Ford 6.7L 1050 ft lbs TQ at 1,600 rpm, 475 HP at 2,800 rpm

Huntindog wrote:

4x4ord wrote:

rjstractor wrote:

ShinerBock wrote:
Yeah. If this is sustained power, then it should easily mop the floor with the other two.

Advertisement laws do not require a manufacturer to advertise sustained power numbers. All they have to so is reach a certain power level in a short burst in accordance to SAE procedures which is at low altitudes. Some manufacturers factor in sustained power, and some don't. I wish sustained power numbers was a requirement for the J2807 tow standard meaning you can only advertise the lowest power an engine makes performing the up hill test. I have a feeling that some of the power ratings would drop considerably if it were.

Agreed. I'm not exactly sure how commercial truck engines are rated, but I have a feeling that the early 2000s Freightliner I occasionally drive will put out its rated 515 hp for hours at a time. I'd love to run it up the Ike pulling 60K combined against the new Ford at 40K. I think I know which one would do better...

I think you're right that a 515 hp engine in a heavy duty truck can put out peak power all day long. These pick up truck engines may also be capable of running at peak power all day long. It is possible that the reason they don't make advertised hp on the Ike run is due to the extreme elevation. I wonder if the turbos on the pick up truck engines are capable of pumping enough air at 10,000 feet elevation to allow full fuel to be delivered? Maybe fuel is restricted under those conditions to prevent excessive exhaust gas temperatures?

What it boils down to is the differences in the testing to arrive at the "advertised" HP/TQ numbers. There ARE different parameters. Some require a longer duration of the rated power than others.... This is why some manufacturers always have the highest ratings, but not always the best performance. They likely gain some sales from the high advertised numbers from those that do not look into just how/if that equates to the best performance

I do believe that the HD trucks will be vastly superior in that regard... But I also believe that if they are pushed hard enough they too will reduce power. It just doesn't make sense to let a motor hurt itself when you can prevent it with todays computerized ECMs.

The testing is the same per SAE standards. There are slight difference between the SAE J1349 that Ford uses and the J1995 that Cummins uses. The J2723 that GM uses still uses either J1995 or J1349 as their dyno standard, but has an extra validation step.

There are a lot of tolerance and correction factors that can be fudged on these tests. For example, there are plus or minus factors in the calibration of the equipment used and even the temp. A company can set their test to have the best possible scenario to be able to post the highest numbers. Sure it is sneaky, but it is still legit per SAE standards.

The other thing is that these test are short burst runs and not sustained power ratings as I stated before. The SAE and advertisement law requirements do not force manufacturers to advertise power ratings at their max GCWR up X grade in Y temp at Z altitude for a set amount of time. This is up to the manufacturers discretion just as Cummins does for many of their engines stating that the power level is good up to X altitude(usually 10k ft) in their engine spec sheets. All it states is that they cannot advertise more than what the SAE test and they have to point out the type of fuel used if it is anything other than standard fuel.