Does pushing in the clutch while going downhill saves fuel?

I heard it it is better just to shut the truck off while going down hill and put in nuetral,, it saves fuel and power steering fluid/////LOL

 

Like trucker said focus on drivng. Keep it in gear!!!

"i took the life of some bodys loved one , but i saved 1/10 cent of fuel!! "

fubar!

 

Toot your horn
Toot your horn
Toot it all the way
Oh what fun
It is to drive
Laughing all the way
Hey!

Toot your horn
Toot your horn
Toot it all the way
Oh what fun
It is to run
In Georgia overdrive

 

Seriously, leave it in gear and do not push the clutch in, If you need to drop a gear and to slow the truck the trans needs to be meshing with the engine rpm. Engaging the clutch you prevent jake and have lost power to the drive tires. unsafe driving habits are only a recipe for disaster.

 

DON"T DO IT ! that's why they take off points on your driving test for coasting

 

Besides the mechanical damage, you are considered you don't have 100% control of the vehicle. Your computer records your coasting time by road speed and no throttle. They can see jake on but disengaged. Have a wreck and the DOT and lawyers will tear you apart.

Drive like you were taught, the truck is not a toy.

 

No, it doesn't save any fuel.

 

To answer your question directly and accurately: Yes, it can save you fuel. The heavier the load and the steeper the hill the more fuel you can save. Mountainous regions often have many downhills followed by an uphill. If you are going down a steep hill and you push in the clutch with a heavy load it is likely you see an increase in speed as much as 30 mph. If the road is straight and the road transitions smoothly into a steep uphill the increased speed and momentum will often help you coast a significant ways up the uphill or allow you to maintain tenth gear instead of dropping down to 8th gear at a high rpm range traveling at 35mph with your hazards flashing as is the case often times with a heavy load when keeping the engine and transmission engaged. To deny there is a fuel savings in this scenario is to simply state a claim that is untrue. So there is the correct answer to the question you posed.

Whether or not this is a good decision is another topic which you did not ask but pretty much every reply thus far has weighed in on as it being a foolish decision.

For one freewheeling is a practice that is illegal. If you are involved in a collision and it is found that you were freewheeling immediately prior to the accident there is going to be hell to pay. If there is a fatality in said accident there is a real possibility that you could serve jail time and/or have your CDL revoked. So there is the legal angle.

To be perfectly honest I am not a mechanic and can't tell you with any certainty how much if any damage is likely to occur to the transmission, engine, clutch, etc with this practice. I suspect many of the preceeding claims concerning damage due to freewheeling are based on heresay more than actual knowledge. Most of the posters on here are drivers not ACE certified mechanics. Do we as drivers not shift gears at highway speeds and do it hundreds of times each day? Aren't we supposed to push in the clutch while doing so? Sure most of us float all of our upshifts and some even float the downshifts but most manuals recommend disengaging the clutch on every shift. How much of a difference is there between pushing in the clutch for 1 second thousands of times a week versus pushing it in for 10 seconds at a time once in a while? I would imagine if you bring the rpms up to a level which match the speed of the truck at the time you re-engage the engine any damage would be very minimal if it existed at all as it would mimic a standard shift from one gear to the next but as I said I am not a mechanic but this would appear sensical to me.

The practice is deemed to be unsafe and it is understandable why especially for an inexperienced driver with a heavy load on a steep decline. Hopefully you would recognize these risks already as such risks should've been relayed to you in the course of your CDL training.

I will not recommend to you to do anything unsafe or illegal. Your question is akin to "will I make more money if I disregard the HOS rules, fudge my logbooks and drive 4500 miles a week?" The answer to that question is yes, 4500 miles x 40 cents a mile does equal a greater number than 2500 miles x 40 so sure you'd make more money provided you never got caught. So my straightforward answer to your question is yes, you can save fuel pushing in the clutch at times but it is against the law and can be dangerous.

 

If you read his question,

he ask nothing about uphill............

going down it will save no fuel..........

 

My guess is that savings is so insignificant as to barely be measurable...