F350 Super Duty vs 3500 Denali vs The Ike Pulling 30k lbs

^^^ Its really hard to say. Maybe GM is wanting cooler temps so the cooling fan never shut off. My Ford runs up to 205 *F in minus 5*F weather cruising down the level highway without a trailer. The GM ran in its peak hp range the whole way up the hill and yet put less power to the pavement than the Ford did running at 2200 rpm. If that big cooling fan was running continuous it may have robbed an awful lot of HP.