Caterpillar MPG anecdotes

flat top w900l with a moose bumper and a 3406E @ 550/1850

Pulling cattle at 90k+ going 70+ 5.3mpg
Pulling reefer @ 80k and under going 62mph 6.8mpg

 

Slowing down helps a lot with non aero trucks as the slower you go the less your brick like aerodynamics hurt you. I was @ 5.7 in this same reefer operation doing 70 everywhere

I don't think Cats are inherently bad mpg engines though I think people just usually spec them for poor mpg applications.

 

I'll simplify this. I had a friend who ran several dump trucks. At the end of the day the ones that had CAT's always burned 25-30 gallons more than his Cummins equipped units. I can't imagine a Detroit not beating the CAT in that scenario if not winning the competition outright versus any engine.

Now another point. 550 hp engine is plenty with a c15 CAT. If you want reliability and longevity then 550 is what you need to be at. 800hp is fine and dandy but you definitely don't put a hired hand in that particular truck and for sure the old saying "if you want to play you gotta pay" comes to mind.

If you're good driving around like around like my grandmother did with eggshells under your throttle foot for a marginal fuel mileage gain in a 550hp CAT or something souped up even more have at it. But if you want to drive like a normal person and easily get good fuel economy, there's better options.

I love CAT's and if I'd still be driving my old 03 truck today with a slightly modified MBN if I hadn't foolishly gotten rid of it. But speaking from a bean counter standpoint, in his particular application, there are better choices.

c13 or c12? I'd pick a Detroit over either.

 

Depends on your CAT. C12 or 13. 3406E or C-15 or C15 Acert….or the old mechanical B or C. Flat nose as in cabover? Or an old hood?
Space between cab and sleeper? A lot, or average?

I run a 91 379 280 wheel base 63 flat top sleeper with a 3406C pulling my cow pot in the Midwest I’m at 4.8 always between 85-90k gross. Same trailer same weight leave southwest Missouri headed east to say PA I’m gonna get 5.5.

Hooked to a hopper loaded like a freight train I’ll get above 6.


I don’t drive the piss out of it. People hate my guts in a lot red lights or making a turn changing highways. I don’t see the sense in running a drag race it’s hard on my ####. I get it road gear then I do what I wanna do.

 

Again not disagreeing, if you reread my post i did point out the sweet spot for cats is at the high weight high power area and other engines stomp it most of the time for economy save in specific conditions I.E a 13 liter trying to outpull it at 80K and wont be a ton worse then the other 2 brands of 15 liters AT 80k. Their just not as bad as people make out either was more my point, especially as most people i know tend to try and compare the 600+ engines to the stock competitors.

As i said when you need power and torque but also want reliability there arent really that many other good options. The D60 is really the only true contender that comes to mind and even that one has some minor issues such as being well known that the only time a detroit doesnt drool is when its out of oil.

For light line haul stuff though pretty much anything beats a cat on a level playing field. My comment about C13s was specificly adressing that cats even at smaller sizes are only better when you expect to be max gross in performance but worse on economy as a rule SAVE very specific outliers like when competeing at 80k+ against a small 13 liter engine. Those little 13s gulp fuel trying to keep up when that heavy but sip when light. I should know i have a mx13 in a 579 and its only slightly better then a long nose flattop pete with a C15 in terms of mileage.

Hope that clears up my stance.

Edit: One afterthought. In your example of dumptrucks im going to assume they did a lot of city or stop and go driving? Cummins have always been better at stop and go then cat. So thats really going to hurt cats economy. I would asume from my own experince that on the highway the gap would be much smaller. Again i doubt they would be better but i do know the C-15s at a previous job only averaged around 2% worse then our ISX trucks and that was under normal driving loads. They were team trucks though and did a ton of highway with the only stops being fuel, trailer swaps, bathroom breaks and weather.

 

95 379 short hood 63 inch flat top 5ek set at 375 hp pulling flat bed in the Midwest. 4.5-7.5 depending on load and wind.

 

Heading west into the wind 4.5 to 5.5. Going east with a tail wind 6 to 6.5

 

I'll throw out some Detroit #'s. 98 T600 factory 500 not tuned. Run out west in the wind, as fast as legally possible +5.

Average 4.2-4.8 depending on wind. I never idle. But if you haven't run out west in the wind, you could underestimate it's affect on power and MPG.

Flat ground and a tall load north of Folsom, WY. Had the pedal to the floor on the old WIA, 47lbs of boost, and could not get past 1600 RPM. After driving several other high HP trucks loaded since then, I'd bet the old WIA was crankin in the 650-700 horse range.

My 500 now doesn't come close to the power it had.