Porsche has cancelled its plans for a plug-in hybrid-electric 911, citing the weight penalty of the battery pack and excessive manufacturing costs as negatives too hefty to overcome.

Porsche’s head of 718 and 911 development, August Achleitner, revealed to Car and Driver in an interview May 11, the day the brand’s one-millionth 911 rolled off the line, that development of a hybrid 911 was halted last year.

Despite the best efforts of Porsche engineers, it was impossible to compensate for the additional weight of the battery pack, which was said to weigh several hundred pounds in prototype form.

The legendary rear-engined sports car’s dynamics were found to be severely compromised due to the added weight, and the additional power and torque of the electric motor was not enough to compensate for the added heft—at least not around a racetrack.

Furthermore, profit margins on a hybrid 911 would’ve been cut thin due to significantly increased manufacturing costs, and given the historically low take-rate on hybrid cars, it’s likely Porsche would’ve taken a significant financial hit had it gone ahead with the project.

“In the end, the disadvantages outweighed the advantages,” said Achleitner.

Had the hybrid 911 been built, it would’ve slotted into the German automaker’s “992” generation of 911 sports cars, which is set to debut in 2018 as a 2019 model-year car.

Instead of hybridization, Porsche is investing in other technological developments to further improve its next 911’s efficiency—without compromising performance, feel, or excitement.

(Porsche via Car and Driver)