Cummins 6.7 vs other motors

[FireGuard]

I see many of the newer DP's are using the Cummins 6.7L that was updated from the 5.9L.
I know in the Ram trucks they are 385 hp and 800 or 850 ft/lb depending on transmissions.
Anyone have this engine in a new DP and if so what are the HP/TQ ratings and how does it do with real world power/performance?
What transmission are they using? I'm assuming an Allison 3000??
I could see the advantage of a Cat 330 over a 5.9L, but I'm thinking the 6.7L should be pretty close to the Cat performance.
What are your opinions?

[michelb]

et2 wrote:
Had three 5.9 and on my third 6.7. All have been in a Ram p/u except this one which is in our new 2103 Fleetwood Expedition 40x . Towing the toad we are at around 32500 combined. It is rated at 360 on this model with 800 or so of torque.

I've never had any power issues with any of them, and the MH is 42'. It pulls and drives just fine. We tow a Jeep Liberty at around 4500 lbs. I set it on economy on the trans and set the cruise and there isn't an issue. It hardly ever downshifts on the hills.

The Fleetwood Discovery is rated at 380 hspwr and 1000 on the torgue. I don't know how much bigger you need to go before a different engine is needed. I probably don't have the money for one of those MH's.

Just to be clear, the Discovery at 380/1000 has an 8.3ISC not the 6.7ISB.

[bobmacc]

I have a 2009 Winn Journey with the ISB6.7. It is rated at 350HP and 750 ft-lbs torque and is coupled with the Allison 3000 transmission. The coach is about 27,500lbs loaded and we tow a 3500lb toad. It is well powered even in the mountains using the transmission to advantage. Gets 8-10 mpg generally depending on terrain and wind.

[wolfe10]

Old-Biscuit wrote:
Isn't the 330 CAT (8.3L) rated at 330 HP and 860 lbs. torque?

HP and torque are accurate up to 2004. More HP and torque on newer ones. Displacement is 7.2 liters.

The 8.3 liter is the Cummins C engine.

On edit: Someone PM'ed and asked about the torque/RPM-- that is 860 lb-ft at 1,440 RPM.

[et2]

Had three 5.9 and on my third 6.7. All have been in a Ram p/u except this one which is in our new 2103 Fleetwood Expedition 40x . Towing the toad we are at around 32500 combined. It is rated at 360 on this model with 800 or so of torque.

I've never had any power issues with any of them, and the MH is 42'. It pulls and drives just fine. We tow a Jeep Liberty at around 4500 lbs. I set it on economy on the trans and set the cruise and there isn't an issue. It hardly ever downshifts on the hills.

The Fleetwood Discovery is rated at 380 hspwr and 1000 on the torgue. I don't know how much bigger you need to go before a different engine is needed. I probably don't have the money for one of those MH's.

[randallb]

The 6.7 is usually combined with the Allison 2500 series transmission. The HP is 340 on most but there was a 325. Torque is limited to 660 to not stress the 2500. We had this combo in our 08 HR Vacationer 34PDD and loved it. 9.5 MPG and it always scooted right over the mountains on I-40. We always towed 2800#s. It usually would maintain 62 MPH which was our preferred cruising speed. On the 2 lane roads through the Appalachians it would always accelerated coming out of corners so that is all I could ask for. The variable geometry in the turbo also acts as the engine brake so there are no additional engine brake parts to fail. They also used the VG to limit initial take off torque so as not to strain the trans and driveshaft.
Randy

[pronstar]

The 6.7 is the smallest engine Cummins offers for MoHos.

More info here:
http://cumminsengines.com/motorhome

[Old-Biscuit]

Isn't the 330 CAT (8.3L) rated at 330 HP and 860 lbs. torque?

[Blaster_Man]

The 6.7 is a fine engine, but cannot handle the big and heavier DPs. If you are considering a larger DP with the 6.7, be sure to ask owners of the coach you like how it handles the weight.