We see more hybrid cars on the road, but one Savannah trolley company is using propane gas to power part of its fleet, saving money and energy. Old Town Trolley Tours got its first propane trolley seven years ago, now they are up to four and they soon hope to convert all 23 trolleys to propane gas. People getting on one of the propane-powered trolleys didn't realize they were being driven around on propane gas, until we told them. "I think it's great," said tourist Calvin Jones. Once we pointed it out, they did notice some differences between this trolley and a diesel-fueled one. "I know diesel, it stinks and smokes a lot," said Susan Fowler. Her husband, Jeff Fowler, added, "And the sound too, there was a diesel next to us and when it started up it was awful loud."