Gasoline-electric hybrids are losing their competitive edge over ther gasoline counterparts due to falling fuel prices and more efficient internal combustion engines, according to a five-year owner cost analysis by Vincentric.

The research firm studied the total cost of owning a hybrid, and found that 10 of the 31 hybrids included in the research were more cost-effective to own that their gasoline counterpart. The percentage of cost-effective hybrids has fallen to 32 percent from 39 percent in the 2013 study and 44 percent in the 2012 study.

The Lexus CT200h and the Toyota Avalon Hybrid returned impressive lower ownership costs with savings of over $7,600 and $3,200 respectively. Additional hybrids from Acura, Audi, Honda, Hyundai, Lexus, Lincoln, and Toyota also showed cost advantages, according to Vincentric.

However, when the costs to own and operate all 31 hybrid vehicles were taken into account, the average five-year cost-of-ownership for hybrids was $1,339 more than their gasoline-powered counterparts.

“In some cases, fuel cost savings associated with hybrid vehicles are able to offset their price premium. However, hybrids are losing their competitive edge due to the improved fuel economy of gas-powered combustion engines and falling fuel prices,” stated David Wurster, Vincentric's president. “Consumers must look at individual models to determine whether a hybrid or its gas-powered counterpart has lower ownership costs and will save them money in the long run."

Vincentric measured total cost-of-ownership using eight different cost factors: depreciation, fees & taxes, financing, fuel, insurance, maintenance, opportunity cost, and repairs. The analysis assumed vehicle ownership of five years and 15,000 annual miles of driving.

Here's the list of the top 10 models:

• 2014 Acura ILX Hybrid ($1,613)

• 2014 Audi Q5 Hybrid ($2,611)

• 2014 Honda Insight ($86)

• 2014 Hyundai Sonata Hybrid ($1,379)

• 2014 Infiniti QX60 Hybrid ($191)

• 2014 Lexus CT 200h ($7,632)

• 2014 Lexus ES 300h ($1,179)

• 2014 Lincoln MKZ Hybrid ($3,252)

• 2014 Toyota Avalon Hybrid ($3,356)

• 2014 Toyota Camry 2014.5 Hybrid ($1,075)