If 2 brushed dc motors (both 12v) produce about the same torque at max efficiency, but one draws about 2.5A while the other draws about 10A I would assume that the first motor would have 4 times the efficiency. And, I would assume that the first motor would run much longer on the same batteries. However, the datasheets say the first motor runs at 79% efficiency while the second motor runs at 74%. How is it possible that the efficiency is so close and what am I missing? BTW, the first motor is rated at abt 5,000 rpm while the second is abt 17,000. Thank you!
I understand my question a little better now, but any response would still be appreciated. I was not considering that while torque is the same the power output (or work being done) is different because the rpms are not the same. I looked at the output power in watts at max efficiency and found the (about) 4:1 ratio I was looking for - the first motor is 26w while the second is 96w.
You are correct that since the rpm is not the same, there is a difference between the two motors which can affects the total power available.