To me, it depends. And you low living, sea dwelling creatures be damned! (I used to be one…). But now I live at altitude amongst big F N hills like I70 going over multiple passes for miles, and I’m towing 2000lbs riding on 33’s. It’s how I want to be, that’s a choice. Maybe not 65, but at least 50 mph. For miles. Up steep hills. with temp in the 90’s cause that has been all damn summer. 24% less cooling, just in the Hills like Breck! But I’ve been running electric fans. And AC. It’s near impossible In these 98F days, like today while towing. Been that way with LS, R2.8, 200 tdi, 4.6, 3.9, 4.0 …And screw electric fans for these conditions. I’m going back to mechanical. Other shit can’t keep up and mechanical is the path for me. 10,000‘ passes with todays speeds (even close), requires it. I’m working on mechanical shroud now For the cummins. for this, max cooling and that is aluminum.
Now, transport me to a 90 at sea level not planning to tow a trailer—like in CA or Mississippi (low elevation) different story even at 100F ambient.. I’d take copper for longevity, and have done just that. Would do it again. Solid choice. It’s only when you’re squeaking for cooling, but ya know what? End results the same. Good for then engine. Good cooling, good thermostat. Engine runs in design range. Simple as that for max reliability.
