Can't win

[Lonestar10]

115psi steers 110 drives 110 spread cheap Ironman steers i-607s. Yoko 703zl drives bridge r196 on spread. Truck is 11r22.5s trailer 296/75r22.5

[JimT]

(12-16-2019 )Lonestar10 Wrote:  Thought today would be awesome for milage.

80 West from Lincoln ne to Denver CO.

Doing 60mph
0 wind maybe 0-5mph
42000lbs - 2 counter weights 17.5 each and 1 40ft section of boom bout 13ft high.
Boost ruining 15-20 psi
Egts after turbo 600-650

Ugh things driving me up a wall other driver with 18 cascadia and same load doin 67mph getting 8 with dd15 and dt12 with 3.2 something gears

Last time I ran 80 west out to SLC I had horrible fuel mileage through NE too. I was just under 79k gross, had a mixed load of 3 LTL's: 6' high crated transformers at the nose, tarped, 4' high cubes of brick in the center, also tarped cus i'm paranoid about brick coming loose, and 2 nissan forklifts side by side on the tail, 8' masts, no tarps. Though what didn't help was an air dryer that went bad. kept running the compressor for long periods most of the way. finally pulled in to the TA in WY right before the scales, paid TA to pick up the part from a freightliner dealer ($150 cheaper then the Pete dealer who said he could get me one overnighted by tuesday...) in town since they didn't deliver on saturdays, especially at 6pm. changed it out in the parking lot and they let me discard the old one in their dumpster. Fuel mileage was better, but the drag from the load was horrible.

   

I love flatbed, but odd shaped loads and anything that sits above 6'6" high on my trailer just kills my fuel economy. That and my dpf...

[Lonestar10]

I got a question why is it some days when I do my cool down idle before shutting down the engine runs at 32-38 mg/stroke others it's 24-28. Outside temp doesn't seem to be a factor.

24-28 engine seems smooth
32-38 engine seems choppy

[Lonestar10]

Damn things are only a year old but I guess I did have one bad metering actuator that was my whole power problem for the last year so I suppose one of them could be bad because I can take the SOI up and down and it doesn't make the engine really run much different

[Lonestar10]

On quick serve there is a test to test the timing actuators but it requires unplugging one while the engine is running and if I remember right Rawze said that that could send the computer into a hissy fit that will never come out of

[Magard]

That’s like twice the mgs. Per stroke I’m running. Is common rail that much more efficient at idle. If engines good and warm I idle at about 10mgs. 12mgs after it cools down. Air compressor and ac make it go up another couple. That seems really high. I would be freaking if it was a 2250 that high at idle.

[Unilevers]

generally well tuned 871's tun in the 17 is range at idle.

[Lonestar10]

I see 34-38 way more than the 20s. With 725 RPM idle

[Rawze]

my cm871 bounces around in the 11 - 14 mg/stroke range all day when idling at 800 rpm. always has.

I have seen some guys be as low as 10 or so, and some up in the 18-24~ish... those are all normal in a de-mandated engine, or engine that is fully warmed up and is not trying to warm up the exhaust.

On a stock engine,.. its in the 28+ range after warmup and as much as 40+ at times when its keeping the exhaust cans warm (thermal management modes), but sometimes will drop for a while, then back up again when its fully warm in a long idle state.

One of the biggest factors is how tight the rings are in the engine. I can tell by hand if an engine is going to be a fuel pig at idle, or will be kind to its owner. -- How much carbon packing and buildup in the rings is the #1 differences. - its not really the actuators, or other things unless something is notably wrong with one... Engine does not even have to run real smooth, as long as it is not stumbling, etc.

One guy can have a really easy enigne to turn by hand (like mine, everyhting clean as a whistle well cared for, and well lubricated with gear lube), and the next, its 2x harder for it to be turned over, rings are tight, sharp on their edges, carbon packing, etc.... that or they have after-market piston/liner kit, or non-oem rod/main bearings, etc. and it has more friction.

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The common rail engines are NOT more fuel efficient than the CM871, -- not all at all, not one damn bit. - i have seen a few get really close with a lot of tweaking,.. but as a general rule,.. they are .1 - .3 mpg less fuel efficient even with all mods done..

I have only seen a few guys get their 2250's or 2350's up in the low-to-mid 9's consistently and those were guys running so light, that my prostar would be breaking 10's on the same loads.