1515 vs 1518

[nuz69]

I use a 1520 on 4S in my 8:scale buggy (inferno mp7.5), and I have the same runtimes with 4000mAh than my friend running a 1515 on 4S with 5000mAh . Temps were 29°C for me and 35°C for him, ambiant was 15°C (FRANCE).
For the same width and design (meaning same windings 1Y and 15 series) the longer the motor is and the more efficient it is whatever the voltage is.
==> the 1520 nomatchs the 1515 in terms of temp and efficiency.

Be carefull on the 1717 : on the one hand the rotor is heavier and larger, the motor is a lot heavier than 15 series motors, so the additional weight can drop the gain of efficiency .
On the other hand, the 1717 and 1520 motors have similar Kv, but the additional inertial rotating energy required to rotate the heavier rotor of the 1717 can drop the efficiency too, but I am not sure on the point, because larger rotor means stronger magnetic field... Maybe someone from Castle who are more qualified can confirm or deny it.
So IMO, 1520 vs 1717, same story, but I would take the 1520 for the (maybe) better ratio power handling/weight.
Hope my English is understandable ^^
Tom.

First of all you English is perfect. I wish the people I work with could write as well as you. It would certainly make my life easier. LOL.

Re. 1717 vs 1518. I pretty much had the same thoughts. I am hoping that the larger diameter rotor will help efficiency but there is going to be only one way to find out for sure so stay tuned for that one. Even if it isn't more efficient at least it will have easier time moving a big truck with huge Big Joe tires and Axial wheels.

Thanks for your help nuz69.