Higher Fuel Prices = Slower and Slower?

Don't confuse acceleration with momentum with acceleration via energy expended.
The greater the rate of acceleration the greater the energy needed to move the mass.
Resistance of the air mass becomes proportionately greater as the rate of acceleration increases.
Greater resistance requires greater energy to increase acceleration.
Ask yourself: Does your mileage go up, down or stay the same when you encounter a headwind? How about a tail wind?
Given equal parameters, it will always require more energy to accelerate an object to a greater rate with equal variables (terrain, angle of assent, atmosphere, etc)

 

yada yada yada....
Chicken butt say what ??
my brain hurts.....

 

I know I'm speaking as a new driver...but if you are going downhill, your mass is not carrying you, you are being pushed...and in a sence...falling. The OP is talking about fuel economy...more mass = more energy to gain momentum or even loose momentum. If you slow down on a flat run, you "should" use less energy and in turn save fuel. I think on hills, fuel econmy goes out the window.

 

To maximize fuel economy, run only as fast as required to make your destination on time.
Coast (in gear) at every opportunity, such as down hills..even if only a slight decline.
Accelerate gently. As if there is a rotton egg between your foot and the pedal.
Anticipate stops. Coast to the stop.
Don't rely on your jake to 'help' you stop in normal traffic operations. Save the jake for those declines (hills) where you will gain speed without acceleration.
Shift at lower RPMs. Each engine is different, however on flat terrain, I shift upwards between 1100 and 1200 rpm.
Don't run your rpms up if unnecessary.
Practice these tips and your fuel mileage will increase.

 

its aerodynamics and coefficient of drag. trucks are as aerodynamic as a brick. it takes a diesel engine more power and energy consumption to move the brick through the air at higher speeds because of drag. it has been found that 45-55mph is the sweet spot for the engines peak efficiency in moving the truck through the air by overcoming the weight(mass). less energy consumed=better mpg.

 

I am sure you are right but there have been times when I had to push a car that wouldn't start and when we tried to do it slowly we got really tired but if we ran faster then the car felt easier to push than going slower. Plus I have driven slowly on the interstate as a test before and my mpg didn't go up even a decimal point. Plus the road is never flat it always has hills and when you go fast you race up the hills even without giving it any fuel but if I go slow the second I hit the hill I am struggling to go up it. So in theory if the road is totally flat then I can see how slower is better for mpg but not the real world.

 

Use that cruise control..

On a truck the cruise will coast the truck down a hill and fuel it on the way up..if you gotta down shift..then you off the cruise on the way up...

figure out what your est speed is to the destination..say 60 mph..coast to 65 on the way down..let it coast as far as it will on the way up to 60..then fuel..

straight and level acceleration..put the egg under the pedal..works for big trucks..and 4 wheelers..

above all else..keep the engine in the torque curve where its most efficient

Petey

 

well the crappy thing is with the tanker if i set the cruise it wont over speed nearly like i need to get up the other side of the hill ...trust me if i do it i am hitting 7th gear on a not so steep grade ..on the floor i will drop to 9th maybe 8th ...so my theory the cruise is use less in hills ... idc about the stupid bonus really ... i mean i avg maybe 4.5 mpg in the hilly and mountain areas way it is ... i hammer down cuz its to darn time consuming if i dont ... i never hear anything about it form the company they know how it is when ur in the hills ...but flat lands i do decent and still get about 6-7 mpg on cruise usually

 

One thing noone ever seems to consider is by running a little faster you have opportunities to haul more loads. Say I run 60 mph in a 10 hour day thats 600 miles, at 70 thats 700 miles. Take that times 7 days and I was able to run an additional 700 miles you could have run.

I know those numbers are not exactly the miles you can put on due to delays etc.. but its for keeping the math easy.

I know you will save money by slowing down and I see the numbers guys post like 10-15k fuel savings per year and I completely believe that number. They don't take into account that you could make a portion of that up by increasing the amount of freight you could haul in a year.