Diesel vs gas......................

BertP wrote:
They are not the same. Engine rpm to axle rpm:

Hemi: 3:1 * 4.1:1 = 12.3:1 overall ratio
CTD: 2.45:1 * 3.73:1 = 9.14:1 overall ratio

At max power rpm: (I believe that the Hemi develops its max power at 5000 rpm)

Hemi: 5000/12.3 = 406 axle rpm
CTD: 2900/9.14 = 317 axle rpm

That means that in first gear, the Hemi will be travelling 28% faster than the CTD if they are both at their max power point. Or, if we slow the Hemi down to the same speed as the CTD, it will be turning at just under 4000 rpm. How much power does the Hemi develop at 4000 rpm? Also, do both transmissions have the same effeciency rating at those rpm? Do the computers for either engine limit engine output in 1st gear?

You are looking for a simple answer to a complex question. The answer may be as simple as "marketing", I really don't know.

Bert

The only problem with that theory is that it means if you put a 3.73 RE into the Hemi truck, the overall 1st gear ratio would be closer to the CTD's (3:1 * 3.73:1 = 11.19:1 instead of the 12.3:1). Sounds good, but Dodge rates the Hemi with 3.73:1 RE even *lower* on GCWR (down to 15000 from 17000 for the 4.10:1 RE).

I can think of a MUCH simpler answer........We've eliminated all the other variables - truck platform, transmission, rear end.....the only difference is the engine.

Could it simply be that the CTD is a stronger towing engine than the Hemi? That doesn't mean that the Hemi is a "bad" engine for towing, just that the CTD is better at max weights........

And this isn't just a Dodge thing - GM and Ford do the same thing.....gotta be something behind it other than some conspiracy theory that the auto mfgrs are out to make the diesels look better.......