Dear Abby,
I is confused.,
Or maybe I am just dense, but one thing I don't get,
How does horse power effect fuel economy?
Identical trucks ie;
Kenworth T300s 33,000 GVW
Eaton Ultrashift transmission,
Cummins ISC engine
same box, weight etc.,
How does the HP of the Cummins (240, 260, 285, 300 or 315)
effect the fuel usage? Is it HP or displacement or what?
I get that the bigger engine will pull weight/do hills better,
But assume level grade 55 mpg 33,000 lb. truck, it will take "X"
number of foot pounds ( or thrust or HP ) to keep it moving at a steady
55 mph.
So a 315 HP will be running less to generate "X" And a 240 HP is running harder to generate "X" using the same amount of fuel?
Better MPG with a bigger engine and higher rear-end gears and/or overdrive tranny?
Will the 315 last longer?
Signed
Confused