The maximum torque of the hub motor is 78 N-m or 57 lb-ft. If the tire is 24" diameter the amount of force it can exert is 57 lb. Assume you have four of these motors you will have a force of 228 lb. If your vehicle is 2280 lb, it would be just barely enough for a 10% grade.
The speed is determined by the circumference of the tire, about 6.3 feet, so at 1300 RPM that's 8190 ft/min or 93 MPH. So 160 kM/hr is believable. But you really need more torque.
[edit] I thought these motors were designed to connect to the wheel through a CV joint. But that was the
WEEL motor. If that's the case you don't need a hub motor.
The "hubcap motor" project from Turquoise is interesting. I also had an idea for a bolt-on hybrid conversion kit, but adding the weight (and size) of a motor on the outside of the wheel may adversely affect the driving characteristics.
Good luck!