I’m building a robot lawnmower with 2 powered 178mm diameter wheels, approximately 8kg load (including these motors), running at ~1000rpm over pretty uneven ground and a maximum slope of 30 degrees. I have 12V with 2~5A available. It seems like I need ~5 N*m (708oz-in/50.1kg-cm) for a safety factor of 2.8. I checked on Reddit and someone suggested the “12V, 165RPM 680.5oz-in Precision Planetary Gearmotor” (ServoCity 638278), which is ~$40 per motor and fairly long (body is 95.1mm). I can make them work, but I wanted to make sure these are the best/most affordable motors for this situation, and see if there were any other options (maybe cheaper or shorter?) anyone would suggest. Any thoughts/feedback would be awesome, looking at motors is starting to drive me insane so I want to figure this out and just order them already 
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@RSIII Welcome to the RobotShop Community. This might help:
For an 8Kg robot, you’ll likely need to select something larger. For comparison:
This uses four planetary DC Gear motors:
If you are only using two such motors, they likely won’t be sufficient.
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