Why different kv ratings for Feigao and Wanderer Motors?
 

My 7XL is running pretty hot in my Supermaxx, so I'm thinking of either an 8XL or 9XL. I run 4s lipo and 1/8 diffs.

The Wanderer 8XL is rated at 1875 kv and the Feigao is 2084. It seems with Wanderer I can use an 8XL and Feigao C XL I would use a 9XL? Or are they just rated differently even though the same?

Or should I just go for the 1950/8? :)

I read one was measured with a load and one was measured without a load.

Go for the 1950 :). The reason there rated differently is because the Feigao's KV is unloaded while the Wanderer's are load values. Go for the Feigao C.

If I go the Feigao C, would an 8XL do me, or 9XL give more room to play -- like 6s perhaps?

9XL would be better. Plus, more torque and runtime.

The 9xl would stay cooler for you if you run the lipo