Lower hp ratings in HD trucks
I know it has been discussed here before, but I found a real answer so thought I'd bring it up. Example, the Ford 6.2L V8 and the RAM 6.4L Hemi are both rated for less power when the truck's GVWR e...
Forum Discussion
fla-gypsy wrote:
The Ford engineer stated quite clearly there was no difference in the Ford motors they rated differently. They were not de-tuned, etc. They simply measured the HP/Tq at a lower RPM to meet the silly EPA noise regulations. If you own one of these de-rated motors rest assured it makes the same power at the same RPM as the higher rated motor.
I've been searching around the internet and found several references that say the same thing. Apparently they run the engine up on the dyno until the noise level gets to the limit and that's the point where the peak HP reading is measured.
