A fuel efficient 3/4 ton? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

elwood · 04-26-2004, 09:44 PM

I have a '78 3/4 ton 2wd with a 350 backed by a 700R4 (both rebuilt). It currently has an edlebrock 1406 600 cfm carb on top of a performer intake, as well as headers and dual exhaust (with H pipe)

It's fast as hell, but the gas mileage I'm getting from this thing absolutely sucks.:p

What carb/ intake do I need to look at for better fuel economy? Should I go to a stock set up? The truck had all this fancy stuff on it when I bought it.

What else do I need to take in account to achieve better fuel economy?

I'm not looking to race or haul huge loads, It's kind of my daily driver.

Russell · 04-26-2004, 09:54 PM

Putting a Q-Jet on would probally help you out a lot as far as milage goes, but I have to admit, it cracked me up when I read "fuel efficient" and "3/4 ton" in the same sentance

87Silvy · 04-26-2004, 10:01 PM

Quote:

Originally posted by Russell
Putting a Q-Jet on would probally help you out a lot as far as milage goes, but I have to admit, it cracked me up when I read "fuel efficient" and "3/4 ton" in the same sentance

Yeah, I had a "Laugh Out Loud" moment also. :p

elwood · 04-26-2004, 10:04 PM

Yes, as I was typing that, I had a little chuckle myself!

Russell · 04-26-2004, 10:09 PM

Ah yeah, I love my 3/4 ton

Just need to get her a bit of a makeover

Chevy67Tk · 04-26-2004, 10:22 PM

Now don’t be laughing

I get almost 10 MPG with my 383 / 6-71 THM400 and 456 gears (you got to keep your foot out of it) and I’m happy about that. The 292 / 3 on the tree averaged about 8 MPG, just think after about 75 years I may have saved enough money in gas to pay for the engine. Ok not likely to happen the right foot gets a mind of its own.

Best thing I can tell you is keep the engine in tune the best you can, maybe change over to fuel injection. Tall narrow tires help, but an educated right foot is the best fuel saving device yet.

Destructo · 04-26-2004, 10:25 PM

Q-Jet will help, keep the intake, its good for fuel mileage. Really whats mainly killing for fuel mileage is the rear-end and the overall weight of the truck. I would also go to a better cam if its got stock one in it. I good cam for fuel mileage would probably be something like a XE262 or something and the proper cruise rpm would be good for mileage.

elwood · 04-26-2004, 10:33 PM

I believe it has a Comp RV cam. I'm serious, I keep my foot out of it, I'm not a speedster...OK, I admit, once in a great while, I'll have to show the local rice burners who's boss.

I always keep the truck in tune, plugs, rotor, cap,wires, timing, etc.

So I can keep the intake? Do I need an adapter to run a Q-jet? How much do I have to spend on a Q-jet?

cochran63 · 04-26-2004, 10:49 PM

I recently bought an 84 chevy 3/4 ton 4-speed and i rebuilt the 350 and it is getting aroung 18 mpg. I thought that was dang good considering my 85 swb 305 gets about 11 mpg.

85Silverado · 04-26-2004, 10:57 PM

I'm in the boat with Cochran...i get just about the same out of my '78

arveetek · 04-27-2004, 12:23 AM

Fuel effecient 3/4 ton? Then you want a diesel!

I average 19 mpg with my '81, and that's with 4.10 gears! If you had a 6.2L diesel, 3.42 gears, and a 700R4 with 31" tires, I guarantee you would see well over 20 mpg.

The worst mileage I ever get is when I'm towing my RV. I get around 12 mpg then.

ElGracho · 04-27-2004, 01:34 AM

Casey took the words out of my mouth...

My uncle has an 84 6.2 diesel 700R4 3/4 ton with 3.73 gears. 22 mpg empty, 16 mpg pulling a car on a trailer from San Diego to Portland OR.

