WHY IS THE FI50 RATED MORE HP .THAN THE 10000 POUND GVW SUPER DUTYS ???????

 

They make the same power, they are tested different (I think at less RPM) for emissions! This is how I understood what I read, and I am sure others will explain better!

 

The difference 2006lariat is talking about has to do with the GVWR between the 250's and 350's. Here's a thread discussing the differences between the F150/SD 6.2. https://www.ford-trucks.com/forums/1...ifference.html

The info below is for the F250/F350 hp ratings:

385 hp and 405 lb.-ft. of torque under 10K GVWR.
316 hp and 397 lb.-ft. of torque over 10K GVWR.

 

It all boils down to they are the same engine and have the same power. As stated the over 10k trucks have the performance figures taken at a lower rpm to meet EPA requirements. They still have the same output at higher rpm.

Edit: I just noticed you had said F150. It could be for a bunch or reasons. Different exhaust or intake. Or it may be tuned higher as it has a lower duty cycle and is not expected to work as hard. The only way to find out for sure would be to see if Mike Anderson is still following the "talk to the 6.2 engineer" thread.

 

Think the main differences are going to be cams, exhaust and calibration... Here's my dyno sheet: