In 2012, the United States consumed almost 8.7 million barrels of gasoline per day and 3.7 million barrels of distillate fuels, most of them used in transportation, according to the U.S. Energy Information Administration.

Much of that diesel fuel was used in trucks, locomotives and high horsepower industrial engines, where its market share is now threatened by LNG and CNG.

The equipment needed to compress and liquefy natural gas, dispense it safely, store it on board, and use it in dual-fuel engines is being rapidly developed and installed across North America.

LNG as a transport fuel enjoys powerful backing from petroleum producers like Shell as well as major manufacturers and suppliers like Caterpillar and GE and oilfield services companies like Schlumberger and Baker Hughes.

The fuel market appears to be nearing a tipping point. If the present gap between natural gas and crude oil prices remains for another 2-3 years, it should be enough for natural gas to establish a major beach-head in the transport market, pitting crude oil in direct competition with natural gas.

Eoin Treacy's view A fact often overlooked when considering the outlook for major oil companies is that both Exxon Mobil and Royal Dutch Shell produce more natural gas than oil. Therefore they have a vested interest in securing new customers and markets for their products.

High oil prices encouraged a supply response in unconventional resources which has since yielded substantial dividends for the USA. However, the high price environment in the rest of the world has also created an opportunity for investment in unconventional supply and substitution by natural gas.

While the USA will export natural gas in 2015 at the earliest, the export of technology relating to increasing the use of natural gas as a transportation fuel is already occurring and represents an equally important bull market.

Cummins is a leader in the development of diesel and natural gas engines. The share broke out of a two-year range in August and found support last week in the region of the 200-day MA. A sustained move below $120 would now be required to question medium-term scope for additional upside.

Worthington Industries focuses on precision steel products. Its pressure cylinders division is its fastest growing and represented a third of revenues by May. The share completed a decade long base in December 2012 and continues to extend the medium-term uptrend. It has surged higher over the last month and is becoming increasingly susceptible to mean reversion.