Can't be beat...

southernmutt33 · 04-27-2004, 01:51 AM

ok who wants to trade htrer 3/4 350 for my 3/4 454....i get 8 mpg..my truck wheighs 5440 on the scales empty....i hate to see what kinda mpg i get when i put the 23 foot trailer behind it to go camping......but i dont think i could give my truck away with the price of gas......

but then again i like the BB in it for the pulling power....havent found anything yet i cant really tow or haul...so i guess thats what i get for haveing a truck i can use......

lost_66 · 04-27-2004, 02:35 AM

Hey everyone

you should get Fuel atomizer it will boost to 22 to 27 MPG!!
on 350!!

i had one in my 76 chevy pickup it goes 22 mpg

here infor more about fuel atomizer here link

http://www.fuelconcepts.com/

read it how it work!!

southernmutt33 · 04-27-2004, 02:42 AM

hmmm intersting...dont know any body who has one, i will look into it, but i hate to ask what they want for it......im thinkin on propane conversion....aint decided on that one yet.....

lost_66 · 04-27-2004, 02:45 AM

Propane is only keep clean inside of engine and emssiom that all
but cost per gallion same as normal gas at gas station $1,79 per gallion price same propane and gas mileage will almost same.. no differnt ....

Quote:

Originally posted by southernmutt33
hmmm intersting...dont know any body who has one, i will look into it, but i hate to ask what they want for it......im thinkin on propane conversion....aint decided on that one yet.....

southernmutt33 · 04-27-2004, 02:51 AM

figures....i was tryin to think of some way for better mpg....good thing i didnt buy this truck to drive every day....good thing is by the time i get rid of it, it will be a real low mile truck...after the tranny swap an new clutch, im gonna do a major tune up on it an see if that help....i need to tweak the carb to, maybe change it out if i can find a goood cheap used one........

southernmutt33 · 04-27-2004, 03:09 AM

the price isnt to bad....i sent them an email...if i can get betwen 2 an 6 mpg increase i would an will buy it....

lost_66 · 04-27-2004, 03:31 AM

yes you should try it!!!!!

http://www.fuelconcepts.com/

Grim Reaper · 04-27-2004, 10:25 AM

Quote:

Originally posted by Russell
Putting a Q-Jet on would probally help you out a lot as far as milage goes, but I have to admit, it cracked me up when I read "fuel efficient" and "3/4 ton" in the same sentance

No Joke. My FI 454 3/4 Burb gets 9.7 for normal driving. It gets 9.2 for towing 8k. It gets 11.5 empty no A/C. It gets 11. with A/C. It gets 10.3 towing 2500lb.

Now OD might get it a extra MPH but that's about it. I bought a $1000 Bomb honda that gets 28mpg. In fuel savings it paid for itself in 3 months. It also keeps the wear of our rig used for pulling the family camper. My wife now DD's that Burb. It goes between the house to the school and the Grocery and that's about it. Tank of fuel lasts over a month.

I been eyeing a bomb 6.2 3/4 burb that has a 4L80. Might squeak 20 mpg out of that empty and that's about as economical as it gets with a fullsize.

Grim Reaper · 04-27-2004, 10:42 AM

Quote:

Originally posted by lost_66
yes you should try it!!!!!

http://www.fuelconcepts.com/

That looks like a Snake oil type operation to me. Becides anything already built after 78 has that system on it. It's called a EVAP system. It burns the vapors off from the fuel tank. It does exactly what that thing does and GEEEE if it was that easy don't you think the auto manufactures would already have it because of the impending Doom our Government has put on them to raise MPG and lower emmisions?

Multi Port injectsion is the best way followed by Throttle Body. A well tuned carb is fine but it doesn't adjust for atmospheric changes.

