I learned the most regarding how to conserve fuel on grades by driving a truck that had a boost gauge installed and also had a digital display of real time mpg. The bottom line is that whenever possible keep the turbo boost at or below 50%.
The technique here is to use up to 50% boost on the downhill to gain speed, if you have a downhill. As you start climbing the hill you will find that in order to not go over 50% boost you will be easing off the throttle by millimeters at a time. It is possible to top out at 1000 rpm, which would not be recommended for the engine if you are at maximum boost, by easing off the throttle almost to the point of coasting it over the final rise. Let the start of the downhill do the work for you, don't press down on the throttle as you start down. Allow the truck to gain speed gradually with a minimal amount of boost, around 25-35%.
Using the same technique as #1, downshift when you hit 1100 rpm to get back to about 1500 rpm in the next lower gear. Again keep boost at a maximum of 50% and be easing off the throttle by millimeters as the speed slowly bleeds off. Sometimes you'll find an equilibrium in a lower gear that can sustain the climb with 50% boost.
On really long, steep grades it will be impossible to use techniques #1 or #2 without getting down to crawling in low range. Even then the mpg will be about the same as it would be if you go ahead and give it maximum boost in a middle gear. Bite the bullet and pull the hill with maximum boost.
After a while in your truck you will have a sense of whether you can use either #1 or #2 and at what speed you are targeting to top out, or whether you'll have to go at maximum throttle (boost) to get up that hill.
I tested driving like this on I-44 from OKC to St. Louis, with a lot of steep rolling hills. Each time was 79-80K with a dry van. First trip was max out the whole way, trying to fly down the hills and max boost uphill. In an older truck that resulted in 4.0 mpg. Next time I tried easing off a bit and got to 5.3 mpg. The last time I really carefully backed off the throttle up the hills, never getting above 50% boost except for a handful of pulls that required max boost. That resulted in 6.85 mpg. I was pretty amazed at the results. It's possible to save fuel on the hills if you stay off the stupid cruise control and learn how to free foot properly.
Hill climbing techniques
Discussion in 'Questions From New Drivers' started by Canuck-Truck, Sep 21, 2014.
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That is really good advice thank you. The thing is I don't have a turbo gauge installed. My engine is an international MaxxForce 13. I have heard many negative things about this engine first in the drivers room and now that I am paying attention to them I hear the complaints on the internet. Any specific advice when it comes to that engine or is the advice you give good for any all models?
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Conserve fuel in a company truck.....
I average 7.4 peddle to the governor. I just try to keep the Rpms near a steady 1400 and of the flashers have to come on then so be it and I enjoy the ride up.Canuck-Truck Thanks this. -
The harder you mash on the gas pedal against the floor [going up hill] the more power you get
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Like one of the other members stated I set the cruise control and enjoy the ride
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Set the cruise and let my smart shift do the work.
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HotH2o, Skate-Board and thejackal Thank this.
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Without a turbo gauge you might be able to achieve the same results if you have an mpg readout that gives either actual at the moment mpg or at least an averaged mpg with some kind of readout of variance. One bottom line is that if you can hear the turbo winding up, then you can start keying in the pitch. Another bottom line is to give it about half the throttle or less. -
EDIT: Actually......(and I've read enough of your posts to know you know what's up, so I'm sure you know this).......I never realized this until I drove a mechanical engine, and *I think* I'm correct when I say that the power you get out of a computer controlled engine isn't directly related to how far (or how fast) the pedal is mashed. I believe the computer has the final say in how much fuel is provided. You can only say "Computer, more fuel please". Computer thinks to itself "Be patient driver, I'll give it when the engine can use it. Until then you just sit there with yer foot on the floor and think you da man"Last edited: Sep 23, 2014
Lepton1, BROKENSPROKET, Hammer166 and 2 others Thank this.
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