Yes the 010's will have e-fans. A general rule of thumb is for every 10amp additional draw, you will lose 0.1 mpg. Alternators are only about 65 - 73% efficient at converting mechanical to electrical energy. With these e-fans, you will also need a bigger battery to support energy needs which isn't a bad thing but does add weight to a vehicle. But the mechanical fans are more efficient than they were before the gas price crunch which started only 3 - 4 years ago. Overall they are likely more efficient than the mechanicals. Another benefit is the added space to work on the engine between radiator and engine.