But something changed. The shorthand for it sounds vaguely like an impolite term, but it isnt. The term is fracking, for hydraulic fracturing, and it represents a technique for oil and gas production which seems almost too good to be true. It turns out that fracking has made almost anywhere in the country a potential source of hydrocarbons (unlike vertical drilling which is strictly hit-or-miss). Fracking is so effective that some industry experts are saying that by 2020 the United States will be the repository of the largest oil and gas reserves in the world.

Fracking has made North Dakota the state with the lowest unemployment in the country. In Williston, N.D., smack dab in the middle of the Bakken oil fields, jobs at McDonalds are paying $18,000 per year – 25 percent over minimum wage – because hiring is so competitive. Rents have doubled in less than two years, and thousands of oil field workers are living in trailer camps. Boomtowns are popping up and many oil exploration and production professionals are heading north.

There are similar opportunities for fracking in Texas, Pennsylvania, New York and California. The only things standing in the way at some locations are state regulations, which need to catch up with what is happening underground, and some public understanding that fracking is a good thing and is not destroying the environment.

As many of you know, I like to read the Wall Street Journal, especially the weekend editions Review section. One of the best columns is by Matt Ridley, the Rational Optimist, whom I always find provocative and educational. His June 8 piece, Non-fossil Fuels, can be found at www.rationaloptimist.com. Its worth a read by everyone, and discusses some unusual thinking about the source of natural gas.

When oil was first discovered, Ridley notes, two main theories were proposed about its origins. Generally speaking, there was the fossil theory which suggested that crude oil came from ancient life-forms. This conjures up images of dinosaurs dying in swamps and deserts, a la Fantasia, or a much larger source of organic material, plant life that flourished and ultimately became the pools of crude. Of course this is nonrenewable, stored energy, extracted from prehistoric sunlight. The U.S. oil industry supported this idea and its been very successful at guiding oil exploration, so the fossil theory has been the dominant one for some time.

But there are those who doubt whether all natural gas – which is 90 percent methane – comes from fermented fossil microbes. Some of it, per this theory, may be made by chemical processes deep within the earth. If thats true, there could be some major changes for the climate and energy debates. One of the early champions of this view, which is commonly called the abiogenic or outgassing theory, was Dmitri Mendeleev, who was a pretty smart guy. (Hes the Russian chemist who figured out the modern periodic table of the elements.)

Why would there be so much natural gas in so many places if fossils were the sole source of these hydrocarbons? Maybe there is some validity to the outgassing theory. Rather than quoting the whole article, I suggest that you read it for yourself and see what you think.

Well, thats enough geology for this column. What Im really getting at is that natural gas can become an abundant fuel source for vehicles, beyond whats happening in that area currently. The graph on page 10 shows the number of natural gas fueled vehicles worldwide and how it has grown over the last 20 years. Needless to say, North America is way behind on this one. Outside of some vocational trucks and city bus fleets, weve never felt the need before now. However, the cost of natural gas is getting to the point where it is becoming an attractive alternative to gasoline, and its so readily available that we would be foolish not to consider it.

Before getting to vehicles, Ill add just a brief reminder that natural gas engines have been around for a long time in stationary applications. Anywhere you can tap into natural gas, theres an opportunity to use it as fuel. Some prime examples are auxiliary engines used to generate electricity for vital services such as hospitals. Many engines in pumping service for crude oil or water are natural gas fueled. Offshore drilling operations use natural gas to power most of their needs for electricity, either in internal combustion engines or gas turbines. There also are dual-fueled industrial engines, able to nimbly switch between diesel and natural gas whenever one is more cheaply available, co-generation plants that burn the gas that seeps up from landfills and biomass piles, and peaking-power generators that kick on when electric utilities see spikes in demand.

Natural gas, either compressed (CNG) or liquefied (LNG), has been used in vehicles for years, too. When I was with Pennzoil, back in the day, we often fielded requests for engine lubricant recommendations for vehicles that had been converted from carburetors to gaseous fuels. We normally recommended a regular engine oil with extra zinc additives, since those retrofitted engines still had all of the conventional engine hardware. A major concern was wear, and the oils of that time carried what is by todays standards a heavy load of zinc dialkylthiophosphate anti-wear component.

There are now numerous conversion kits available and even first-intent natural gas engines on the market, notably from Westport Innovations and its Cummins Westport joint venture. For a number of years, passenger cars could be equipped only through aftermarket conversions to natural gas, but Honda today offers a first-intent natural gas (CNG) version of the 2013 Civic, currently the only automobile available in the United States with this option.

