Duramax is king of the mountain again
Clicky
Forum Discussion
Cummins12V98 wrote:There has been lots of speculation since 2011 or so as to why that is.
GM is very clear about SAE Flywheel horsepower. Seems they always did well with "less power".
Many at first (and some still) think that GM was sandbagging their ratings. This never made any sense to me, as that would sacrifice sales to those that want to buy the truck with the most power.
Quite a few think that the Allison has much less power loss. I never really bought into that. It may have been true in the past, but the Ram and Fords offerings are much improved over what they had. I doubt there is much difference anymore.
One of the hill climb tests I read did it different. They ran the trucks at the same time together rather than seperate timed runs. They wrote that at certain times, the Ford seemed like it had more power as it was able to pull away from the GM... But these incidences were brief. Overall, the GM was faster.
Later I read here on this forum about GM being the only one that followed the SAE protocols for Dyno testing. That was an eye opener for me.
With todays computer controlled motors, it is pretty easy for a motors power to be increased briefly until the computer detects imminent damage, and reduces the power.
SAE testing is very specific, as to the duration a motor must produce the rated power. Not using SAE dyno standards would allow for a higher HP/TQ figure to be obtained... Hence the term "advertised power"
This fits in with what the magazine testers observed, and explains why GM was so confident in the Dmaxs power ratings.
So that is what I have come to believe after trying to understand why the GM was winning all the hill climbs with less power.
IOW, the Ford had advertised power, and the GM had real power. Only one counts when climbing a hill
