Japanese carmakers are eyeing big US sales gains after introducing a slew of new vehicles for the American market but face stiff competition from a resurgent Detroit and ambitious Koreans and Germans.

Toyota and Honda saw sales tumble in 2011 after supplies were smashed by the devastating March earthquake-tsunami-nuclear disaster in Japan.

It came at a particularly bad time for Toyota, which was finally recovering from a reputation-shattering series of mass safety recalls.

The supply shortages also provided an opportunity for Ford, General Motors and Chrysler to capture new customers after years of painful restructuring resulted in radical revamps of their product offerings.

"The problem for Toyota and Honda is that some of their market share losses are potentially permanent losses because the competition is so much better," said Jesse Toprak, an analyst with TrueCar.com.

"Consumers who would have bought a Toyota or Honda ended up getting something else and realized these cars are as good or better."

Asian automakers dethroned the Detroit Three in 2009 as the biggest sellers in the US market as overall industry sales tumbled amidst a deep economic downturn that pushed GM and Chrysler into a government-backed bankruptcy.

That trend reversed in 2011, when losses at Toyota and Honda pushed the Asian share down to 43.7 percent while US carmakers captured 46.9 percent, according to the research firm Autodata.

With total industry sales forecast to grow to 13.5 million vehicles in 2012 after posting a 10 percent gain to 12.8 million last year, there should be plenty of new customers to go around.

"We're extremely bullish on the market and how we're going to perform in it," Bob Carter, who heads the Toyota division of the group's US sales team, told AFP on the sidelines of the show.

Toyota is launching 19 new products this year across its four brands: Toyota, Lexus, Scion and Prius.

Its fresh approach to styling was on display Tuesday at the Detroit Auto Show when it unveiled the latest addition to its Prius family -- the c hatchback -- and the NS4 prototype of its first plug-in to be launched under the Toyota brand in 2015.

Lexus chief Mark Templin vowed to handily recapture the coveted luxury crown lost last year when Lexus was overtaken by BMW and Mercedes after 11 years of dominance.

"Our base plan -- which we expect to exceed by a wide margin -- is 240,000 units which is 21 percent growth" in 2012, Templin told reporters after introducing the prototype of a sexy new sports car the LF-LC Monday.

Toyota forecasts its market share will grow by about one point as 2012 group sales in the US rise 19 percent to 1.9 million vehicles after falling seven percent to 1.6 million vehicles in 2011.

Honda, which was hit by mass flooding at factories in Thailand just as its production was getting back on line, also has ambitious goals.

It expects to boost US sales by 25 percent in 2012, after posting a 7.1 percent loss in 2011.

Honda introduced the 2013 update to its top-selling Accord sedan at the Detroit show Tuesday after previewing three prototypes from its luxury Acura brand Monday.

"Many of our competitors were enjoying the race with Honda running at half throttle and temporarily picked up a few laps while we were in pits," the John Mendel, executive vice president of sales for American Honda, said Tuesday.

"We're here to serve notice to the competition that Honda is again firing on all cylinders. We're back to full power and racing with a vengeance."

Nissan, whose suppliers were not badly hit by the Japanese disaster, posted a 14 percent jump in US sales to 1.04 million vehicles in 2011 after an 18 percent jump in 2010.

Its US market share rose 0.4 points to 8.2 percent, edging up against Honda, which holds fifth place in the crowded US market with a nine percent share.

It plans to grow US sales in 2012 by about 10 percent, which is around the industry's forecasted growth pace, said Bill Krueger, Nissan's chief of the Americas region.

"We have seen steady growth in the US and on our own current trajectory we expect to continue to grow," he told AFP.

That will likely prevent the second largest Japanese automaker from reaching its target of a 10 percent bite of the US market this year, but Krueger said it is an "inevitable milestone."

With Nissan's US plants nearly at capacity -- and upcoming plants in Mexico and Brazil still a couple year away from production -- supply is more of an issue than demand, he added.