If you want ot tune then instal a Airfuel gage so you can real time monitor what the engine is doing.

southernmutt33 · 04-27-2004, 01:42 PM

yup i agree with the snake oil concept......i emailed them an this is what they responded with

ok i got a 84 3/4 ton truck with a 454 4 spd granny tranny, an 4:10 or is it 4:11's.. Looks like a "hi-rev" engine on your hands. like what kinda mpg increase can i expect to get... It all depends on the way you drive. fuel system and driving habits. i only get 8 mpg now at 55 mph..if i can expect to get 2 to 6 mpg increase i would consider buying your product.... It is possible to get these mpg increases. http://www.agsint.com/atom.shl for more information.

they did not take the time to even write back....they just put in the answers from there web site....so i dont think i would buy their product....like ive said before i would like better mpg, but when i bought the truck i knew 8 mpg was probably the best i would get....so it really doesnt bother me....other than a tune up, im not gonna spend alot of money trying to get better....now if there was a couple of things i could do that would get me 8 to 10mpg more then i could see spending the money to do it.....i figure its the price you pay for haveing a truck.......

chickenwing · 11-10-2004, 02:49 PM

I'm allways lookin for an upgrade. Would be a bit more interested if there was a picture of the unit actually installed on a vehicle. Preferably a sbc.

*1FaastC10* · 11-10-2004, 05:30 PM

tune up (plugs, wires, cap, rotor, etc) and put a good tune on it, you should see a big improvment. my buddy has a 1 ton with 4.56 gears, TBI 350 and a TH400. he regularly gets 14mpg empty, and 11 with a trailer and his 1 tonned K10 on the back (around 6000# no including the trailer)

*1972C10* · 11-10-2004, 08:53 PM

My 85 Wieghs 5800 Now with a small block I get 11-15 depending on where and how i drive Highway mileage does better

It has a Mild 350 Th400 and 3.73 gears Haul anything i ever put behind it and will pass anything but a gas station

When i got it it had a 454 That thing got about 9 loaded empty didnt matter.

04-26-2004, 09:44 PM	#1
elwood Keep it gangsta! Join Date: Dec 2003 Location: Peoria, Arizona (Phoenix Area) Posts: 102	A fuel efficient 3/4 ton? I have a '78 3/4 ton 2wd with a 350 backed by a 700R4 (both rebuilt). It currently has an edlebrock 1406 600 cfm carb on top of a performer intake, as well as headers and dual exhaust (with H pipe) It's fast as hell, but the gas mileage I'm getting from this thing absolutely sucks.:p What carb/ intake do I need to look at for better fuel economy? Should I go to a stock set up? The truck had all this fancy stuff on it when I bought it. What else do I need to take in account to achieve better fuel economy? I'm not looking to race or haul huge loads, It's kind of my daily driver. __________________ 1984 K5 Blazer 305-NP208-700R4 Ex Police Unit It's old school, but moves along nicely... '78 C-20 - SOLD

04-26-2004, 09:54 PM	#2
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	Putting a Q-Jet on would probally help you out a lot as far as milage goes, but I have to admit, it cracked me up when I read "fuel efficient" and "3/4 ton" in the same sentance __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

04-26-2004, 10:04 PM	#4
elwood Keep it gangsta! Join Date: Dec 2003 Location: Peoria, Arizona (Phoenix Area) Posts: 102	Yes, as I was typing that, I had a little chuckle myself! __________________ 1984 K5 Blazer 305-NP208-700R4 Ex Police Unit It's old school, but moves along nicely... '78 C-20 - SOLD

04-26-2004, 10:09 PM	#5
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	Ah yeah, I love my 3/4 ton Just need to get her a bit of a makeover __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

04-26-2004, 10:22 PM	#6
Chevy67Tk Registered User Join Date: Mar 2003 Location: PA Posts: 349	Now don’t be laughing I get almost 10 MPG with my 383 / 6-71 THM400 and 456 gears (you got to keep your foot out of it) and I’m happy about that. The 292 / 3 on the tree averaged about 8 MPG, just think after about 75 years I may have saved enough money in gas to pay for the engine. Ok not likely to happen the right foot gets a mind of its own. Best thing I can tell you is keep the engine in tune the best you can, maybe change over to fuel injection. Tall narrow tires help, but an educated right foot is the best fuel saving device yet. __________________

