The current Guinness World Record for longest EV drive on a single charge is held by Lucid Motors, for a 749-mile journey made by the company’s Air Grand Touring sedan. Lucid grabbed the title from a Mercedes-Benz EQS 450+, which traveled 649 miles.

GM said it was important to set a record only after optimizing the vehicle in ways real customers could replicate at home.

Driving at low speeds with no air conditioning may not be ideal for most drivers, but the test showed just how far current EV batteries can be pushed in optimal conditions.