Electric motors do need to be lubricated in order to protect the bearings against wear and tear from friction.
However some electric motors have sealed bearings which are permanently lubricated and require no constant lubrication maintenance.
Some electric motors use oil and some use grease and if your electric motor has oil ports then it requires oil and if the electric motor has grease zerks then it takes grease from a grease gun.
The best lubricant for an electric motor depends on the electric motor as some electric motors use grease and other electric motors use oil.
For electric motors that use grease a synthetic GIV, PAO base oil grease with an NLGI 2 or 3 consistency is often the best lubricant for electric motors that require grease.
For electric motors that take oil for lubrication often 3 in 1 motor oil or SAE 20 motor oil is the best lubricants for most electric motors.
When oiling an electric motor you put between 2 to 4 drops of oil into the electric motor for each bearing, depending on the size of the electric motor.
Generally you can just put the oil into the electric motor a drop or two at a time until the oil reaches the top of the oil port.
Avoid over oiling the electric motor though as it can cause damage.
Electric motors require oil if the electric motor has oil ports which are located on each end of the motor housing where the motor shaft exits the motor.
Some electric motors have sealed bearings and don't require any oil and if there's no oil ports or grease ports the electric motor does not need any oil or grease.
But if the electric motor does have oil ports or grease ports they need oil or grease to keep the bearings lubricated.
The kind of oil that you use in a small electric motor is often 3 in 1 motor oil or SAE 20 motor oil.
The best oil for electric motors including small electric motors is 3 in 1 motor oil or SAE 20 motor oil.
3 in 1 motor oil or 3 in 1 oil in general is best for electric motors for lubrication.
3 in 1 motor oil is the best for electric motor bearing lubrication.
SAE 20 motor oil can also work in electric motors for lubrication.
WD-40 is OK for electric motors when cleaning and freeing up any stuck components although WD-40 shouldn't be used as a lubricant for the bearings as WD-40 is not an actual lubricant but is instead mainly a cleaner and penetrating solvent.
3 in 1 motor oil is different than the regular 3 in 1 oil.
Some larger electric motors may require grease or a thicker oil depending on the size of the electric motor although most household sized electric motors can use 3 in 1 motor oil or SAE 20 motor oil.
10W 20 motor oil or other light oils can also work for small electric motors.
And for electric motors that need grease, the grease consistency preferred for electric motors is normally NLGI 2 or 3, with a base oil viscosity of 100-150 cSt @ 40°C or 104 F.