S60 Detroit power question.
So here's a little info on the truck at hand:
2003 Freightliner Columbia 239 WB
S60 12.7 370/430---Currently set at 430/430
Eaton Single OD 13 speed (.85)
2.93 rears
22.5 LP's
I pull intermodal, it's cheap, heavy and a pain in the ###. I drive 65 everywhere. That puts me at 1400rpms's +/- and seems to run/pull well at that speed. Problem is, I only seem to be getting around 6-6.25 mpg. When I drove a company truck before, pulling the same freight, weight and route with a much weaker lower geared truck, I'd average about 6.5-7 mpg. It was a Volvo daycab, Volvo D12 385hp, 3.90 rears, 10sp OD (.74), Tall 22.5's. I usually went 70mph which was about 1700rpm's. It was their fuel right?
So my question is, what if I were to turn the power settings back down to 370/430, or to 370/370 for that matter? Does 60 hp really make that much difference? From what I've learned, HP doesn't exceed Torque until 5252rpm's. And I'm pretty sure the truck will never see that. So what's the point of having the HP upped if the torque doesn't change at all? I'm just trying to find a way to save a little cash. .5-1.0 mpg could save me about 250.00 per week.
Thanks
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