Difference Brand Motors, Same Size & KV's, 20% Difference in Amps?

Being new to electrics, while looking at 40mm motors, I saw something that's confusing. The difference in the amps between the SSS and the Leopard motors of the same size and KV rating is about a 20+% difference. The hypothetical question, using 6S and 1500KV, the rpm is about 33,000. If the SSS is 100 amps, it appears the Leopard is going to be about 120+ amps. I can't believe the SSS motor is just more efficient than the Leopard. Am I correct to think the SSS motor is not going to give the same speed as the Leopard or is my thinking flawed? Now my mind wondered to choosing a ESC with this much difference in amp ratings?...

KV for KV, same size can, same prop, same cell count. I don't think the ampdraw will be that much different in a practical application.

In fact I have tried more than one brand and that wasn't the case.

Some brand would perform a little better though.

Just out of curiosity, what amp draw would your trust, Leopard or SSS?...

I have not seen the resistance listed for sss so its hard for me to comment on they max amp rating. I can confidently tell you leopard max amp rating is a safe rating to work with.

Keep in mind that max amp rating and constant amp rating is not the same. If the divide max amp by 2 you would have a safe ampdraw for constant amps.

The specs that you see listed in the spec sheet is the maximum that the manufacture recommend.

The amps a motor will pull is determined by kV, voltage, resistance in the drive line, propeller size and blade design, how deep the prop is in the water just to list a few.

Circuit racing is constant amps and saw record trial is maximum amps.

Thanks, I'm still learning and slowly getting there...
Barry

Hi Barry
Straight up 'guessing' is going to get you in trouble. When it comes to motors it is not just can diameter or even length that will determine amp draw. To start with, manufacturers specs are just that. More pertinent is wattage rating. There are differences within motors that will have an effect on efficiency and current draw, such as how much copper wire is wound in them and the strength of the magnets.
However, on the water it comes down to a combination of hull, motor, prop and how well the whole setup is tuned. Put the wrong prop on and you will find current draw increase dramatically.
BTW the SSS may well be more efficient than the Leopard, but in lieu of proper testing that is all conjecture.
Ask more questions specifically around what you want to build and achieve. There is a huge amount of experience and good advice here on OSE.

Peter is right. Tell these guys what yer building and what you want to do with it. They'll give you better advice. Don't be afraid to say ya don't know either. Everybody starts that way.

The amp ratings and even the watt ratings are just what the manufacturer feels they're motors can produce without burning to a crisp. They're not always apples to apples as there is no standard for coming up with the ratings. Same with ESC.

There are always a multitude of ways to get where you want to go with these silly thing.

Thanks for the great advice. Once I have some more ideas of what I'm interested in doing, I'll put it in writing to see what the thinking is on it...
Barry