Green trucks were everywhere at this year's Work Truck Show, especially big trucks.

Move over, Chevy Volt. The hulking F-750 that Ford displayed in its booth featured a parallel-hybrid drive built by Odyne Systems LLC and carried a 28.4 kWh lithium-ion Johnson Controls battery pack. The 74-hp electric motor provides launch assist, amplifies power and torque at cruising speeds and saves up to 1,750 gallons of fuel annually, Odyne says.

The diesel and electric plug-in hybrid drive costs about $85,000 extra and takes about five hours to charge up. But when used on a bucket truck, crane or digger derrick, it can effectively double fuel economy, says Odyne. When you only get around 3 mpg on a conventional truck of this type, any efficiency boost is a big one.

Natural gas was a hot topic. As I reported at the beginning of the show, U.S. Dept. of Energy Secretary Steven Chu called upon commercial truckers to switch to natural gas, which can run in gasoline or diesel engines with minor modifications.

Chrysler, Ford and General Motors met the call by exhibiting new three-quarter-ton "bi-fuel" pickups that handle gasoline or compressed natural gas. Not everyone is sold on the idea, but many fleet owners are looking seriously at this new breed of pickup to hedge against the rising price of oil. We'll have a full review of these trucks coming soon in ENR.

Some even got a chance to the drive the green giants on display.

In a Green Truck Ride-and-Drive behind the Indiana Convention Center, BAE Systems offered attendees a chance to drive its new hybrid-electric powertrain, built in partnership with Caterpillar, on a Class 8 Kenworth T-800 dump truck. Lightning Hybrids Inc. displayed a Chevrolet 3500 cutaway van that used hydraulic fluid to save energy.

I drove a Ram 2500 Heavy Duty CNG pickup around a short loop in downtown Indianapolis. It starts on gasoline (CNG does not burn well at a cold start) then switches to CNG. I was surprised how seamlessly the changeover was.

I also drove a Ford F-150 equipped with a Roush propane conversion. Like the Ram, unladen, it drove no differently from the gasoline-only model.

Driving aside, you notice the size of the tanks in these CNG and propane trucks. They take up space (between two and three feet of the length of a pickup bed) and carry a weight penalty. But with the price of natural gas saving between $1.50 and $2 per equivalent gallon, some fleet owners are pushing pencil to paper to see if they can get a reasonable payback.

Recall last year's story, in which I rode along in a Class-8 concrete mixer running exclusively on CNG. The owner of that fleet added a baker's dozen after pilot-testing the first one.

Have you had experience running alternative fuels in your own fleet? Tell us about it in the comments below.