can occur less often at higher mileage intervals, saving you headaches and recouping some of those costs. Also, due to its thinner nature, it flows easier in cold weather, meaning less warm-up time for your engine, decreasing, once again, headaches and harmful exhaust fumes.

My Kitty Oil

I’ve got a near showroom and mint conditioned 2000 Jaguar XJ-V8-LWB. It  is a full-size luxury sedan, offering sporting drive characteristics, mixed with a classic style and interior comfort. It was available in multiple trims which all came very well equipped with upscale amenities. And, this extended wheelbase version offers much more rear seat leg room for long and winding Georgia road trips. The standard steel engine [not nikasil] in this XJ is a 4.0L V8 which produces 290 hp. The upper and lower timing chain tensioners are original, second generation metal, not plastic.

There is also a supercharged version of this vehicle which bumps output to an impressive 370 hp. Even with all of its power and weight, my XJ-8-L is still rated at over 20 mpg on the highway. Ammenities and upgrades include a mobile phone, Magellan GPS, LoJack theft recovery system, CD and MP-3 players, with internal and external cable antenna for satellite radio.

As for oil, my owners manual calls for 10w30 as preferred, but 10w40 is acceptable for hotter climates like Atlanta. Since my XJ-8 has 90,000 miles on it, I tend to use something a little thicker 15w40 and might used 20-50 come summer if it starts consuming in the high heat.

What a Cat!She is my third favorite female after my intelligent and beautiful wife, and smart and lovely daughter.


Now that we know the key differences in the available types of motor oil, which should you choose at your next service? For that, your mechanic will take into account your driving style, vehicle mileage, and other factors, and help you decide what is best for your vehicle.

XJ-V8-LWB Jaguar touring sedan



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Speaker: If you need a moderator or speaker for an upcoming event, Dr. David E. Marcinko; MBA – Publisher-in-Chief of the Medical Executive-Post – is available for seminar or speaking engagements. Contact:


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6 Responses

  1. Mixing Oils

    I do not recommended routinely mix oils because the additives in different products may interact or the oils may become destabilized by the mixture. You may reduce or negate the properties of the additives, and you’ll lose the benefits of the more expensive synthetic oil.

    So, adding regular oil to your special synthetic oil will mean you’ll need to get your oil changed sooner than you would have otherwise. If you have a high performance engine, it’s possible it will be displeased if the (expensive) additives can’t work the way they are supposed to. This may not damage your engine, but it won’t help its performance.


    1. Have you ever mixed oil, either accidentally or on purpose?
    2. Was your vehicle fine or did it suffer any ill effects?

    The Editors?


  2. Some Synthetic Oil Myths

    Myth: I need to flush my engine before switching to synthetic oil.
    No special preparation is necessary when switching from conventional motor oil to synthetic or from synthetic back to regular oil. You can even mix them.

    Myth: Synthetic motor oils damage seals.
    Untrue. Seals can actually last longer with synthetic oil.

    Myth: Synthetics are too thin to stay in the engine.
    Untrue. In order for a lubricant to be classified in any SAE grade (10W-30, 10W-40, etc) it has to meet certain guidelines with regard to viscosity (“thickness”). Synthetic oil will actually stay thicker in hot conditions.

    Myth: Synthetics cause cars to use more oil.
    Untrue. A leaking engine will leak the same amount of either. Unless an engine is a real oil burner, it will burn less synthetic than regular.

    Myth: Synthetics void warranties.
    Untrue. No major manufacturer of automobiles specifically bans the use of synthetic lubricants. Some are using it as factory fill in high performance engines.

    Myth: Synthetics last forever.
    Untrue. The additives still wear out and dilution degrades the oil.




  3. Hi Dr. Marcinko,

    Sorry for my English. My name’s Hubert and I’m 17. I know you like Jaguar automobiles. I help my uncle to find parts for Jaguar Mark X.

    He bought two Jaguar’s Mark X, one in USA (Old English White) and one in Belgium (English Race Green). Each one has been shipped to Poland. He wants to restore one. Here is an original video



  4. Oil’s well – Know it, change it, check it

    Modern engines are manufactured with incredibly tight tolerances and are designed to operate with very light oil that also improves fuel economy. The vehicle’s owners manual or a label on the oil-fill cap will indicate which engine oil to use.

    As part of emissions regulations, oil-change intervals have been stretched from 3,000 to 7,000 and even 10,000 miles. It’s not necessary to change your oil early, but don’t go longer than the factory interval.

    So, check your oil at every other gas fill-up and keep it topped off. Just because you can go 7,000 miles between changes doesn’t mean your engine won’t consume some oil.



  5. Don’t forget other fluids, too!

    We all remember oil. Unfortunately, few people think about transmission, power-steering or brake fluids until there is a serious problem. Everything should be at the proper level and the appropriate color.

    Your oil should be a honey-brown to brown color, while the transmission and power-steering fluid should be bright red. Your brake fluid should be clear to yellow. If anything looks dark or burnt, have it flushed and replaced right away.



  6. Viva la Difference

    Full-synthetic motor oil

    Full synthetic motor oil contains base oil that is man-made. The synthesis processes through which the oil is made improve key performance attributes and enable improvements to wear protection, extreme temperature performance and deposit control. It also provides an opportunity for lower viscosity grades (like 0W-20) that are designed to improve fuel economy.

    Part-synthetic (synthetic blend) motor oil

    Part-synthetic—also called synthetic blend or semi-synthetic—oils are blends of mineral oil (conventional) and synthetic base oil. Part-synthetic motor oil is designed to have some of the benefits of a full synthetic but at a lower cost.


    The number of OEMs (Original Equipment Manufacturers) whose specifications require the use of full synthetic or part synthetic engine oils began increasing several years ago. The latest data indicates that 45% of all cars, SUVs and light trucks sold in 2012 had an OEM requirement that a full or part synthetic motor oil be used. For cars alone, it was 57% for 2012 model year vehicles.

    The increase in synthetic oil use can be attributed to:

    1. Corporate average fuel economy (CAFE) standards that drive the need for lower-viscosity engine oils that require synthetic base oil formulas.
    2. OEM recommendations for longer drain intervals and the desire to protect the engine under warranty.
    3. More power-intense engines that benefit from the protection of synthetic engine oil.



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