04-26-2004, 10:25 PM	#7
Destructo Registered User Join Date: Sep 2003 Location: Lewisville, NC Posts: 1,836	Q-Jet will help, keep the intake, its good for fuel mileage. Really whats mainly killing for fuel mileage is the rear-end and the overall weight of the truck. I would also go to a better cam if its got stock one in it. I good cam for fuel mileage would probably be something like a XE262 or something and the proper cruise rpm would be good for mileage. __________________ 1985 Scottsdale Shortbed 4x4 Stout 350 with some "upgrades"-700r4-33x12.5" Mud Tires, Warn 8274-50 winch. 2005 Chevrolet Colorado Regular Cab 2wd 4-banger, 5 speed, Street Pack with 3.73 axle.

04-26-2004, 10:33 PM	#8
elwood Keep it gangsta! Join Date: Dec 2003 Location: Peoria, Arizona (Phoenix Area) Posts: 102	I believe it has a Comp RV cam. I'm serious, I keep my foot out of it, I'm not a speedster...OK, I admit, once in a great while, I'll have to show the local rice burners who's boss. I always keep the truck in tune, plugs, rotor, cap,wires, timing, etc. So I can keep the intake? Do I need an adapter to run a Q-jet? How much do I have to spend on a Q-jet? __________________ 1984 K5 Blazer 305-NP208-700R4 Ex Police Unit It's old school, but moves along nicely... '78 C-20 - SOLD

04-26-2004, 10:49 PM	#9
cochran63 Registered User Join Date: Jan 2004 Location: Oklahoma Posts: 1,057	I recently bought an 84 chevy 3/4 ton 4-speed and i rebuilt the 350 and it is getting aroung 18 mpg. I thought that was dang good considering my 85 swb 305 gets about 11 mpg. __________________ Youth soon passes away, but immaturity can last a life time.

04-26-2004, 10:57 PM	#10
85Silverado Registered User Join Date: Dec 2002 Location: Milwaukee, Wisconsin Posts: 198	I'm in the boat with Cochran...i get just about the same out of my '78 __________________ Paul D. '78 C20 Scottsdale 350ci 3 speed with granny gear 14 bolt rearend My trucks are "Car-Guy safe".......which pretty much means death trap in the hands of a normal civilian.

04-27-2004, 12:23 AM	#11
arveetek Ultimate Diesel Dude Join Date: Oct 2002 Location: Southwest Missouri Posts: 328	Fuel effecient 3/4 ton? Then you want a diesel! I average 19 mpg with my '81, and that's with 4.10 gears! If you had a 6.2L diesel, 3.42 gears, and a 700R4 with 31" tires, I guarantee you would see well over 20 mpg. The worst mileage I ever get is when I'm towing my RV. I get around 12 mpg then. __________________ Project truck: '81 C/20 converted to 6.2L TURBO DIESEL bored .040", gear drive, 6.5L injectors/pump, custom pistons, custom 4" exhaust, 700R4, 4.10's Daily Driver: '95 K1500 Tahoe, 6.5L TURBO DIESEL, NP241, 4L80E, 3.42's

04-27-2004, 01:34 AM	#12
ElGracho Gentleman Jim Driver Join Date: Nov 2002 Location: Poulsbo, WA Posts: 1,551	Casey took the words out of my mouth... My uncle has an 84 6.2 diesel 700R4 3/4 ton with 3.73 gears. 22 mpg empty, 16 mpg pulling a car on a trailer from San Diego to Portland OR. Can't be beat... __________________ Joe '75 GMC Gentleman Jim '84 Chev C10 Short Wide - Super duper plain (manual steering, manual brakes, no dome light, no cig lighter) '85 Chev C10 Short Wide - Super plain Vortec 4.8 4L60E trans also: '81 K30, '83 C30 Crew Dually, '84 M1028 CUCV, '85 M1009 CUCV, another '85 C10 SWB, '89 R3500 Flatbed

