Torque Curve Question

[Greenleaf]

From the adds I read, the other guys have more HP and (I think) more torque. I also understan that there are a ton of uneducated folks out there that ONLY look at HP and "maybe" the torque figgures... ... ... ... .



What is the torque curve of the three popular diesels in the big three pick-up trucks? I know enough that it should be flat... ... ... ... ... . very flat. I have the graph of the Cummins ISB 5. 9 and it shows about six different engine rates which all seem very very flat.

 

[KCJackson]

There's a reason that Dodge and Cummins list the hp peak of the pickup engine at exactly 3013 rpm.



<font="Courier New">350 hp x 5252

-------------- = 610 lb-ft

3013 rpm

</font>



Remember the manual-trans engine is rated at 350/610 - it's dead-flat from 1400 to 3013 rpm. The automatic version comes in higher to get to 650 at 1500, then gradually glides down to 610 at 3013.



Ford's 6. 4 is rated at 350@3000 and 650@2000. Torque fall-off is much steeper over a shorter range.



GM will up the Duramax to 365@3200 and 660@1600 for January. Torque at the hp peak is 599 - a gradual decline like the Cummins/automatic.