You are not taking into account that the belt driven fan has a clutch and only truly engages when enough heat eminates from the radiator (heavy stop-n-go traffic). My '06 Ram (Hemi) has the belt driven fan and is basically free wheeling at highway speeds - it's not truly engaged. Basically the only time I hear it engaged is after a cold start. Once I get over 25 mph once, I hear it disengage and rarely hear it engage - even in stop-n-go traffic.My car turns 2600 RPM at 65 mph, a mechanical fan would be spinning fast for no good reason, whereas my electric fan never comes on during the vast majority of my commute (unless I put the A/C on).
I would think it has more to with what is required. DRL's are not required in the US, but are mandatory in Canada. As you posted, the dealer can simply enable the feature.I just had the dealer enable the DRLs on my new Ram and they finished the task in no time and didn't charge me anything. It seems like a proven safety improvement and I'm surprised they sort of hide it.
I found a study on the Internet:Please explain to me how a mechanical fan inherently will move more air than an electric one.
Compared to some alternator information:CONCLUSIONS
Median efficiency of the surveyed industrial and agricultural
belt types and constructions is 96 per cent. Within
rated and application power levels, efficiency ranges from
90 to 99 per cent depending on belt type, construction, and
application parameters. Both median and range agree with
historical data.
I did not find any information about efficiency of electric fan motors.Efficiency of automotive alternators is limited by fan cooling loss, bearing loss, iron loss, copper loss, and the voltage drop in the diode bridges. At partial load efficiency is between 50-62% depending on the size of alternator and varies with alternator speed.