[lincpimp]

With proper cooling the 580L should be able to produce more watts than a 1515. Now you will not be able to get proper cooling for the 580L in a vehicle so that point is moot. I have a feeling the 1521 will produce more power due to its greater efficiency and will run cooler at those power levels. I have run plenty of 1521 and 1515 motors, and find they are the best you can get for heavier road/track vehicles.

For the sport boater the 580l is a decent alternative to a more expensive neu. Keep in mind the water cooling will keep the motor temps in an acceptable range, and the only down side will be shorter runtimes due to the lower efficiency compared to a neu.

So bottom line is that the 580l is a poor choice for a vehicle, the castle 2200 motor can be had for similar cost, and will perform better in just about any setup.