BERLIN (AP) — BMW's CEO says that at some future point it will no longer make economic sense to keep adapting diesel engines to ever-tougher rules, but he isn't saying when.

Harald Krueger was quoted Tuesday as telling German daily Handelsblatt that the European Union's fuel consumption and emission targets for 2020 and beyond can only be achieved with diesel.

He added, however, that "the point will come in the future when it will simply be uneconomic to adapt the diesel drive ever further to the demands of increasingly ambitious legislation." Electric power will then play "the decisive role."

Asked what effect the diesel emissions cheating scandal at Volkswagen has had at BMW, Krueger said there has been no impact yet on demand but it's too early to calculate the long-term consequences.