Better Fuel Economy in the Cummins
#31
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Originally Posted by 6cylinders
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He got some good results from lowering the truck. I think that was his biggest gain. It was good reading I wish I would have book marked it.
He got some good results from lowering the truck. I think that was his biggest gain. It was good reading I wish I would have book marked it.
claimed 29mpg at 55mph. Had a box (don't remember) and injectors
and lowered 2 inches. I've always figured the lowering was a big
part of the mpg.
Tv just had a commercial for "on demand" karioki cable channel.
Gotta go barf.
Lowell
#32
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Originally Posted by sled4fun
It has been proven and said over and over that maximum mileage will be had with the tailgate in the UP position as opposed to the down position, use of net etc.
Originally Posted by sled4fun
I believe that a flat top cover over the bed rails gets you the best mileage of all.
Chuck
#33
Originally Posted by chuxtruk
Cmon....common sense says that drag is reduced by lowering the tailgate. Maybe some dipwit engineer or halfwit on TV would say something different but what would they know? I'm not buying it...
There was a respected test group that used several pickups, from little ricers to 3500's, using gate up, gate down, and those goofy net things.
They found most trucks got better mpg with the gate up or had no better MPG with it down or with a net.
The upshot was its pointless to bother dropping the gate or getting a net.
They did not do wind tunnel tests to find out why the gate up did not reduce MPG. They just found that having them up did not hurt MPG.
I can't say whether they were this or that, or engineers, but thankfully we have those types in this world or we'd still be using stone axes.
Big Jimmy
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Originally Posted by big jimmy
They found most trucks got better mpg with the gate up or had no better MPG with it down or with a net.
They did not do wind tunnel tests to find out why the gate up did not reduce MPG. They just found that having them up did not hurt MPG.
Big Jimmy
They did not do wind tunnel tests to find out why the gate up did not reduce MPG. They just found that having them up did not hurt MPG.
Big Jimmy
With the tailgate down, it just creates turblulence in the back of the bed which causes drage.
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Originally Posted by blord
The best that I can recall of the test, they said that with the tailgate UP it created a high pressure bubble in the bed. Wind then followed the contour of the bubble.
With the tailgate down, it just creates turblulence in the back of the bed which causes drage.
With the tailgate down, it just creates turblulence in the back of the bed which causes drage.
#36
Originally Posted by sled4fun
Exactly! It was an air bubble and the air flowed over it = less drag and better fuel economy. .
I'll whip out the "air bubble" like an old single action- after the appropriate ambush has been fashioned naturally. Or maybe DEADFALL TRAP would be a better description...thump.
Big Jimmy
#37
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I'm glad we have chuxtruk's "common sense" to live by. All the engineers and testers have been leading us astray! For years this has been talked about. And those Dodge wind tunnel guys will probably now be fired. Help, Im losing my balance.
Wetspirit
Wetspirit
#38
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Ok guys, I looked around a little to help enlighten us all on how these results were found related to airflow over the truck. Tailgate up or down.
Draw your own conclusions!
http://www.cartalk.com/content/colum...ctober/05.html
http://blog.kevindonahue.com/archive...s_mileage_.php
http://kwc.org/mythbusters/2005/11/e...s_cures_f.html
http://www.aberdeennews.com/mld/aber...e/14266948.htm
http://www.aberdeennews.com/mld/aber...printstory.jsp
http://experts.about.com/q/Dodge-777...efficiency.htm
http://www.trucktrend.com/features/c...tailgate_myth/
Draw your own conclusions!
http://www.cartalk.com/content/colum...ctober/05.html
http://blog.kevindonahue.com/archive...s_mileage_.php
http://kwc.org/mythbusters/2005/11/e...s_cures_f.html
http://www.aberdeennews.com/mld/aber...e/14266948.htm
http://www.aberdeennews.com/mld/aber...printstory.jsp
http://experts.about.com/q/Dodge-777...efficiency.htm
http://www.trucktrend.com/features/c...tailgate_myth/
#39
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I did kinda of an experiment over the last 2-3 weeks.
One week I ran 70mph for a week running cruise control to keep it at 70 or lower for a week and did about 13.5mpg and ran the tank to half a tank. Took a week to get to half a tank
Weeks 2 and 3 I ran 65mph and kept the cruise on when I could and ran the tank to half again....I was suprised to see the increase. 15.1-15.5mpg and 300 miles to a half a tank. Took a week and a day to get to half a tank.
Trust me it sucked driving 65mph, but if it saves me fuel, oh well for right now.
Bob
05 dodge ram QC 4x4 CTD Auto
One week I ran 70mph for a week running cruise control to keep it at 70 or lower for a week and did about 13.5mpg and ran the tank to half a tank. Took a week to get to half a tank
Weeks 2 and 3 I ran 65mph and kept the cruise on when I could and ran the tank to half again....I was suprised to see the increase. 15.1-15.5mpg and 300 miles to a half a tank. Took a week and a day to get to half a tank.
Trust me it sucked driving 65mph, but if it saves me fuel, oh well for right now.
Bob
05 dodge ram QC 4x4 CTD Auto
#40
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Originally Posted by IrishND
I did kinda of an experiment over the last 2-3 weeks.
One week I ran 70mph for a week running cruise control to keep it at 70 or lower for a week and did about 13.5mpg and ran the tank to half a tank. Took a week to get to half a tank
Weeks 2 and 3 I ran 65mph and kept the cruise on when I could and ran the tank to half again....I was suprised to see the increase. 15.1-15.5mpg and 300 miles to a half a tank. Took a week and a day to get to half a tank.
