The Toronto Transit Commission is reconsidering ordering more diesel/battery hybrid buses as they're performing at less than 20 percent of capacity.

The Daimler buses are supposed to have a five-year battery life but the TTC says the batteries are depleting after just 18 months, the Toronto Star reported. In addition, diesel fuel savings have been only one-third of projections, the TTC board was told.

Thursday, the commission voted to delay ordering another 120 of the hybrids and investigate a return to diesel buses manufactured by the New Flyer company, the report said.

TTC General Manager Gary Webster told the Star buying diesel buses in 2010 would save about $24 million initially as each hybrid costs about $200,000 more than a diesel.

However, the commission said it also wants to explore using Daimler's new lithium-ion batteries to see if they are more reliable than the existing lead-acid models, the report said.

Toronto's decision to purchase the first hybrids was based on New York City's experience, the Star said. However, buses there face much more stop-and-go traffic, which is where the batteries make for better fuel efficiency, the report said.