The Big Three's New Diesels put on a Dyno

CumminsDriver wrote:


The GM Truck ran the hill in third gear, same as the other two. My DMax/Allison won't downshift until right at 2000 rpms.

Rich

I can't completely see the exact speeds they are going, but guesstimating it and plugging it into the rpm formula(RPM=(Axle Ratio x Vehicle Speed x Transmission Ratio x 336.13) / Tire Diameter) it looks as if they were in 2nd. I plugged in 33 inch tires. If they are actually 32 then it could have been third.
Although, I was just using 3rd as my example to explain to travelnutz what I was talking about.

The Ram was in 4th most of the way and did got into 3rd at the very end. You can tell by the gear number right next to the "D" on the dash with the Rams. The Ford was also in 4th most of the way until the very end. The gear they are in is shown in the tack.

If the GM was in third like you say, then that would mean that the GM actually had more torque multiplication versus the other two.

Ram
4th 1.00x4.10= 4.10

Ford
4th 1.14x4.10= 4.67

GM
3rd 1.41x3.73= 5.26