(Reuters) - When the Nissan Motor Co (7201.T) compact sedan Sentra rolls into U.S. showrooms in the fourth quarter, consumers may notice that it looks a lot like its bigger stable mate, the recently introduced Altima.
Nissan is pinning expectations of increased Sentra sales for the all-new Sentra in part on the more aerodynamic design and resemblance to the better-selling Altima midsize sedan.
"The 2013 Nissan Sentra is the most revolutionary design in the nameplate's 30-year history," said Al Castignetti, vice president and general manager of the Nissan brand in North America.
Nissan has eliminated 150 pounds and increased the small car's aerodynamics to help boost its fuel economy to 39 miles per gallon on the highway and 30 mpg in city driving. Sentra's combined fuel economy rating of 34 mpg is a 13-percent improvement over the current model.
The 2013 Sentra will have a 1.8-liter engine, smaller than the current model's 2-liter engine.
Nissan's compact Sentra has a long way to go if it is going to catch up with the leaders of the compact sedan segment of the U.S. auto industry.
Through July, its sales put it ninth in the segment. No. 1 in the compact sedan segment is the Honda Motor Co (7267.T) Civic, with sales of 187,586, almost three times the Sentra.
Sales of the Sentra are down 11 percent so far this year, at 65,872. This lackluster performance has allowed the Mazda Motor Corp (7261.T) Mazda 3 to overtake it, at 68,554 sold.
Jessica Caldwell, Edmunds.com senior director of industry analysis, said that the Sentra once was among the top compact sedans on the market, but has been passed by better offerings from competitors.
"The compact car market has grown in size and opportunity. More people are looking at it because there are better cars than there were before. The new Sentra is a chance for Nissan to take back its place among the more prominent compact cars," she said.
Competition in the compact sedan segment is keen. The top five entrants all sold well over 100,000 vehicles through July. In order, behind the Honda Civic were the Toyota Motor Corp (7203.T) Corolla, the Ford Motor Co (F.N) Focus, the General Motors Co (GM.N) Chevrolet Cruze, and the Hyundai Motor Co (005380.KS) Elantra.
And the Toyota hybrid entry, the Prius, which is the size of a compact sedan, has sold just over 100,000.
Nissan has not announced pricing for the new Sentra.
Brian Brockman, a company spokesman, said the 2013 Sentra's prices will not change much from the current offering.
The base model of the 2012 Sentra goes for $17,210, and the most-popular offering, the 2.0-liter SV, sells for $19,140. Those prices include destination charges.
The Sentra is the third of five new vehicles that Nissan is introducing in the U.S. market in a 15-month period.
Its top-selling vehicle, the Altima midsize sedan, recently rolled out to U.S. dealers and the Pathfinder crossover SUV will be available nationwide in the fall.
Next year, Nissan will bring out replacements for the Rogue crossover and the Versa subcompact hatchback.
With the new vehicles, Nissan hopes to increase its U.S. market share to 10 percent by 2016 or before, up from its current market share of 8 percent.
Nissan is the No. 7 automaker in the U.S.
Reporting By Bernie Woodall; Editing by Phil Berlowitz