Road report
I had only partially tested the replacement 199 degree hydraulic fan speed controller up to now. Not full desert summer weather and grades.
Fixed that testing gap today. Went up Baker grade on I15 at 2pm and the worlds largest thermometer said 113 F.
Engine hit 215 in high gear at low rpm. 65? Mode on.
Mode off. Downshifted to 4th at 1800 rpm and the temp stabilized at 213. 58? Mph.
On level ground engine went back to 189. 109 outside.
Arizona and Utah have 75 and 80mph limits.
I was towing at 70 to 72 up and sometimes higher down hill.
Coach engine is at 8mpg.
Engine maintained small to medium temp rises on grades at those temps.
Very pleased as I have driven a lot of coaches in similar conditions. The m11 and the 199 controller did really well.
I could have motored up the grade much faster and ran the temp up more easily. But why stress things. Not late.
36,000 pounds combined.
I thought I could feel the difference in engines pulling power under loads with the fan on high at high rpms manually downshifting the trans versus similar grades at the same rpm but with the engine at 185 range.
Same pulling differences at low rpm with mode on and hot motor versus normal temps.
Subtle but noticeable if you are tuned into the test.