America's auto industry, in the midst of a five-year run where sales have rebounded more than 55 percent, is close to seeing a slowdown according to a new study.
The AlixPartners 2014 Automotive Study suggests sales of cars and trucks in the U.S. will hit a peak this year and then gradually pull back.
"This is a cyclical industry and we think this current cycle has just about run its course," said Mark Wakefield of AlixPartners. "We're a little less optimistic than others about the demand for new vehicles staying this strong."
For 2015, AlixPartners estimates U.S. Will peak at 16.7 million before gradually starting to pull back.
Interest rate concerns
A primary reason new vehicle sales are poised to slow down, according to the new study, is the expectation of rising interest rates.
"We're living in an unusually calm world for interest rates," said Wakefield. "We believe the Fed will start to raise rates and when that happens, interest rates for auto loans will also go up."
As a result, Wakefield believes the purchasing power for potential car and truck buyers will diminish.
He calculates a 3 percent rise in interest rates will reduce purchasing power by $2,500 while a jump of 7 percent would cut into consumer's purchasing power by $5,250.
"The threat of higher rates is a very real one and if they go up it will impact auto sales," said Wakefield.
Car sharing rising, China slowing
The latest study by AlixPartners highlights two trends that will alter how many see the auto industry.
In the U.S., car sharing is a fast-growing trend that has many potential buyers now opting to car share instead.
By the end of the decade, an estimated 4 million people will participate in car-sharing programs, up from 1.3 million this year.
Meanwhile, the growth of auto sales in China will be slowing down throughout the rest of this decade.
"China is still the growth engine for the auto industry, but its growth is slowing," said Wakefield.
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By 2020, China auto sales will grow at an estimated annual rate of 3 percent compared to 13.5 percent increase in auto sales for that country last year.
"The sheer size of China means the rate of sales growth will slow down," said Wakefield.
By 2020, an estimated 30 million new vehicles are expected to be sold in China every year according the AlixPartners study.
—By CNBC's Phil LeBeau.
Questions? Comments? BehindTheWheel@cnbc.com.