"It's got an electric drive with a diesel engine, and one of the neat things we are finding is the fuel consumption is a lot less, somewhere in the order of 10 to 20 percent," said Dr. Kent Johnson, a professor of engineering at the University of California at Riverside.
Johnson said results also show the experimental hybrid emits 99 percent less pollution.
"We won a $2 million grant," he said. "The first million was to help deploy hybrid equipment in the state and the second was to evaluate it."
The job of evaluating was not an easy task. It required months of field testing. Engineering graduate student Sam Coa spent hours monitoring data from a portable emissions system on top of the bulldozer.
"We're able to do real-world emissions testing inside a landfill where before it was impossible," Coa said.
Waste Management, which operates the landfill, said the experiment falls in line with its goal of reducing emissions and increasing fuel efficiency.
"It means that we will be investing in more equipment in the near future in many of our other landfills," said Lily Quiroa, a spokeswoman for Waste Management.
Waste Management said it's so impressed with hybrid bulldozers that it already put in a purchase for 14 of them. The company plans on spreading them out across its landfills nationwide.