In the quest for MPG who has thought of...

[idiabuse]

Aluminum two piece drive shafts?

Less rotating weight equals less energy used.

Have not spent the time yet to measure units from the junkyard.

Just wondering...




Javier

 

[stumiister]

I think GM used them on some of the pick ups but not sure what years.

 

[riotwarrior]

Aluminum two piece drive shafts?

Less rotating weight equals less energy used.

Have not spent the time yet to measure units from the junkyard.

Just wondering...




Javier

I think Prius owners have less rotating mass in their heads....does that count for mileage? I know prius weigh less so that can get better fuel economy but can't haul ***** either...

 

[icanfixall]

I'm not seeing how that would increase fuel mileage. But I'm ready to learn a thing or two. Run a narrow tire will increase mpg by redusing the resistance to rolling force needed to push the truck along. Adding some fuel additive like wmo or wvo. Then you can increase the mpg by your % choice. Running 80% wmo increases your fuel mileage by 80%. It only take 20% diesel to go the distance. Now if your trying to increase the mpg of whatever your running then you have to cut down the weight. Mels son got 29.5 mpg on straight diesel in the f150 they installed a 6.9 and a ZF 5 speed in. Short bed step side truck weighs around 3000 lbs I'm told.

 

[laserjock]

Reduce weight and reduce wind resistance and rolling resistance. Cutting the truck weight in more than half is a good start. Wow.

 

[Brad S.]

In the less weight area, I put my tailgate on scale once, it came in 70-75 pounds.
If a person doesn't carry much in the bed this could be taken off.
But then here we go with the tailgate up or down issue for mpg.(Mythbusters)
Also IIRC, if a pickup shocks are bad, they can affect mpg as well. (wheel bounce???)

 

[Hydro-idi]

Like stated above, I am not too sure this would be a good idea in regards to improving mpg. Seems like a whole lot of work to gain a 1/4 mpg. It may pay for itself in about 20 years . Yeah sure it would lighten up the drivetrain a tiny bit, but look at the trucks we are talking about. They don't really have good mpg written all over them. They are diesels made to haul/tow large amounts of weight to begin with. I would focus on properly inflated tires, maintenance, and remove any additional weight that is not needed in the bed.

 

[laserjock]

I am seriously considering putting my truck on a diet. Maybe the driver too.

Might get more off the driver.

 

[franklin2]

You guys noticed those new "skirts" they are putting under the 18 wheeler trailers now? I wonder what kind of difference they make? Though if you run thousands of miles a year, 1/4 mpg more would be a big difference I guess. Going with that same theme, you might get something out of a full length running board that goes from the front to the rear, and then add a rubber air dam to hang down low on the front. This of course would be for a 2wd road hauler type truck. I have seen a lot of duallys with those full length running boards. I am thinking the whole idea is to keep the air from going underneath the truck.

 

[TWeatherford]

I don't think you'd see a measurable difference, except in the weight of your wallet. If you wanted to eliminate rotating mass, consider the flywheel (if manual). A manual transmission flyhweel is really heavy, and takes a lot energy to spin it up and keep it spinning. Actually, it doesn't take that much, but certainly a lot more than a driveshaft spinning 2-3" away from its center of rotation. And if you don't already have a manual, swapping one in would be a good 1st step, as would lightening the whole truck. Then running narrow tires at full pressure. But most of us don't run these trucks for getting good mileage, or we'd all be in Jetta TDIs or at least anything but a 20 year old V-8 diesel with the aerodynamic profile of a brick.

 

[TWeatherford]

You guys noticed those new "skirts" they are putting under the 18 wheeler trailers now? I wonder what kind of difference they make? Though if you run thousands of miles a year, 1/4 mpg more would be a big difference I guess. Going with that same theme, you might get something out of a full length running board that goes from the front to the rear, and then add a rubber air dam to hang down low on the front. This of course would be for a 2wd road hauler type truck. I have seen a lot of duallys with those full length running boards. I am thinking the whole idea is to keep the air from going underneath the truck.

I think this is to reduce drag on the bottom of the trailer, and keep the trailer tires from having to break wind. But my understanding is that the only reason the vast majority of truckers have them, is not because of mythological mileage gains, but because Kalifornistan requires them because their lawmakers thought they were a good idea. Which would make me want to do just the opposite on principle alone.

 

[Jake_IN]

For a drive shaft the idea of it being hard to spin up i would consider negligible. The drive shaft isn't going to have a very high mass moment of inertia. Now as Tweatherford was saying the flywheel on the other hand does have a high mass moment of inertia. But as we all know that is needed in order to keep the engine running smoothly. Either way i feel the idea of reducing weight will have a much greater effect on mileage as opposed to loosing weight in order to reduce the MMO.


Although if someone gives me the diameter and weight of a flywheel i could calculate the MMO of the flywheel

 

['94IDITurbo7.3]

Why do people who drive 3/4-1 ton diesel trucks always complain about mpg? not bashing the OP or anything or saying he is complaining. i just don't get it. you buy a big ass truck to get the job done and do work. now say your towing a 5'er camper to a campsite. now yeah, i would wan't to get "decent" mpg, but if your camping budget is so tight that you are doing anything and everything to gain every ounce of mpg you can to save money, then how can you afford to go camping or even drive the big truck in the first place?


like i said, not directing this at anybody in this thread. it is just something that i notice when reading through the diesel forums.

 

[firehawk]

In the less weight area, I put my tailgate on scale once, it came in 70-75 pounds.
If a person doesn't carry much in the bed this could be taken off.
But then here we go with the tailgate up or down issue for mpg.(Mythbusters)
Also IIRC, if a pickup shocks are bad, they can affect mpg as well. (wheel bounce???)

Please don't take anything mythbusters does as science. Its just hollywood entertainment and their findings have been proven wrong.

 

[firehawk]

I think this is to reduce drag on the bottom of the trailer, and keep the trailer tires from having to break wind. But my understanding is that the only reason the vast majority of truckers have them, is not because of mythological mileage gains, but because Kalifornistan requires them because their lawmakers thought they were a good idea. Which would make me want to do just the opposite on principle alone.

The air deflectors were designed by JPL in wind tunnels and were proven effective.