2009 columbia detroit s60 14L bad mpg

I'm curious to see what you find out. Sounds like this truck is all over the place.

 

You and me both. After I get my Smart Shift upgrades, I'll be opening my wallet to the mercy of Detroit Diesel. I only see a 0.2mpg difference between running the same load down the same road at 58mph vs 68mph.

 

I don't think that 0.2 mpg difference is worth it myself. Seems to me like you'd make more on the extra miles run going 10mph faster.

 

What happened???....I'm running an '06 14L, my summer average was 6.4, in winter it's gone down to 5.4 and getting worse....also, how are you driving the truck? I'm mostly running heavy (40K +) and pulling a tri axle chassis (12K), speed is 60-65 but with a LOT of city driving lately....Seems from last winter and this winter (bought truck used in Nov '14) that this engine is VERY susceptible to cold.

 

I took my truck to WW Williams and ended up seeing better than 6.5mpg loaded (80k gross] for a while, but then my Vpod wore out and my turbo has been overspeeding with excessive shaft play. Back down to about 4.5-5.0mpg. Considering a funny motor at this point. Ugly fix did help a lot.

 

You guys are getting worse mileage than me and I have a CAT C15. I religiously keep track of fuel mileage,.. I believe its a good indicator of what condition the motor is in. I'm on my 3rd legal pad with which I've recorded every single fuel stop with location, price, gals and mpg since I've owned this truck. Thats how anal retentive I am about saving money. So many different things have a dramatic effect on the fuel mileage its often difficult to diagnose when mileage drops off.

Like you guys,.. I do see about .5 - .75 drop in MPG from summer to winter blend. Also,.. if you idle a lot,.. expect that to effect another .5 - .75 mpg. Since I stopped idling I've picked up .5 mpg just from that.

For me I get the most improvement from my driving habits. Watch my speed and RPM,.. keep it in the sweet spot. Try to minimize high boost PSI by feathering the pedal on grades and short shifting from stops.

I can easily run hard and fast. Truck can run 80 mph no problem. I used to run like that when I first got it. After watching half my settlements go to paying for fuel.. light bulb clicked and now I see dollar bills spewing out if I hammer down.

When I originally bought the truck I was lucky to see 4.5 - 5 mpg. Replaced 3 of the boost couplers, bought all new tires. 110 psi on steers, 100 in drives and raised trailer from 100 to 110 PSI (Trailer tires are 255/70 22.5 and are listed as 120 PSI cold) Had the over head done and replaced 3 injectors. This got me to 5.5 mpg. Later that year I had the ECM retuned from 435/1650 to 500/1850. Replaced my Davco with a new unit and replaced all my fuel lines. Combined with slowing down and a light pedal,.. that got me to 5.8 mpg with occasional 6 mpg on light loads. That was with 1.2 million on the motor. I had an inframe done last summer and now I am finally seeing 6 - 6.5 mpg. I dont think I can do any better with my set up than that.

Not sure for the 14L Detroit and how your Columbia is geared. On mine,.. 70 mph is 1550 rpm. 65 mph is 1400 rpm. 1375 - 1450 rpm is the sweet spot for my truck. Pushing 70 - 72 mph and my fuel mileage drops like a rock. At 70mph with anything over 70k gross,.. I barely see 5.5 mpg. If I push it to 72 - 75 mph,.. it drops to 4 - 4.5 mpg. I dont like to have to run that hard. Rather just cruise along at 65.. maybe push it to 70 - 72 before a long hill. For the most part I let everyone pass me by.

Hurst

 

My last years mpg was 5.28!!!!!! WTF!!!!!

 

I think with fuel prices going down the quality of fuel is getting worse, that and the winter blend. I lost close to 1.5 mpg since summer