Have a Liebherr T284. It’s really, really big. Unladen weight of 237 tonnes and can carry 363 tonnes giving a GVW of an even 600 tonnes.
You have different choices of engine, rising to a 90 litre V20 (yes, a V20!) with up to 4,000 bhp. No gears though as power finds its way to some rather large wheels via electric drive. Braking is done by the same electric motors that do the accelerating.
Options include an electric motor to haul up the access ladder after you’ve climbed aboard.