Nearly half of the diesel vehicles analyzed in Vincentric's 2013 Diesel Cost-of-Ownership Analysis have a lower total cost-of-ownership than their gasoline powered counterparts, the firm reported Wednesday.

Of the 26 diesel vehicles studied, 12 bested gasoline-fueled counterparts. The finding represented an 11.4% increase in cost-effective diesels from the firm's 2012 study, in which only eight of 23 vehicles showed a cost advantage.

The 12 diesel vehicles with lower ownership costs included all four Mercedes-Benz diesel models measured, along with the Audi A3 sedan, BMW X5 crossover, Ford F-350 truck, GMC Sierra 3500 truck, and four of five Volkswagen diesel models. The average price premium for a diesel was $5,392, with average fuel cost savings of $2,117.

When all costs to own and operate a diesel were taken into account, the average cost-of-ownership for diesels was $1,017 more than their all-gasoline powered counterparts, up $266 from the previous year, with results assuming an annual mileage of 15,000 over five years.

Vincentric measures eight cost elements for over 3,000 vehicles configurations per model year, including depreciation, financing, fees and taxes, fuel, insurance, maintenance, opportunity cost and repairs. Each month Vincentric re-compiles its database to take into account current vehicle prices, resale values, fuel costs, finance rates and other economic and market factors to ensure that users have access to up-to-date and accurate ownership costs.

Vincentric is an automotive research firm specializing in lifecycle cost measurement. Get more information about the report here.