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The Jonesy
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77 Posts
Discussion Starter #1
I have a 2003 RCSB with the 4.8L in it and i have noticed that the 6 months i have owned it, it seem to get really crappy gas mileage or at least alot lower then i thought it would when i bought it. What does everyone elses 4.8s get and this is a compltely stock truck for now lol
 

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GMFS Military Member
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10,899 Posts
im only getting 14-15ish but thats with 37s and 3.42s..Hopefully itll go up a little when i go to 4.88s
 

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HOT AIR BALLOON OWNER
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14,932 Posts
Crappy is what to you? 15-17 average?
 

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The Jonesy
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77 Posts
Discussion Starter #6
yea im like 15-17 at best and its 2wd and stock wheels and tires, and that is staying out of the gas and driving normal, i just expected better i guess cause my old 96 4x4 long bed got alot better then this :(
 

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jesus marian hossa
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1,032 Posts
that's about what i get. i do about 21 on the highway at 65 though.
 

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The Jonesy
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77 Posts
Discussion Starter #8
i should just upgrade to a 6.0l cause when i tune and put headers and exhaust i will get worse then that lol
 

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HOT AIR BALLOON OWNER
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14,932 Posts
i should just upgrade to a 6.0l cause when i tune and put headers and exhaust i will get worse then that lol


In the city? Probably not, it'll be more efficient. More than a few people have gotten 20-23 freeway with 6L swaps.

It's a truck, don't expect 30mpg from it combined. 14-17 is reasonable, and the 4.8 will be worse city as it doesn't have the torque down low.
 

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Registered
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2,552 Posts
Jameson, i cried a little bit.

I didnt realize u had a 4.8

I mean that in the nicest way possible
 

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GMFS Military Member
Joined
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10,899 Posts
Jameson, i cried a little bit.

I didnt realize u had a 4.8

I mean that in the nicest way possible
tis true :nono: i need a VMAX or 6.2L in my life..:hmm:
 

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The Jonesy
Joined
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77 Posts
Discussion Starter #13
Yea im not expecting to get 30mpg but im i would like to get like 20 or 22 on the highway and would be more then happy with 17 or 18 in the city lol, i am deff looking at the blackbear tune and full exhaust, and maybe gears but i dunno about them yet, what do you think those would improve with real world numbers to?
 

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GMFS MoPar/Air Force Crew
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5,457 Posts
My 4.7 gets 22 :shrug:

Go MoPar :anitoof:
 

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Kit, What Kit
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188 Posts
I would do gears first if I were you.
I don't know why they put such high gears with a short stroke motor.
 

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GMFS Military Member
Joined
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10,899 Posts
Yea im not expecting to get 30mpg but im i would like to get like 20 or 22 on the highway and would be more then happy with 17 or 18 in the city lol, i am deff looking at the blackbear tune and full exhaust, and maybe gears but i dunno about them yet, what do you think those would improve with real world numbers to?
all of that and less pedal, but itll be pricey and prolly wont pay itself off in fuel savings for a while
 

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The Jonesy
Joined
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77 Posts
Discussion Starter #17
yea it will take alot of miles to pay it off but i have to spend my money on something i guess lol and yea i dont know why either and i need to find out what gears it has in it, whats the easiest way to find that out?
 

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Registered
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2,525 Posts
i get right around 21 with my reg cab stepside...nothing to horrible.
 
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