I don’t think it is. In fact, the SRT’s report fewer reliability problems than the lower-HP Ram’s. If you’re within the design limits of the components, the increased HP is not going to have any first-order effect on reliability.
Yes but where in the rpm range are they making power? Trucks need low end power your car doesnt it works better with a more even power band.
You know, I thought you had a good thought there, so I did some reading up on this. It turns out the SRT 6.4L makes more horsepower and torque at EVERY RPM, not just up high. Apparently, the main issue was getting the truck to run on 89 octane, whereas the SRT requires 92 octane.
The SRT versions of that 6.4L Hemi run a compression ratio of 10.9:1, and the truck motor is dialed down to 10:1, and timing changed to allow it to run the lower octane fuel. This also resulted in a less-peaked HP curve, which creative marketing folks can call a “wider power band”, if you like. It’s really just making less HP and torque over the entire band, at all RPM.
Torque (lb-ft.):
Heavy truck 6.4L Hemi: 429 @ 4000 rpm
Light truck 6.4L Hemi: 429 @ 4000 rpm
SRT 6.4L Hemi: 475 @ 4100 rpm
I guess you could split hairs, and say the truck makes it’s maximum torque at an RPM just 2% lower than the car, but the car is actually making more than 429 lb-ft at 4000 RPM, too.
Power (hp):
Heavy truck 6.4L Hemi: 367 @ 4600 rpm
Light truck 6.4L Hemi: 410 @ 5600 rpm
SRT 6.4L Hemi: 485 @ 6100 rpm
Here, yes... obvious difference. In fact, I think the rev limiter on the trucks is set at 5800 rpm on the light truck version and 4660 rpm on the heavy truck version, so it’s just never going to build much horsepower (= torque * rpm / 5252).
I guess it mostly comes down to the almighty dollar, getting them to run on low-octane pump gas.