Driving tips to help a Cat C15 to be better on fuel.

Be glad you got a 3406b and hey look up how to turn um up you can pull some more power outta her pretty easily. Im in a 2016 prostar with my Dad hauling milk we were at 99,800 last night roughest ride of my life #### thing was hitting the stops and only got 5.3 and thats even after all the big hills were gone. the ol cat was getting 6.5 to 7 and that 379 rode great. This truck has a isx and a 10 speed and were having to drop gears on hills that we usta could pull without loosing a gear almost had to drop to 8th

 

3.5-4 mpg is good economy for B-trains. That 4.11 setup is going to suck back the fuel on flat ground if you want to go any faster than 55 mph. But it will rock the hills like a boss.

 

I just had a brain fart after re reading this thread about improving fuel mileage, which applies to Cat and Mack.
If any of you are old enough to remember what the go pedals were all about on those old engines you might have noticed that DD and Cummins had a similar feel, and Cat and Mack had a similar feel that I define as accelerator and governor.
If you were cruising a Cummins or DD and you came to a hill, you would have to push the peddle further and further until it found the sweet spot in order to maintain that speed, just like your car.
On the other hand, the Cat and Mack would attempt to hold that speed with no change in peddle, at least the Cat would, because the change in load was sensed by the governor and compensated to hold that rpm just like the engines in construction equipment, like built in cruise control, set the throttle or jam a screwdriver under the pedal and it would cruise.
Not much experience with Macks, but the Cats would hold their idle all night in real cold weather without speeding up or slowing down, without an MVS type air governor which the Cummins and DD needed to hold a constant rpm.
You had to drive them differently, less aggressive on the peddle getting up to speed, a slower squeeze, like there's an egg under your foot, not a sponge like in a Volvo.
If you ease the clutch and press the throttle to a position on the peddle that equates to 1600 rpm, that engine is going to go there as quickly as it is able, while if you moved the peddle the same distance on a DD or Cummins it wouldn't accelerate as violently, unless you floored it.
I noticed around 1996 the feel of the throttle on the individual electronic engines, some of the pedal characteristic had carried over from the mechanical engines, and if you drove them as you did the old engines, you got similar results economy wise by the way you worked the throttles.
I know that Cummins offers both throttle feels these days, or governing types, and I suspect others might but its not well known.
Would be interesting to know.

 

This was incredibly helpful as a driver accustomed to driving a cummins isx. Blew the rear diff in my w900 this week so I'm running my dad's t660 that has a cat c15 in it (blew up the factory Paccar at 1.3mil and had an old sterling in the yard with the cat that needed a head gasket so figured what the heck lol)
Long story short, the old man is 72 and is big on the "you'll figure it out" method.of learning so the parameters you set out are great for.someone like me who is still a rookie (5 years TDG tanker) but is a bit of an engine nerd who wants to know all their quirks for longevity and efficiency sake. So, thanks again!