Thor Forums

[EA37TS]

Originally Posted by Chance

No doubt the 3-valve design allows the engine to breath better, particularly at higher RPMs. Ford specs show the 3-valve engine makes almost 20% more power in range of 4,000+ RPMs, but only about 10% more torque in the +/- 3,000 RPM range. My educated guess is that around 2,000 RPMs the difference in torque and power is even less.

In normal driving at around 2,200 RPMs in 5th, and +/- 3,100 RPMs after one downshift to 4th (comparing to Axis), the difference in torque and power between the two engines is limited to no more than about 10% or so.

The biggest difference by comparison is that large gasoline Class As can weigh 50% more than compact Class As like an Axis. That's why I'm hopeful that there is a little room to improve fuel economy slightly.

Two points

First, I did not mention that during my long weekend I ran the generator while travelling rather than use the inverter. I did this to keep the coach AC running. Also I was not towing a car.

Second, I use an App called Road Trip to track vehicle expenses and when I go back to look at the history on my Class C, last year I logged 6,077.2 miles and the average MPG was 7.83. That was a 31 foot Class C on an E450 chassis with the 305HP V10. For roughly 80 percent of those miles I was towing a Ford Fusion on a dolly.