It's no secret fuel costs are high and that has many people and companies trying to find ways to save money. There's also been a push towards going green, so how can trucking companies, save cash while helping the environment too?

Semis are the work horses of the road but the Environmental Protection Agency says heavy duty trucks are also a major source of air pollution. The Department of Commerce started a grant program to help put in more efficient equipment, but its only got $1 million to give and more than $6 million in requests.

An A.P.U. is “an auxiliary power unit" says Marten Transport Maintenance Administration Manager Ed Accola.

An A.P.U. can help keep truck drivers warm, cool and powered up even when the semi is shut off.

"It really adds up to a lot of fuel saved in the short term and in the long run the reduction of pollutants and things like that that have a lasting impact on the environment" says Accola.

Accola says Marten is retrofitting its entire fleet. That's more than 2,000 trucks.

He says "we’re at about 1,000 right now. We expect to have over 1,200 done by the end of the year."

The Environmental Protection Agency is honoring Marten Transport for its effort. The company is doing it without government help and it’s not cheap.

"$16 million" says Accola.

That's between $8,000.00 and $8,500.00 per A.P.U but Accola says with the amount of money they are saving an A.P.U will have paid for itself in about 18 months."

Accola says "we're roughly 4-million gallons of fuel saved for 2009 as a calendar year."

And truck drivers NewsCenter 13 talked to love them. That's because some towns don’t allow trucks to idle at all but with an A.P.U the driver can catch a nap comfortably.

Accola says "they'd just be sitting there sweating or freezing or whatever the case may be."

"It keeps the truck warm and I’m saving fuel at the same time" and driver Brian Rager says the smaller engines are much quieter.

"I have a hard time sleeping when the truck's idling" says Rager.

Accola says one A.P.U. can take about 10 hours to install. He expects all Marten trucks to be finished in about a year. The Wisconsin Department of Commerce told NewsCenter 13 Monday, its grant program is so popular, it's having to turn drivers away. There's no word on if there will be more state money available.