The new BMW 3 Series Gran Turismo -- M Sport Package. Photo: BMW. 

Thanks to its wildly popular 3 Series, in August, BMW (BAMXF -0.19%) saw its brand sales surge 45.7% compared with the same time last year. Even better? The 3 Series dominated sales compared with Daimler's (MBGA.F -0.56%) Mercedes-Benz C-class. Plus, since Sept. 1, 2010, BMW's stock has risen 69.17%. Here's what else you need to know.  

Luxury brand power
On Sept. 4, BMW reported its August sales results, and they're impressive:

  • 6,835 3 Series, a 66.9% increase.
  • 4,359 5 Series, a 158.2% increase.
  • 924 7 Series, a 172.6% increase.

Moreover, year-to-date, BMW brand sales came in at 188,997, compared with 164,636 through this time last year. That's a 14.8% increase. Further, BMW states, "Sales of BMW brand vehicles increased 45.7 percent in August for a total of 24,523 compared to 16,835 vehicles sold in August 2012."  

2013 Mercedes-Benz C250 Coupe. Photo: media.mbusa.com.

Mercedes, on the other hand, saw its eighth record-breaking month of 2013, with units sold coming in at 27,144. However, while that's more than BMW's units sold, it's an increase of only 15.8% -- still great, but nowhere near BMW's jump. Moreover, the C-Class came in at 6,701 units sold, up 2.8%, but still significantly less than BMW's 3 Series.  

What's driving sales?
Both the C-Class and 3 Series compete in the compact luxury sport sedan segment, and both are powered by four-cylinder turbocharged engines in their entry-level versions. However, for their entry-level versions, the C250 uses a 1.8-liter turbocharged, direct-injected four-cylinder engine with 201 horsepower and 229 pound-feet of torque, while the 320i has a 2.0-liter turbocharged, direct-injected engine, with 180 horsepower and 200 pound-feet of torque.

The New BMW 320i Sedan. Photo: BMW

For miles per gallon, Mercedes' C-Class comes in at 22/31 mpg, while the 3 Series gets 24/36 mpg. Further, the C-Class has a starting MSRP of $38,200, while the 3 Series has a starting MSRP of $32,550. 

Besides that, the two vehicles are similar in terms of consumer ratings, safety rating, and reliability, according to Edmunds. So, what could be driving sales is a lower cost of entry: The BMW is cheaper -- although if you compare the C300 with the 328I, that price difference is negligible. 

Sales in the future
Last year, Mercedes took home the title of best-selling luxury brand in America -- the world's top luxury-car market. But this year, BMW is expected to claim that title. Another factor investors should consider is China, whose premium-car market has increased by a compounded annual rate of 36% in the past decade. In fact, China's luxury auto segment is expected to climb 7% to 12% this year, which is great news for luxury-car makers. More pointedly, in 2012, BMW had a 23.6% luxury market share, which was second only to Volkswagen's (VWAGY -0.16%) Audi market share of 29.6%. These numbers show that BMW is in a prime position to capitalize on China's auto market, which is great news for investors. As such, BMW could make a great investment.