While cost isn’t the only driving factor behind choosing a hybrid vehicle, consumers do look at the purchase price and long-term operating costs when researching hybrids. Often times this cost efficiency analysis comes down to the price difference between the non-hybrid version of a vehicle or the hybrid. A recent analysis of hybrid vehicles conducted by the British Columbia Automobile Association (BCAA) reveals that the most cost-efficient hybrid is the Mercedes-Benz S400.

It is important to define cost-efficiency in this case. The study compared hybrid vehicles with their non-hybrid counterparts and looked at which was less expensive over a five-year time period. The only hybrid vehicle that was less expensive at the five-year mark was the Mercedes-Benz S400.

The price tag of the S400 Hybrid is $105,900 and its conventional counterpart, the Mercedes-Benz S450 has an MSRP of $108,000. At the end of five years, the cost of ownership for the S400 Hybrid was $145,265 while the S450 was $150,622. Even when you take into account the initial savings with the S400, the hybrid model was less expensive to own and operate than its conventional counterpart. However, it is difficult to consider a $100,000+ vehicle as cost-efficient.

Two Honda models came in right behind the Mercedes-Benz S400 Hybrid: the Honda Civic Hybrid and the Honda Insight. The Civic Hybrid has a total five-year cost of ownership that is $290 more than the conventional counterpart and the Insight’s premium costs were only $1,172.

Although the Honda Civic Hybrid and the Honda Insight have a lower five-year cost of ownership than the Toyota Prius, there are still fewer sales of these two models, combined, then there are of the Prius. In July 2010, Honda sold a total of 2,475 Insights and Civic Hybrids while Toyota sold more than 14,000 Priuses.

The Lexus HS 250h was the only other hybrid model that had a five-year cost of ownership that was less than $2,000 more than the non-hybrid counterpart, in this case the Lexus IS 250.

While upfront costs as well as long-term operating expenditures are part of the hybrid car buying process, consumers should really consider the environmental impact of a hybrid vehicle as the primary factor when choosing a hybrid over a conventional vehicle.

In looking at the environmental benefits, alone, the Toyota Prius comes out on top. The Prius emits 55 percent less greenhouse gas emissions than its conventional cousin the Toyota Matrix XR. The Ford Fusion Hybrid squeaks into this list in the number two spot with a 38 percent reduction in greenhouse gas emissions. Just behind Ford is the Honda Civic Hybrid with a 37 percent reduction in tailpipe emissions.

For more information on other hybrid models, download the BCAA’s 5-Year Hybrid Vehicle Cost Analysis (PDF) report.