The following video is part of our "Motley Fool Conversations" series, in which industrials editor/analyst Isaac Pino discusses topics around the investing world.

In today's edition, Isaac sounds off on yet another exciting announcement from one of the leading manufacturers of natural gas conversion engines, Westport Innovations. For investors bullish on natural gas as a transportation fuel, the news of Westport's second agreement with General Motors could provide a catalyst for the entire industry. The deal pushes natural gas technologies into a more mainstream consumer segment through light-duty vehicles such as sedans, pickup trucks, and SUVs. Not surprisingly, the announcement sparked a rally in Westport's stock, up 9.2% at the market close. Likewise, Clean Energy Fuels, a leader in building out natural gas fueling stations, jumped 2.2% on the positive natty gas news.

From Isaac's perspective, Westport and Clean Energy offer tremendous growth opportunities but remain speculative stocks for unprofitable companies. For investors interested in steadier returns over the long haul, uncover a more surefire energy stock in our special free report: "The Only Energy Stock You'll Ever Need." Don't miss out on this limited-time offer and your opportunity to discover this under-the-radar company before the market does. Click here to access your report -- it's totally free.

Isaac Pino has no positions in the stocks mentioned above. The Motley Fool owns shares of Ford and Westport Innovations. Motley Fool newsletter services recommend Clean Energy Fuels, Ford, General Motors, and Westport Innovations. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.