04-27-2004, 01:51 AM	#13
southernmutt33 Registered User Join Date: Mar 2004 Location: utard land, known to the rest of the world as utah Posts: 120	ok who wants to trade htrer 3/4 350 for my 3/4 454....i get 8 mpg..my truck wheighs 5440 on the scales empty....i hate to see what kinda mpg i get when i put the 23 foot trailer behind it to go camping......but i dont think i could give my truck away with the price of gas...... but then again i like the BB in it for the pulling power....havent found anything yet i cant really tow or haul...so i guess thats what i get for haveing a truck i can use...... __________________ if it aint got 4 wheels an a motor,its now worth talkin about...... if ya cant afford to buy it, then be hillbilly enough to build it, it's cheaper to build it anyway..... be a man, stand up to your women an tell them your the boss, an if she dont like that, then ask her if she needs help around the house... http://public.fotki.com/southernmutt33/ 84 GMC 454, 3/4 soon to be a dually with one ton suspension. 60 1/2, lwb stepside..for sale 98 taurus, ugliest body stlye ford ever built, but dependable family car. 73 vistaliner, cab over, newest toy, reason for turnin 3/4 into 1 ton

04-27-2004, 02:35 AM	#14
lost_66 Registered User Join Date: Nov 2003 Location: Pillager,MN Posts: 181	Hey everyone you should get Fuel atomizer it will boost to 22 to 27 MPG!! on 350!! i had one in my 76 chevy pickup it goes 22 mpg here infor more about fuel atomizer here link http://www.fuelconcepts.com/ read it how it work!!

04-27-2004, 02:42 AM	#15
southernmutt33 Registered User Join Date: Mar 2004 Location: utard land, known to the rest of the world as utah Posts: 120	hmmm intersting...dont know any body who has one, i will look into it, but i hate to ask what they want for it......im thinkin on propane conversion....aint decided on that one yet..... __________________ if it aint got 4 wheels an a motor,its now worth talkin about...... if ya cant afford to buy it, then be hillbilly enough to build it, it's cheaper to build it anyway..... be a man, stand up to your women an tell them your the boss, an if she dont like that, then ask her if she needs help around the house... http://public.fotki.com/southernmutt33/ 84 GMC 454, 3/4 soon to be a dually with one ton suspension. 60 1/2, lwb stepside..for sale 98 taurus, ugliest body stlye ford ever built, but dependable family car. 73 vistaliner, cab over, newest toy, reason for turnin 3/4 into 1 ton

04-27-2004, 02:51 AM	#17
southernmutt33 Registered User Join Date: Mar 2004 Location: utard land, known to the rest of the world as utah Posts: 120	figures....i was tryin to think of some way for better mpg....good thing i didnt buy this truck to drive every day....good thing is by the time i get rid of it, it will be a real low mile truck...after the tranny swap an new clutch, im gonna do a major tune up on it an see if that help....i need to tweak the carb to, maybe change it out if i can find a goood cheap used one........ __________________ if it aint got 4 wheels an a motor,its now worth talkin about...... if ya cant afford to buy it, then be hillbilly enough to build it, it's cheaper to build it anyway..... be a man, stand up to your women an tell them your the boss, an if she dont like that, then ask her if she needs help around the house... http://public.fotki.com/southernmutt33/ 84 GMC 454, 3/4 soon to be a dually with one ton suspension. 60 1/2, lwb stepside..for sale 98 taurus, ugliest body stlye ford ever built, but dependable family car. 73 vistaliner, cab over, newest toy, reason for turnin 3/4 into 1 ton