Other OEMs including Ford, GMC and Chevrolet offer turn-key natural gas retrofits for some of their trucks and vans, as well.

However, there are a number of vehicle applications where natural gas is used as a first-intent fuel. One of these is forklifts running inside warehouses, where natural gas fuel is preferred for safety reasons. Another is bus fleets and refuse trucks, which got into the natural gas fuel arena in a big way to cut emissions, as the exhaust from burning natural gas is not as noxious as diesel exhaust. In addition, it is pretty easy to set up a central CNG fueling station for such fleets. Some delivery fleets used in intracity service have also moved to natural gas fueled vehicles. A Ryder fleet in southern California recently announced plans to convert 300 vehicles to CNG service, for example.

Other new transportation areas where natural gas fuel is making inroads include railroad locomotives and marine applications.

With the pressure on vehicle manufacturers to improve both fuel economy and emissions, CNG and LNG are seeing renewed scrutiny. For instance, the octane number of methane is about 120, which allows for higher compression ratios and more power per liter of engine displacement. Natural gas, whether CNG or LNG, burns cleaner than diesel or gasoline, which means lower emissions. At the present time, natural gas is cheaper than the gasoline or diesel energy equivalent.

There are downsides though, such as the need for a physically larger tank – up to 3.5 times the size – to hold enough CNG or LNG to match the cruising range of a diesel or gasoline vehicle. Next time you see a city bus boasting it runs on clean gas, take a glance at its roof to get an idea of the territory these tanks require.

Second, the fuel system must be manufactured from higher strength parts due to the pressures required to fill gas into the cylinders. That adds weight, of course, and cost. Third, and critically, there is also the small problem of having no U.S. fuel distribution system in place to service vehicles adequately and conveniently.

Finally, a heavy-duty natural gas vehicle can cost $30,000 to $70,000 more than one with a conventional powerplant, depending on size and other factors, and it can take years to recoup this added investment.

So how to lubricate these engines? As I mentioned earlier, motor oil sellers in the past might have based their recommendations for gas-converted engines on the fact that the engine was the same basic design. However, that was probably overkill in some regards. For instance, because natural gas burns so cleanly, the need for dispersants to suspend sludge and varnish precursors is reduced. There is also less need for TBN since there are fewer contaminants to generate acidic materials in the exhaust blowby.

However, natural gas engines do run hotter so the need for antioxidants is increased. The oils used in stationary gas engines are typically lower in sulfated ash and antiwear but higher in antioxidants – and the same can be true for natural gas vehicle engine oils. The table on page 10 compares typical natural gas engine oils to their gasoline and diesel counterparts.

One thing to note is that natural gas engine oils can be of many different compositions. Thats because gas engine oils are formulated to meet each specific engine manufacturers requirements. Youll not find the familiar API donut or engine oil licensing system here. While heavy-duty and light-duty OEMs may prefer a generic standard for conventional gasoline and diesel engine oils. They have their own standards for natural gas engines.

Cummins Westport, for example, requires natural gas engine oil meeting the Cummins specification CES20074. It includes a sulfated ash limit of 0.6 percent, because higher ash oils can cause valve or piston damage. Use of other oils may lead to excessive oil consumption and degradation of the catalyst, Cummins Westpoint warns.

This month is to see the start up of full production of Cummins Westports 12-liter ISX 12 G engine, which should become available on trucks from Freightliner, Kenworth, Mack, Peterbilt and others. Drain intervals have been set at 18,000 miles or 400 hours of service when the duty cycle averages 45 mph, and less for slower average speeds.

International Truck is working on a natural gas version of its MaxxForce engine for long-haul trucking, and last year began offering bus and vocational truck operators an ISL G engine from Cummins Westport. This 8.9 liter engine also takes oil meeting the CES20074 spec, with drain intervals set at 7,500 miles/500 hours for buses and refuse trucks and 15,000 miles/500 hours in Class 7/8 trucks.

Where will these trucks get their fuel? Thats still the big question. There are only about 1,200 natural gas fueling stations across the country. Compare that to more than 118,000 service stations selling gasoline and 32,000 pumping diesel, and its no surprise the entire U.S. natural gas vehicle fleet numbers only about 150,000 units.

So yes, its slow going right now, but its also the beginning of the beginning, not the beginning of the end as some feared 20 years ago. At any rate, there is pretty clear evidence that natural gas will be used in a lot of applications and definitely has a place in your motoring future – and in your motor oil lineup.