2020 Freightliner vs 3500 GMC Dually at the Ike
Interesting outcome... Trailer: 18,500 lbs GMC Engine: 6.6 Duramax Brake Applications: 1 Time: 10:28 Freightliner Engine: 9.0 Cummins Brake Applications: 0 Time: 10:42 Link
Forum Discussion
4x4ord wrote:
You may be right but isn't it surprising that the 2015 Duramax out performs the 2017? I would have thought the turbo on the 2017 would pump more air and be capable of higher power with lower EGTs.
Not really, the 2015 may have had a more conservative tune that did not need to defuel/cut timing to keep EGT's in check. While a larger turbo can help reduce EGT's, there is still the DPF and SCR trapping heat and restricting flow. Outside temps also play a big role in EGT's and sustainable power as well. If the outside temps were a lot cooler with the 2015(which it looks like it was from the snow in the background) than they were in this test with the 2017, then the 2015 could sustain higher power levels without having to de-fuel/pull timing. If you really want to be surprised, the 385 hp 2014 Ram 3500 towed that same trailer that 2015 GM in the link you posted even quicker in 9:38( LINK ).
What a lot of people don't know is that just like a gas engine will pull timing and reduce power if knock is detected, so will a diesel if EGT's or other temps get too high.
