Jumping off the Diesel Bandwagon - UPDATED

ib516 wrote:
With the 3.73s in the RAM 2500, it was a shockingly low 1500 RPM when cruising at 65 mph. I expect the 4.10s will be closer to 2k RPM.

Maybe someone can figure that out for me?

Here's the ratios for the 66RFE:
1st 3.231:1
2nd 1.837:1
3rd 1.410:1
4th 1.000:1
5th 0.816:1
6th 0.625:1
Reverse 4.444:1

The axle will be 4.10:1, and the tires will be 275/70/18s with a 33.15" diameter...

Given the short test drives I have done, on a truck with 3.73s, I'd plot the power curve like this (considering flooring it from a dead stop on an empty highway):
- Right off the line, it leaps ahead. The low (lower than my 48RE) 1st gear ratio of 3.23:1 and the gassers less laggy low end was noticable as compared to the diesel.
- After about 2000 RPM, where the diesel "lights up" due to turbo boost, the 6.4L felt a bit flat in comparison.
- Where the diesel is pushing strong is in the 2000 - 3000 RPM range, and the gasser felt like it was still building power. The diesel is ready to shift to a higher gear, and the gasser is just starting to push you back in the seat as it gets to 3500+ RPM.
- Then, at about 4000 RPM, the Hemi lights. From 4000 - 5500 RPM, it really feels strong - as strong as my tuned Cummins. I guess that makes sense because my Cummins is rated at 325hp for the factory and I have the Hypertech set on stage 2 which is about a 75 hp increase, for roughly 400 hp which roughly matches the 6.4L Hemi's output.
- The increase in power over 4000 RPM is quite noticable, maybe that's where the active intake runners and VVT change?

Of course I wasn't able to test it when towing a load, but I know it will do more shifting than the Cummins did.

Like I said - realistic expectations for a towing experience with 300 lbs-ft less tq.

Sadly, we still have a couple feet of snow here, so it'll be a few months before I will be able to give a towing report.

But you all know I've got OCD when it comes to checking fuel mileage, so I can do a report on that. I might even go get a pallet of shingles to load in the bed to test out the rear coils. If/when I do, I'll post pictures.