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Discussion Starter #1
Right now I have a 99 single wheel automatic, and i'm looking into trading it for a 01 Dually with a five speed.
How would the fuel economy on the dually be compared to my single wheel which gets 15.
 

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I personaly haven't seen much difference in mpgs between the two. If anything, it might average out to a 1mpg decrease for the dually. But, all of these trucks are different and you might even gain. Who knows.
 

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if your doing lots of heavy towing you cant beat a dually. major cons: extra unsprung weight, harder to cram in parking spaces
 

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Rear end gears make all the difference.
 

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I get between 19 and 20 MPG. :thumbsup
 

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Discussion Starter #6
i know the dual wheels usually take it down a bit but i figured it would make up for it with a five speed
 

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i know the dual wheels usually take it down a bit but i figured it would make up for it with a five speed
I was thinking the exact thing thing, any decrease from the duals should be made up and then some with the 5 speed. Also like said above... rear end gears will be the real determining factor
 

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2 more tires to replace
 

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I run between 19 and 20 highway, 15 to 16 around town and 11 towing 14 k fifth.

Bill
 

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i can get 19 to 20 all day long running 70-75 and usually 16 around town if i would quit with all the smokin.
 

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I get about 19-20 on the highway if I keep it between 65-70 with a dually
 

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you only get 15mpg with your SRW? I get like 18 in traffic, 22ish on highway if I dont go over 80.
 

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you only get 15mpg with your SRW? I get like 18 in traffic, 22ish on highway if I dont go over 80.
he also has a 24v not a 12v. and his looks like a 4wd unlike your 2wd.
 

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I've gotten up to 23... on my way to detroit. then I got a new turbo and couldn't help myself the whole way back and got 17.... it averaged around 21 back and forth to school though running 55.
 

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my 4x dually auto gets 19+ lightly loaded... 60-65 mph...
 

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I would guess that you lose about 2mpg, with the duals, and perhaps more with bigger tires, but you can make that up with a stick by keeping the rpm down and the load up. I can get over 19 as I have hit just under 19 on a tank, but mine's tuned for fuel efficiency. Add more fuel, and keep it at a lower rpm, and you will do better.

Having said that, I would note that any comparison to a six speed should be taken with a grain of salt as the eth engine in the six speed is higher compression (17:1 vs 16.5:1, if I remember correctly) than the etc engine ahead of the nv4500 and auto, and will give differing results. There are other various differences as well.

By the way, 4" exhaust will save you 1.5 to 2 mpg, which will EASILY pay for itself in 15-30k miles depending on your choice. Before the fuel prices skyrocketed, I estimated 30k for my ss 4" exhaust. More fueling at a lower rpm adds another 1.5 to 2mpg if you drive appropriately for fuel efficiency.

If you don't mind driving a boat, I would say do it. But I am a little biased. I don't care for autos, especially behind a diesel.
 

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Last filll up i got 14.65 hand calculated with a mix of highway and city driving. Did go at it with a couple of powerstrokes so im sure that didnt help the milage. I dont think the 4:10's help at all either
 

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You may improve mileage. I get over 20 something on the highway and I have the auto and 4x4.
 

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I don't know about a compression difference... don't they all have the same bore and stroke, pistons and heads
 
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