Tystevens wrote:
I don't know if it lends anything to the conversation, but ...
I've towed the same trailer up the same hill with 2 different trucks: a 360 hp, 650 tq. Duramax, and a 365 hp, 420 tq. Ecoboost. Both are turbo charged, so the elevation loss factor isn't an issue. The Duramax had a 3.73 rear end, the EB has a 3.55. Both are 6 spd transmissions, but I don't know how the transmission ratios compare.
Heading east from SLC, Utah is the Parleys Grade on I80. It is about 10 miles long, with the last couple miles maxing out around 7% and fairly straight, so you can pull it with speed and not worry about corners. The top is 7100 ft. in elevation. With these conditions, it is a pretty good road to test pulling power.
Both trucks will pull the grade at 70 mph towing my 6500# TT; not floored, but neither had much left. The Duramax would typically downshift to 4th gear accelerating to after the last corner, and then hold 5th gear the rest of the way, the Ecoboost in 4th the whole time.
That is a perfect example for this discussion. It furthers my point above about a flat torque curve. The Ecoboost has a VERY flat torque curve compared to many other gas engines. It may not have the same max level of torque but spin the RPM's up half again faster and send it through a gear reduction and the torque curve at the wheels will look much like the Dmax truck.
Before everyone starts suggesting they are equivalent engines you have to consider fuel cost, long-term reliability, performance under extreme ambient conditions, duty-cycle (not miles but percentage of time running at or near max power output.
