2021 Ram 3500 H.O.

4x4ord wrote:
I realize that altitude, ambient temperature, barometric pressure and humidity make a difference to power output and that goes for both Ford and Ram. You claim at warmer temperatures, say 80 degrees, the Ram might make more HP than the Ford .... maybe, but why? I am saying I am not aware of a reason, are you? Like I said it seems reasonable to me to expect the more efficient engine with a larger cooling capacity to make more HP at hotter temperatures, especially when it has already proved to make more hp at lower temperatures.

Let's take the brand bias out of the equation here and think about what would happen to my truck running its 475 rwhp tune versus the heavy tow 400 rwhp tune.

In very cold 30F temps going up the Ike, my truck can probably sustain the 475 rwhp tune or at least more horsepower that the 400 rwhp tune. Remember, the 400 rwhp tune is just that. It is tuned conservatively for a reason and will not inject more fuel to make more power than that now matter how well it can sustain that power. Adversely, the 475 rwhp tune will inject more fuel to make more power allowing it to go up the hill much faster.

Now imagine each tune going up the Ike at 80F. What would happen? Would I need to back down the 400 rwhp heavy tow tune? No, and I could not back it down even further even if I had to. Would I need to back down the 475 rwhp tune? Yes, I would probably have to back it down to my 400 rwhp heavy tow tune shortly after starting. I may be able to utilize the the 475 rwhp on the onramp at the start of the test to get a good 30-60 mph head start, but I would eventually have to back it down to my 400 rwhp as temps got hot.

Now, will the times of my 400 rwhp tune at both temps change that much? How about my 475 rwhp tune will it's time change that much between the two temps?

I would also not be soo sure about the larger cooling capacity thing. For one, the Superduty has two separate cooling systems, one for the main cooling system that cools the engine, EGR cooler, and so on. The other is for the water to air intercooler which these types of intercoolers tend to get heat soaked under sustained loads very quickly. I know with my truck towing the cattle trailer or tractor between properties versus my father in laws 2019 F350, his fan will kick on way before mine will. Sometimes, mine does even need to kick on while his has already kicked on half way through the trip.