Electric Chicken
Well-Known Member
They didn't turn us up. We tach about 1350-ish @60.
Detroit DD13 vs DD15 for 80,000 lbs: Fuel Economy, Power, and Maintenance Costs
They turned the OTR drivers up quite a while back to 63.
Electric Chicken
Well-Known Member
Yeah we've been whining about it ever since.
I don't care much personally. It wouldn't help much. Maybe let me nap 45-60 mins instead of 30 some days.
Besides, if we can go faster they're gonna expect more. I already do plenty.
mndriver
curmudgeon extraordinare
I had zero issues holding or accelerating.
But then again, I was turnt up to 630/2350 too.
Never cared about running 70-75.
But I sure wanted to know I wasn't gonna slow down for every bump in the road.
Looks like DD15 for me as well.
Curious, why the change?
Electric Chicken
Well-Known Member
Ultimately, it was endless debates with engineering.
There was quite a bit of concerns with startability by these guys, even though the spec sheets show identical numbers regarding this. It was explained that the stats they provided me are simply based on HP and Torque ratings, but that startability would be better with the DD15. They were really pushing me to go with lower rear axle gears and an OD trans. OD trans is out of the question, as my goal is to operate in direct drive, and dropping down to a 2.28 rear axle ratio won't work for what I want the truck to do. Personally, I think the DD13 would perform just fine, but it's enough of a concern to think about.
Fuel economy: It was acknowledged that the DD13, with the gear setup I want, would do a tiny bit better on flat land, but any gains would be lost if I operate very much in hills. Well, I'm in Northwest Arkansas and everything I take off with each week puts me immediately in hills along I44. Combine that with my desire to run more out west once I get another truck, and I will see even more hills. Both motors will perform fine, but I'm likely not going to see any net gain in fuel economy unless I stay in the midwest.
Resale value: In the end, this was the tiebreaker. By the time this truck reaches 5 years old, it will likely be in the hands of another driver. Resale value on the truck is more than $5k better with the DD15, so the ROI is in favor of the bigger motor here. Same reason I went with duals over wide singles. I felt fine with the wide singles, and was leaning toward them, but they are a deterrent when it comes to resale. Talking to dealers around here, they will actually pull the singles off and put dual on whatever they are trying to sell on the used lot.
That's the difference. I accelerate will with this engine, but it puts out well over 500hp.
Still, though, peak torque is at 1400, it holds great there, but acceleration is much better at higher RPM's.
r3gulator3
IMA KEEP IT REDNECK
1400 is a good cruise speed for a DD engine, however over 1600. Your just throwing money out the tail pipe.
I can see the extra rotational mass of the DD15 helping startibility, even if the engagement torque specs were identical.
Have you considered going with an 18 speed for the extra low low gear, and just run it in direct? Cowpie over on the dark side has a glider set up like that and it's doing well.
Have you considered going with an 18 speed for the extra low low gear, and just run it in direct? Cowpie over on the dark side has a glider set up like that and it's doing well.
I'm stuck on the DT12 automatic for this truck, hoping to get a bit of an MPG boost with the coast mode that it has in the top gear.
Frame has been shortened from the stock 229 to 227. Not really noticeable from the eye, but it puts the trailer another couple inches closer to the truck.
This is the color, and actually the same wheelbase. 227 is the shortest allowed and still have room for an APU should I choose to add one. Everything on the exterior is the same except for wheel covers, vented mud flaps, and I might powder coat the front wheels.
This is the color, and actually the same wheelbase. 227 is the shortest allowed and still have room for an APU should I choose to add one. Everything on the exterior is the same except for wheel covers, vented mud flaps, and I might powder coat the front wheels.
I will, but cheaper to do it myself.
Electric Chicken
Well-Known Member
Fleet white. Sexy.
Radiant Snow?
Radiant Snow?
No, not fleet white. Fleet white is the dirtiest white you can imagine.
Electric Chicken
Well-Known Member
Schneider White.
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