SANTA MONICA, Calif. — During this time of year, when the auto market is in the midst of a traditionally slow season and automakers are less apt to offer incentives, dealers are often more inclined to include discounts to help spur sales, according to TrueCar.

In light of this environment, TrueCar, as part of its monthly TrueTrends Report, announced the top 2009 and 2010 vehicles with the heaviest discounts, and showing a dominant presence on both lists were Big 3 brands.

Specifically, three Chevrolet models (Cobalt, Silverado 1500, and Corvette) were among the five models listed on the Top 2009 Greatest Discounted Models, a list that the Dodge Ram 1500 topped with an average discount of 27 percent.

The Kia Sorrento was No. 2 with a 23-percent discount, while the Cobalt was No. 3 (20 percent) and the Silverado 1500 and Corvette (17 percent) were tied for fourth.

Meanwhile, on the list of Top 2010 Greatest Discounted Models, three of the five vehicles were from Ford, including the Ranger, which led the way with a 17-percent discount.

The Edge was tied for third with a 13 percent discount (tying with the Toyota Tundra 2WD), while the Focus had the fifth-highest discount at 12 percent. Another domestic on the list was the Jeep Grand Cherokee, whose 16-percent average discount put it second.

"January is historically a very slow month for dealerships in terms of sales," said Jesse Toprak, vice president of industry, trends and insights for TrueCar.com. "The manufacturers typically offer fewer incentives to consumers so the dealers are much more willing to offer discounts off of MSRP to help make more deals."

He added: "So January could actually turn out to be a really great month for consumers who do their homework before they buy, as dealers are more motivated to make something from nothing."

The complete top five lists are as follows:

Top 2009 Greatest Discounted Models  

1. Dodge Ram 1500, 27 percent       

2. Kia Sorrento, 23 percent       

3. Chevrolet Cobalt, 20 percent      

4. Chevrolet Silverado 1500, 17 percent      

5. Chevrolet Corvette, 17 percent     

Top 2010 Greatest Discounted Models

1. Ford Ranger, 17 percent

2. Jeep Grand Cherokee, 16 percent

3. Toyota Tundra 2WD, 13 percent

4. Ford Edge, 13 percent

5. Ford Focus, 12 percent

Moving on, TrueCar also unveiled in the report the Most Flexible Vehicles 2009 and 2010 models, which are calculated by its Price Flex Score. This considers various elements that can impact price variance, officials noted, such as transaction price range, current inventory and sales data.

Based on these scores, the most flexible 2010 model is the Chrysler PT-Cruiser with a score of 93, followed by the Mazda MX-5 Miata (90), Mazda 6 (88), Hummer H3 (86) and the Hyundai Accent (85).

For 2009 models, the H3 and MX-5 Miata were the most flexible, as both had scores of 97. The Dodge Viper was next (91), with the Volkswagen New Beetle (90) and Volkswagen EOS (89) rounding out the top five.

Moving on, TrueCar also unveiled what it has calculated to be the best day to buy a vehicle in the next 31 days. According to its data, Feb. 1 is the top day. TrueCar expects discounts to be 6.62 percent.

However, Jan. 25 and Feb. 8 are also projected to have discounts of more than 6.5 percent. Meanwhile, the lowest day for discounts is expected to be Feb. 9, when the average is projected at 5.42 percent. 

Next, TrueCar looked at what new vehicles are staying in dealers' inventories for the longest and shortest periods of time. 

For 2009 models, the Acura MDX has had the shortest days on the lot, averaging 27. Meanwhile, the Saab 9-3, on average, has sat on the lot 358 days. 

"Apparently, fears of becoming an orphan owner have kept consumers away from the Saab, with the 2009 9-3 averaging nearly a year in inventory," officials explained. 

Meanwhile, among 2010 units, the Lexus GX 460 ranks at the top of fastest turn rates, as it typically spends only five days on the lot, according to TrueCar. The Kia Forte has the longest time in inventory, averaging 72 days, officials added.