New particulate filters made from ceramic and developed by Geo2 Technologies could increase fuel efficiency while reducing the amount of soot emitted by diesel engines.

Geo2 Technologies' VP of product development Bilal Zuberi told me the technology his company is developing could filter out multiple pollutants simultaneously in a much smaller package. Zuberi says the technology can filter out both nitrogen oxide and other emissions, saving valuable space and weight in a vehicle, enhancing fuel efficiency. Geo2's goal is reduce the size of today's particulate filters by 1/2 to 2/3.

Particulate filters can reduce the fuel efficiency of vehicles because of building up "backpressure" when the flow of gases becomes to slow, according to Zuberi. Geo2's filters are more porous, and will only increase backpressure by 4 percent. The filters will also remove up to 95 percent of the soot, he said.

The ceramic material costs about as much as today's powder-based filters, Zuberi says, but they cost less because they do not require the precious metals such as platinum that make up several hundred dollars of the price. (CORRECTION: Geo2' diesel particulate filters do not require precious metals, while their multi-function filters use less precious metals than current products.) The technology, which is currently being evaluated by a tier one supplier and OEMs according to Zuberi, could show up in production vehicles as early as 2010.

Companies that have not invested in (or perhaps believe in) hybrid technology are planning a slew of diesel vehicles in the next few years as high MPG alternatives. If this technology works as planned, diesels good surpass hybrids in both fuel economy and emissions.