Ahhh, oil! Black gold. Texas tea. At least that’s how the opening to the television show Beverly Hillbillies referred to it. (Anyone else besides me remember black and white TV?) While some folks will tell you that there’s nothing new under the sun, I can say with certainty that there has been much happening and I’ve been evaluating all sorts of new products to lubricate your internal combustion engines. So, not surprisingly with that lead in, this month we’re going to talk a little about motor oils, their classifications, and some little-known factoids of the latest and greatest developments.

Motor Oil Standards

There are three domestic nonprofit trade groups that are involved in the lubrication specification business, and you’re likely to see any or all of their initials on the next bottle of oil you buy. The American Petroleum Institute (API), Society of Automotive Engineers (SAE), and the American Society of Testing and Materials (ASTM) joined efforts with the American Automobile Manufacturers Association (the U.S.’s “big three” auto manufacturers) to develop standards for engine oils. To measure those, they developed lab and operational tests to allow oil manufacturers to certify that their products met a range of performance criteria. There is a crazy-complex system of ratings, but here’s a short list of just some of the properties for which commercial oils have to be tested and certified. Some you’d expect; others seem very obscure. For example:

  • Viscosity, Fresh and Aged: This measures what you might call the thickness of the oil — right from the factory and after it has been in storage under different temperature conditions.
  • Volatility: This measures the rate at which the oil evaporates under operating conditions.
  • Gelation: This measures the apparent thickness of the oil as temperature drops. This might not be a big deal to residents of Texas or Florida, but operations in Maine, Alaska, or North Dakota probably have to start sluggish winter engines.
  • Wear, Sludge, and Varnish: These tests run an engine under controlled conditions for a set period of time. After the simulation run, the engine is dismantled, the components are closely examined for deposits, and wear of internal components is measured.
  • Valvetrain Wear: Again, a specific type and model of engine is run under controlled conditions for a set period of time, and the valvetrain components are measured to detect wear.
  • Fuel Efficiency: An engine is loaded with the oil being tested, taken through six different test speeds for a certain amount of time, and then the fuel consumption is measured.

Would you believe that there are more than twenty-four different tests that define different properties of the oil? The testing group decides what the minimum criteria is for each property, and that standard becomes the automobile manufacturers’ standard. The key here is that the API service seal sets the minimum standards for the product that you’re buying. It looks like a ring with some letters in the middle. We’re going to talk about what those letters and numbers mean next.


Did you ever wonder what the alphabet soup means on the outside of the oil bottle? My good friend and camp facilities veteran, Doug Guthrie, who’s now an ASE-certified automotive vocational technical teacher, taught me these things. The top of the API seal says “API Service __” — with the blank being a two-letter code. This indicates the type of detergent combination that the manufacturer included. “S” codes apply to gasoline engines and “C” codes are for diesels. The second letter comes over time as new levels of protection are developed. For example, “F” is newer than, and presumably better than, “E.” So an oil intended for gasoline engines with the latest detergents might begin “SF.”

The next packet of code, located in the middle of the seal, refers to the oil’s weight. Sometimes it is a number just by itself, such as “30,” which stands for “30-weight oil.” The lower the number, the thinner the oil. When there are two numbers separated by a letter (usually a “W,” for “winter”), it is a multi-viscosity oil. The two numbers refer to different apparent viscosities depending on the oil’s temperature. In the case of 10W-40, the oil behaves like a 10-weight oil, but when it’s hot it behaves like a 40-weight oil. This is very, very helpful when starting engines in the cold because the starter doesn’t have to work against thick oil AND low cranking amps. The lower the first number preceding the W, the better the oil’s cold starting performance. When the engine and oil come up to normal operating temperature, it is providing all of the friction-busting slickness that a 40- weight would. This very helpful behavior is brought about by adding chemicals to the oil (“detergents”) whose performance has been known to decrease over time. So in some ways, it’s even more important to change multi-viscosity oil promptly than it is to change it in the summertime. Finally, there are oils that are simply a number preceded by HD (meaning “heavy detergent”), or with no letters at all, which means that it contains no detergents at all.

And the great part about this labeling system is that it applies to both petroleum- based and synthetic oils because it’s all about the API certifications, standards, and tests.

Green Motor Oil?

Now here’s something very cool that you won’t find anywhere else. The camp community is always looking for ways to be more earth friendly — in a word, “greener.” Two years ago, I encountered Glenn Johnson of AutoBeGreen at the Camp Maintenance Conference at YMCA Camp Chingachgook in Upstate New York. (It happens every year at this location on Lake George in March, and it has received Educational Endorsement from ACA. You should go!) Glenn’s company sells fully biodegradable motor oils that bear the API seal. According to his Web site, a 5.1-quart jug of 10W-30 is about $36. (There are coupons and volume discounts available, I’m told.) So while that’s a bit more than is conventional, it is very competitive with its synthetic but non-biodegradable counterparts. Why not get on board with the “green” movement and, while still doing your part to manage the waste oil properly, not worry about spills that could impair streams and lakes? AutoBeGreen sells a range of environmentally friendly motor vehicle products as well.

Which Oil Do I Use?

Now that you know what those numbers and letters mean, and since the API seal sets the standard, you can peruse the shelves at the local big box store with confidence. Or can you? How do you know which multi-viscosity oil is the one for your equipment? This is the ugly part. Really. And being the kind of free spirits that camp folks are, it’s going to grate on some of your nerves. But it’s true: Read. Read the manual. Read the sticker on the inside of the hood. Look up the vehicle and read it on the Internet. The engineers who designed your vehicle (mower, tractor, car, boat, whatever) designed the motor’s innards to use oil with very specific properties. I promise that none of us is smarter than the engineer who made those decisions a long time ago. Don’t try to outthink him, and don’t let “Quik-Lube” tell you different, either. Insist on using the oil that’s specified in the manual that goes with each vehicle. Coloring outside of these lines will bring consequences: The best thing that may happen is that your fuel economy will tank. The worst thing that could happen is that you ruin the engine from using oil that’s too thin (and doesn’t lubricate even though it’s present) or too thick (and can’t get to the parts to lubricate them).

This is just one of the dozens of useful things that you could learn at the Camp Maintenance Conference. And not to leave out the other important support staff function, the Camp Food Service Conference happens at that same facility the week prior. Why not reach out to conference organizers Carol Lewis, George Painter, and Billy Rankin (visit www.campmaintenance.com) and make plans to attend this year’s gathering, March 25–27, 2014? Take just a few days out of the pre-spring preparations to grow your brain, hone some skills, and connect with other like-minded professionals in your field on beautiful Lake George. You’ll be glad that you did!

Rick Stryker is a professional engineer with a particular passion for helping camps with infrastructure, planning, and regulatory issues. He can always be reached at campfc@ptd.net or 570.828.4004.

Originally published in the 2014 January/February Camping Magazine