SAN FRANCISCO – Volkswagen of America soon will launch the new ’15 Golf hatchback, the second vehicle to be sold in the U.S. that is based on the automaker’s MQB modular architecture.

The first U.S. MQB vehicle, the Audi A3, demonstrates the possibilities for the architecture, which can shoulder vehicles as small as the Audi TT to models as large as the upcoming VW CrossBlue CUV.

The modular platform strategy allows VW to share parts among vehicle ranges, reducing costs and engineering effort, but does carry some risks, says Marc Trahan, VWA executive vice president-group quality.

“The risk is that if we have a quality spill, if there is an issue, you have the potential to infect a lot more vehicles,” Trahan tells WardsAuto at a Golf drive event here. “So you have to be vigilant and diligent.”

MQB platform derivatives already underpin vehicles from VW’s foreign makes such as Skoda and SEAT. In addition to the Audi A3 and new Golf, the architecture will shoulder a number of Golf derivatives, including the GTI, Golf Sportwagen, e-Golf electric vehicle and Golf R performance car.

“It blows me away to see the diversity of all the different cars that we built so far on this MQB platform,” Trahan says. “There is a lot of flexibility.”

Another risk to the modular platform strategy is having vehicles across various product lines that are too similar in look, feel and driving characteristics. Trahan says VW has spent significant effort to maintain each vehicle’s unique personality.

“We don’t want to turn into a General Motors of the past,” he says. “We have to allow every brand and model to have the differentiation to justify itself in terms of the consumer.”

The upcoming U.S. Golf lineup will put the strategy to the test. The base ’15 Golf will be offered with two or four doors and two powertrains – a 1.8L turbocharged 4-cyl. and a 2.0 turbocharged diesel engine. The performance-oriented GTI will be powered by a 2.0L direct-injected turbocharged gasoline 4-cyl., while the uplevel Golf R will get a 290-hp turbocharged 4-cyl. mill.

The Golf Sportwagen makes its U.S. debut, although the previous generation was sold in the U.S. under as a Jetta.

“Now, for a lot of reasons, we made a significant investment and commitment to increase the market footprint for the Golf here in the U.S.,” Trahan says. “That’s why we’re going to bring in all these derivatives. We’re going to establish the Golf as a full-fledged model range.”

The ’15 e-Golf, VW’s first fully electric vehicle for the U.S., is due to go on sale in select states in the fourth quarter. Trahan says the electric drivetrain was developed in-house by VW, noting even the battery packs are assembled by the automaker, a strategy that runs counter to some other OEMs who farm out electric drivetrain development to suppliers.

Although VW is relatively new to EV development, Trahan expects no quality issues with the e-Golf.

“My role in North America is to be more or less a (quality) gatekeeper,” he says. “We have some input upfront in design concept features, but primarily I look at the process afterwards and make sure it meets our standards and, if not, keep it out of market until it’s ready.”

bpope@wardsauto.com