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04-27-2004, 03:09 AM	#18
southernmutt33 Registered User Join Date: Mar 2004 Location: utard land, known to the rest of the world as utah Posts: 120	the price isnt to bad....i sent them an email...if i can get betwen 2 an 6 mpg increase i would an will buy it.... __________________ if it aint got 4 wheels an a motor,its now worth talkin about...... if ya cant afford to buy it, then be hillbilly enough to build it, it's cheaper to build it anyway..... be a man, stand up to your women an tell them your the boss, an if she dont like that, then ask her if she needs help around the house... http://public.fotki.com/southernmutt33/ 84 GMC 454, 3/4 soon to be a dually with one ton suspension. 60 1/2, lwb stepside..for sale 98 taurus, ugliest body stlye ford ever built, but dependable family car. 73 vistaliner, cab over, newest toy, reason for turnin 3/4 into 1 ton

04-27-2004, 03:31 AM	#19
lost_66 Registered User Join Date: Nov 2003 Location: Pillager,MN Posts: 181	yes you should try it!!!!! http://www.fuelconcepts.com/

04-27-2004, 01:42 PM	#22
southernmutt33 Registered User Join Date: Mar 2004 Location: utard land, known to the rest of the world as utah Posts: 120	yup i agree with the snake oil concept......i emailed them an this is what they responded with ok i got a 84 3/4 ton truck with a 454 4 spd granny tranny, an 4:10 or is it 4:11's.. Looks like a "hi-rev" engine on your hands. like what kinda mpg increase can i expect to get... It all depends on the way you drive. fuel system and driving habits. i only get 8 mpg now at 55 mph..if i can expect to get 2 to 6 mpg increase i would consider buying your product.... It is possible to get these mpg increases. http://www.agsint.com/atom.shl for more information. they did not take the time to even write back....they just put in the answers from there web site....so i dont think i would buy their product....like ive said before i would like better mpg, but when i bought the truck i knew 8 mpg was probably the best i would get....so it really doesnt bother me....other than a tune up, im not gonna spend alot of money trying to get better....now if there was a couple of things i could do that would get me 8 to 10mpg more then i could see spending the money to do it.....i figure its the price you pay for haveing a truck....... __________________ if it aint got 4 wheels an a motor,its now worth talkin about...... if ya cant afford to buy it, then be hillbilly enough to build it, it's cheaper to build it anyway..... be a man, stand up to your women an tell them your the boss, an if she dont like that, then ask her if she needs help around the house... http://public.fotki.com/southernmutt33/ 84 GMC 454, 3/4 soon to be a dually with one ton suspension. 60 1/2, lwb stepside..for sale 98 taurus, ugliest body stlye ford ever built, but dependable family car. 73 vistaliner, cab over, newest toy, reason for turnin 3/4 into 1 ton

11-10-2004, 02:49 PM	#23
chickenwing Lovin' Life in Miss.! Join Date: Mar 2004 Location: Puckett, Mississippi Posts: 1,937	I'm allways lookin for an upgrade. Would be a bit more interested if there was a picture of the unit actually installed on a vehicle. Preferably a sbc. __________________ The truck... you hear that? No really, you did hear that?!!!

11-10-2004, 05:30 PM	#24
1FaastC10 Account Suspended Join Date: Oct 2002 Location: Elkhart, IN Posts: 6,400	tune up (plugs, wires, cap, rotor, etc) and put a good tune on it, you should see a big improvment. my buddy has a 1 ton with 4.56 gears, TBI 350 and a TH400. he regularly gets 14mpg empty, and 11 with a trailer and his 1 tonned K10 on the back (around 6000# no including the trailer)

11-10-2004, 08:53 PM	#25
1972C10 Account Suspended Join Date: Dec 2003 Location: Texas Posts: 2,686	My 85 Wieghs 5800 Now with a small block I get 11-15 depending on where and how i drive Highway mileage does better It has a Mild 350 Th400 and 3.73 gears Haul anything i ever put behind it and will pass anything but a gas station When i got it it had a 454 That thing got about 9 loaded empty didnt matter.

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