BMW Motorsport Director Jens Marquardt believes the GT3 platform will no longer be sustainable if manufacturers continue to pour money into its so-called customer teams.

A number of GT3-based championships, including the Blancpain GT Series and the GT Daytona class of the IMSA WeatherTech SportsCar Championship, have seen a greater concentration of factory or works-supported operations in recent years.

The movement has pushed out a number of gentlemen drivers out of the platform, due to rising costs and the inability to compete alongside all-pro lineups with factory drivers, despite some series, such as the WeatherTech Championship, being Pro-Am enforced.

Marquardt has warned of the platform’s eventual collapse, should manufacturer support eventually end.

“For me, I would say this is not sustainable on that level,” he told Sportscar365. “It is a marketing activity for a manufacturer and then two years down the road they stop the marketing activity and then what do the customers do?

“That’s for sure not the BMW approach. We’ve really had very loyal customers to us and we’ve sold cars that are running really quite well in all championships.

“We help with drivers or technical support where we can and really help the teams to extract the real potential from the car, but that’s as far as it goes.

“If you look at it, we have been reasonably successful in that respect.”

While SRO has begun to take measures, in the limitation of all-pro lineups for the Blancpain GT Series Endurance Cup for 2018, Marquardt said he’s most concerned about GT3’s future in IMSA.

The arrivals of both Acura and Lexus, initially under an agreement for only a single year of factory involvement, has led to other manufacturers stepping up its involvement in the class, whether through driver, engineering and/or financial support.

What’s more, IMSA has already taken a hit in full-season entries compared to last year.

Of the 21 GTD cars for next weekend’s Rolex 24 at Daytona, only 11 are so far confirmed for the entire championship, compared to 15 from last year.

“If you look at the field here [in IMSA], honestly speaking, I think there is half and half customer and works effort,” Marquardt said.

“Lexus has two cars which, for me, are works cars. Acura’s main cars are also works cars.

“I have full respect for a guy like Will Turner who tries every year to get drivers together, to get a package together, to race in this super-highly competitive field. He is a true customer to us, so it is a difficult environment.”

Marquardt said he’s seen a similar situation develop in Europe, where manufacturers offer cars to customers at heavily discounted rates and other perks in order to switch to that brand.

“We’ve had teams that have been with us for a while come to us and say, ‘Look, you have to understand. We have to look at it commercially and what we’re getting as an offer from this other brand is good.

“‘We’d pay one-third of what we’d pay with you guys and get two cars and support and this and that.’

“At the end of the day, you have to understand that those guys really have to still make a living with the people they have.

“Obviously there are manufacturers that spend a lot of money on pulling people from one brand to another but for me, this is customer racing,” Marquardt said.

“I don’t think it’s the the right approach to basically sell the car half-price with a big package of parts or whatever.

“Other people can afford and want to [do that] but it’s not the strategy that BMW has.”