Toyota posts a double-digit sales gain in March on the strength of its core passenger-car offerings, as U.S consumers start seeking relief from rising gasoline prices.

The Japanese auto maker delivers 203,282 cars and trucks in March, up 11.2% from year-ago on a daily selling rate basis, according to WardsAuto data. There were 28 selling days last month and 27 year-ago.

It was the best March for Toyota since 2008 and the best month overall for the auto maker since Cash for Clunkers in August 2009.

Toyota spent most of last year rebuilding its inventories after Japan’s devastating earthquake and tsunami that choked off its parts-supply lines and slowed sales rates.

The auto maker showed new vigor in March, with the Camry, Prius and Corolla paving the way. Camry sales jumped 19.4% to 37,163 units, excluding 5,404 deliveries of its hybrid model.

Prius hybrid deliveries soared 48.8% to 28,711 units as its broadened number of variants caught more car buyers’ attention. The Prius also set a new quarterly mark with more than 60,000 units sold in the year’s first three months.

“The (high) cost of fuel has had a positive impact on consumer demand for (the) Prius,” Jeff Bracken, vice president-sales Toyota Div., tells WardsAuto in a conference call to discuss the March results.

The American Automobile Assn. says prices for a gallon of regular gasoline rose to nearly $4 per gallon in March, up more than $0.40 from year-ago. Experts speculate the run-up at the pump will continue into the summer.

Bracken says Toyota enters April with a “healthy supply” of its three Prius variants, or about 23,000 units of inventory for 22 days’ supply. The industry typically likes to carry a 60 days’ supply of individual models.

Toyota struggled to meet demand for the Prius in particular last year after the natural disaster and is just catching up on inventories. The Prius range grows this year from the pioneering liftback model to the low-cost Prius C and Prius V multipurpose vehicle.  “The new models are bringing new buyers into the Prius family,” Bracken says.

The Corolla provided Toyota with a solid month as well with 27,511 deliveries, although the result was 8.3% off year-ago.

The auto maker benefitted in March from an unusually high mix of fleet sales, comprising 13.5% of its deliveries. Bracken attributes the increase to planned orders from customers and says fleet deliveries by year’s end will settle back to thier more typical 10% of mix.

He also says Toyota will adjust its industry sales outlook upwards, given the first quarter finished about 13% ahead of last year and at a seasonally adjusted annual rate of 14.5 million units.

“With the economic indicators remaining upbeat, we see momentum continuing into the months ahead,” Bracken says, declining to provide exact numbers but indicating the outlook will move from 13.6 million units originally to “a little more than 14 million.”

Toyota is getting more aggressive with its pricing in April, offering available 0% financing on key models, as well as attractive lease rates on nearly every model in its lineup.