Drive easy for GPM now or drive harder for faster break-in?

[mwhals]

I have 2022 miles on my CTD now. I have been driving it easy and achieving a couple of MPG better than when I go the speed limit (I am 5 to 10 MPH below). Since I don't have anything to pull yet, I won't have heavy loads in it very often. The loads will be firewood when I get truck loads of it.



I think it might break-in faster meaning a quicker increase in MPG if I drive it at 70 MPH (speed limit) even though it hurts the wallet now. Of course I am realizing savings now based on driving 60 to 65 MPH. Which would be better for the long run?



Thanks,



Mark H

 

[JHardwick]

Driving 5-10 MPH below the posted speed limit puts you at greater risk of being in an accident and does nothing for the break in of your truck.

 

[MMeier]

Driving 5-10 MPH below the posted speed limit puts you at greater risk of being in an accident and does nothing for the break in of your truck.

Exactly what he said!! Need to get 15k# behind that truck and drive like no tomorrow!! These things were built to work , not lolligag around and be a hindrance to others on the road.

 

[jimnance]

Exactly what he said!! Need to get 15k# behind that truck and drive like no tomorrow!! These things were built to work , not lolligag around and be a hindrance to others on the road.

Yep, I had about 500 miles on my CTD and put about 16K fiver behind and drove it like I stole it over the mountains. She purrs like a kitten and gets 15-16 MPG average city/highway. Not bad considering it's a 4X4 Dually with an auto transmission.

 

[mwhals]

Driving 5-10 MPH below the posted speed limit puts you at greater risk of being in an accident... .

And speeding doesn't?



I drive that speed in low traffic times and by staying behind Semis. If I need, I do get up to 70 MPH (speed limit), however, I do not speed even in the car. I don't live in a highly populous area, so there is little traffic on the road compared to other parts of the country.



I only want responses about increasing the break-in of the truck.



Mark H

 

[DBond]

I think it might break-in faster meaning a quicker increase in MPG if I drive it at 70 MPH (speed limit) even though it hurts the wallet now. Of course I am realizing savings now based on driving 60 to 65 MPH. Which would be better for the long run?



Mark H

I think what you are asking is in the long run, 20k miles from now, which method would give you the lower total fuel useage. I don't think the higher speed is going to break it in faster.

https://www.turbodieselregister.com/forums/showthread.php?t=97121

Suggests running some mountain grades or with a light load. It seems getting a load on it and working it are good for the engine, even if that didn't improve mpg. I think your firewood loads would be a good start, if you are putting some miles on when doing that.



Safety vs speed; Small speed differences are handled all the time, slower vehicles include heavy trucks, RVs, exiting, merging, etc. On an interstate highway with light traffic passing is trivial, in heavy traffic speed has to be reduced anyway to maintain a safe following distance. Off of controlled access highways, you could come upon farm equipment, trucks pulling out, even a cow. Studies show small or no difference in accident rate over a range of +- 10 mph. Some of the more recent studies show lower rates at moderatly lower speeds. However, at slower speeds you will have greatly reduced injuries if you are in an accident. Traveling at 60 mph vs 70 mph you have 36% less kinetic energy, as this is the square of the vehicle's speed. The probability and severity of injury increases exponentially with vehicle speed.

 

[KParsons]

put your foot in it on all entrance ramps for a year or two . kp