Trust me it sucked driving 65mph, but if it saves me fuel, oh well for right now.
Bob
05 dodge ram QC 4x4 CTD Auto
One week I ran 70mph for a week running cruise control to keep it at 70 or lower for a week and did about 13.5mpg and ran the tank to half a tank. Took a week to get to half a tank
Weeks 2 and 3 I ran 65mph and kept the cruise on when I could and ran the tank to half again....I was suprised to see the increase. 15.1-15.5mpg and 300 miles to a half a tank. Took a week and a day to get to half a tank.
Trust me it sucked driving 65mph, but if it saves me fuel, oh well for right now.
Bob
05 dodge ram QC 4x4 CTD Auto
#41
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Originally Posted by Wetspirit
I'm glad we have chuxtruk's "common sense" to live by. All the engineers and testers have been leading us astray! For years this has been talked about. And those Dodge wind tunnel guys will probably now be fired. Help, Im losing my balance.
Wetspirit
Wetspirit
#42
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Also don't discount the tailgate as a structural member across the rear of the truck bed.
I've seen reports of beds cracking at the welds due to running for extended periods with the tailgate removed, or with one of those cargo nets.
I've seen reports of beds cracking at the welds due to running for extended periods with the tailgate removed, or with one of those cargo nets.
#43
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Originally Posted by chuxtruk
Also when possible, if you're interested in the best mileage your truck could get, use your cruise control. It'll do a better job of saving fuel than your trust in your right foot, that's for sure. Especially on those freeway runs.
Made a round trip run to Pensacola Fl this past weekend and I got 22.58mpg on the outbound leg using the Cruise Control at 72-74MPH. Coulda got more if I kept it between 65/70mph but that wasn't fun.
Homebound leg had lots of stops, detours and town driving.. 20.5mpg.
The boost guage tells me if I'm getting good economy or not. anything below 5psi at 2000rpm = , 5psi = , 5psi+ = . Headwinds cost money. Hey!, it's a high profile chunk of steel being pushed through the air... Even brush guards deduct ~2mpg from what I've been told.
Did I say I love my truck? I love my truck...
It sure makes a great long-legged cruising vehicle. Easily getting well over 600miles on a tankfull. Daughter said my truck was quieter than my Wife's Minivan at highway speeds. (It helps to have it stuffed full of clothes too)
K.
#44
Follow someone
With all my vehicles I have found at highway speeds I get about three extra miles per gallon if I'm following somebody, at a safe distance of course, but the vehicle in front of you creates a little tunnel basically , where the wind is already agitated.
High divers use the same principle by smacking the water with flat Palms to create a tunnel and a smaller splash.
High divers use the same principle by smacking the water with flat Palms to create a tunnel and a smaller splash.
#45
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Resurrection:
I need to add that all these ideas and tests and opinions are all performed at very different conditions and with very different trucks and drivers...The best I have ever seen with my slightly modified 4x4 HO is just under 21 mpg, in Wyoming at about 5,000 feet above sea level running flat out to Colorado at 70 mph, little to no wind and after ULSD became the law for road diesel.
Limiting factors or drag adders= 2" level kit, larger "off road" tires, 350 lb cab hi canopy, tow mirrors, (can't remember if a/c or windows up or down...), standard load for a week out of town to include wife, luggage and a dog with supplies.
Drag reducers= Altitude, little to no wind added turbulence....level, slightly downhill running.
I worked with a guy that claimed his stock dually duramax regularly pulled 27-28 mpg. Also a 4x4.
I'm proud and in love with my truck still, but c'mon.... I am currently seeing 16.4, EZ on 1, don't break 70 mph 50/50 city/highway travel with slight fluctuation to average between fill ups, Power Service white bottle at .32 oz/gal, air check every weekend, at sea level, currently at 7950 gvw, winds variable, traffic light to moderate, temps 55-75F...
These kinds of threads make me glad we all don't live closer together.....
PS: The NV5600 is not an overdrive trans, 6th gear is the same ratio as 5th in an NV4500.... the "6th" gear is actually ratio'd between 2nd and 3rd for a 1,2,2.5,3,4,5 if you will, no overdrive.
I need to add that all these ideas and tests and opinions are all performed at very different conditions and with very different trucks and drivers...The best I have ever seen with my slightly modified 4x4 HO is just under 21 mpg, in Wyoming at about 5,000 feet above sea level running flat out to Colorado at 70 mph, little to no wind and after ULSD became the law for road diesel.
Limiting factors or drag adders= 2" level kit, larger "off road" tires, 350 lb cab hi canopy, tow mirrors, (can't remember if a/c or windows up or down...), standard load for a week out of town to include wife, luggage and a dog with supplies.
Drag reducers= Altitude, little to no wind added turbulence....level, slightly downhill running.
I worked with a guy that claimed his stock dually duramax regularly pulled 27-28 mpg. Also a 4x4.
I'm proud and in love with my truck still, but c'mon.... I am currently seeing 16.4, EZ on 1, don't break 70 mph 50/50 city/highway travel with slight fluctuation to average between fill ups, Power Service white bottle at .32 oz/gal, air check every weekend, at sea level, currently at 7950 gvw, winds variable, traffic light to moderate, temps 55-75F...
These kinds of threads make me glad we all don't live closer together.....
PS: The NV5600 is not an overdrive trans, 6th gear is the same ratio as 5th in an NV4500.... the "6th" gear is actually ratio'd between 2nd and 3rd for a 1,2,2.5,3,4,5 if you will, no overdrive.