4x4ord wrote:Your 2010 Dmax did NOT have 397 HP. That did not happen until the 2011 models.Huntindog wrote:4x4ord wrote:The problem with Dyno testing todays computerized motors is that different dyno criteria can yield different results.Huntindog wrote:shepstone wrote:GM.Flashman wrote:gmcsmoke wrote:
claiming and achieving are too vastly different things, especially for ford.
True that.
Show me any of the makers that doesn't play the numbers game...
Back in 2010 when Ford and GM were releasing their numbers. GM came out with 397 HP and 765 TQ. That exceeded what Ford had released, and they already had trucks on the road. Ford quickly retrenched with a nice round 400HP 800TQ, even offering a reflash to those the had already bought.
I saw a interview with some of the GM engineers, They were asked why didn't GM just make their Dmax ratings the same as Fords... The answer "We have extensivly tested the Dmax and that is what the numbers came in at. We are confident and comfortable with these numbers."
The Dmax then went on a tear in test after test easily beating the higher rated Ford PSD.
Then the truth about the ratings slowly came out.
GM was the only one that had their power numbers tested to SAE standards....
As has been said, claiming and achieving are two different things.
I remember the Chevy laying the 2011 Ford to waste on the first hill climb tests but it did it with less power. Here is a link to one of the dyno runs on the three trucks from back in 2011.
SAE Dyno specs are the most stringent I know of. It specifies the duration that a power level must be maintained. This matters when climbing a hill.
Motors not tested to SAE standards can use any number they want, as they can set up a motor to put out more power for a short period of time, before pulling the power back to avoid damage.
So the difference is much like a continuous vs peak rating... A higher continuous rating will get you up the entire hill faster vs a peak rated motor being faster for part of the hill.
Although it is possible I find it highly unlikely that Ford would design the new 6.7 Powerstroke to be much stronger than the Duramax (just look at the size of the rods and crank, the compacted graphite block, the massive radiator) and then tune it to deliver 3 more horsepower that only lasts momentarily just to say they have the higher numbers. I had both a 2010 Duramax and a 2011 Powerstroke. On the hills the GM was eager to downshift and rev to 3000 rpm where it made its 397 HP where as the Ford would lug along in a higher gear at 1300 rpm where it made about 200 HP. When racing trucks up hills it is pretty easy to select a trailer weight and grade that will exploit the Ford's laid back attitude.
