harmanrk wrote:
ib516 wrote:
I'll pay a 2-3 mpg penalty at the pump (for less expensive fuel mind you), for a bit less power and gain reliability, and avoid the OMG repair costs that are inevitable in any engine.
You 2-3 MPG loss may be a bit optimistic. Also, you definition of 'a bit less power' and mine are wildly different. (HPs may be close, but 400 ftLbs vs 900+ is not a bit less)
The 2-3 mpg is based on my 2007 5.9L Cummins 3500 SRW Megacab 3.73 truck and my 2014 2500 Crew cab 6.4L Hemi 4.10 truck pulling the same RV over the same route I took every summer. The Hemi got 7-9 mpg at 21k combined load, and the Cummins got 9-11 mpg. The lower number for both is into a headwind or in the mountains, and the higher is on the flats with very little to no wind. 2-3 mpg difference in my personal experience, and I tracked every tank with the fuelly app.
Interestingly, my current set up is also 8-10 mpg, and the RV is only 17 feet long and 3500# (but is a full 8 feet wide).
And yes, you're right, the torque gap is a huge, but I was speaking in terms of overall performance. I could crest the same mountain passes at 60 mph with the Hemi and a 12k RV as I could with the Cummins, but I used more RPM to do it. The overall performance gap isn't as wide as is represented by the torque figure. Like I said, the Hemi was faster to 60 mph with a 14k load than the Cummins was for whatever reason, part of that likely due to the 3.42 the Cummins truck had compared to the 4.10. But, like I said, similar overall performance, just higher RPM and more fuel used in the process.
