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#26 |
Registered User
Join Date: Jun 2007
Location: Cape Coral, Florida
Posts: 1,123
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Re: Dont take this as ignorance but as gaining knowledge
my 86 swb with 305/700r4 and 2.73 gears got 17mpg on its last tank of city and highway driving.
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1986 Custom Deluxe 10 1978 Caprice 2 door - sold 1937 Chevrolet 2 door sedan - project |
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#27 |
Registered User
Join Date: Feb 2012
Location: Lynd, Minnesota
Posts: 201
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Re: Dont take this as ignorance but as gaining knowledge
I guess if I was building a truck just for fuel economy, I would do electric fans, a ram air intake from Spectre, electric water pump, 700r4, 3.08 or 2.73 rear, headers, dual exhaust, synthetic oils, HEI distributor, better spark plugs, some sort of fuel injection, and probably lower it. I'd make sure the motor has good compression too.
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Semi professional heavy equipment operator Amateur mechanic |
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#28 | |
Registered User
Join Date: Jul 2011
Location: SW Ontario
Posts: 1,204
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Re: Dont take this as ignorance but as gaining knowledge
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#29 | |
Registered User
Join Date: Mar 2012
Location: San Diego, California
Posts: 110
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Re: Dont take this as ignorance but as gaining knowledge
Quote:
i got a 468 engine and she dont drink she gulps!
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2001 Tahoe 1978 K30 |
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#30 |
BAD BOW-Silverado XST
Join Date: May 2000
Location: Senior Member from Austin, TX
Posts: 6,431
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Re: Dont take this as ignorance but as gaining knowledge
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#31 |
Registered User
Join Date: May 2010
Location: laurel hill Fl
Posts: 645
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Re: Dont take this as ignorance but as gaining knowledge
Mine is a 305/700r4 2.73 gears. I rebuilt my carb and leaned it out a little. I've completely changed my driving style. low back pressure pipes. solid smooth acceleration to speed. use engine braking to plan stops. If you keep off the brakes it will do wonders for your wallet. I went on a 1400 mile round trip and averaged 26mpg mostly going 75-80. however around town i get 16 or less. highway towing with a heavy travel trailer 14-15mpg. The a/c compressor in my truck will burn almost twice as much fuel; feels like i'm towing a load when i turn it on.
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1985 C10 Custom Deluxe LWB 305/700r4 [ Goldfinger ] ![]() 1999 k3500 crew cab dually 6.5tdi/4l80e |
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#32 | |
Registered User
Join Date: Aug 2009
Location: hillborough nc
Posts: 410
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Re: Dont take this as ignorance but as gaining knowledge
Quote:
Well the biggest part of fuel econ is how you drive no jack rabbit starts and no poking off the line drive with sense. A few other things I would try is a block heater, I am the kind of person I hate to race a cold engine its the way my dad raised me so I let mine warm up for at least five minutes before I leave the house and that really hurts mileage, but if you install a bock heater in your truck and have it on a timer where it cuts on at like 3 hours before you leave for work, school or where ever. Also with a block heater your engine can run more efficiently sooner. Next would be an electric fan but they are a little pricy and wiring up a relay has always confused me. If you have a clutch fan check and make sure it’s not locked up, and if it is replace it. Engine tune is also very important. My 77 you mash the gas once and touch the key and it is running no extra fuel wasted in the starting process. when my dad gave me the 77 in my sophomore year of high school it was in poor sate of tune I was getting about maybe 8 at the most, I added true duels with turbo mufflers and adjusted the carb set the timing replaced plugs, wires, cap and rotor, pcv valve the little breather for the pcv valve, new k&n air filter and it was capable of like 12 mpg but now it ran really good and I kept my foot in it a lot. one more gear syndrome, we have 3 trucks that suffer from "this truck feels like it needs one more gear" at the Huskey house hold my k10 and dually have 4.11's and my big ten has 3.73 gears all three trucks will pull like a hoss but fuel econ suffers when I restore my 77 big ten I plan to add an overdrive unit in front of the stock granny gear to get my rpms down on the highway. so if you can get your rpms lower it can help your mileage you kind of want a good balance of low rpm and torque in your cruzing rpm range engine rebuild, there is no doubt in my mind that a rebuilt motor will get better mileage than one with 200,000 miles, my current project is a 79 Chevy with a 250 3ott and 3.08s in the back and its good for about 16 mpg on the highway but the engine is warn out so I found a non integral 250 we put slightly larger valves with a 3 angle valve grind and had .040 milled off the head so we have an improvement in air flow through the head and a little more compression, as for the block it will stay all stock except for a slightly larger cam. Everything we have put into this engine is to make it more efficient is if you do decide to overhaul your engine keep it fairly stock for best mileage results Power steering is not designed to eat up much more than about ½ of a horse power but if your die hard set on getting another mpg you can always put manual steering on it Tall skinny tires like mentioned before can help mpg, avoid low rolling resistance tires because they can cause you to have longer stopping distances and that’s not safe
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77 chevy BIG 10 350/sm465/12bolt w 3.73 bout 240 horse power NO power steerin 79 chevy 1/2 ton 250/three on the tree/3.08s soon to get built 250/floor shift conversion/3.08s 81 mercedes 300d 25 MPG 77 chevy BIG DOOLEY 454/sm-465/14 bolt 4.10s "fully loaded" 73 plymouth duster 225 slant six/230 3 speed/8 1/4 trying to acheve 300 horse six http://www.cardomain.com/ride/3135091 '77 chevy trucks. built to stay tough. life is short build a hot rod ![]() |
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#33 | |
Registered User
Join Date: May 2011
Location: Goliad, TX
Posts: 672
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Re: Dont take this as ignorance but as gaining knowledge
Quote:
Can you list the modifications done to help increase fuel economy? Did you lower your truck? Any aerodynamic mods? I know that kind of amazing fuel economy took some work to obtain.
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1990 ¾ ton 4x4 Chevy Suburban -Cummins Diesel - 12 valve - factory rebuilt -6 speed bullet proof manual transmission - NV5600 -Gear Vendors Overdrive - HX35 Holset Turbo -NP205 iron transfer case -3.73 gears -2" Lift |
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#34 | |
Canadian Trucker
Join Date: Nov 2010
Location: Sarnia, ont canada
Posts: 648
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Re: Dont take this as ignorance but as gaining knowledge
Quote:
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#35 |
Just here to tinker
![]() Join Date: Jun 2008
Location: Holland, MI
Posts: 3,692
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Re: Dont take this as ignorance but as gaining knowledge
Honestly, overdrive I think is the answer here. I have 3:73's but when I am in overdrive (Gear Vendors), my final drive ratio is 2:91. This is the best of both worlds because you still have low end grunt to tow and get off the line, but on the highway, you can relax the RPM's and sip the fuel.
However, I realize the cost of GV these days would take forever to pay back in mileage gained. You could buy a cheap Toyota Corolla that gets 35 MPG for less than you could buy a GV.
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78 C10 SWB Diesel #1 (wrecked)http://67-72chevytrucks.com/vboard/s...1978+silverado 78 C10 SWB Diesel #2 (sold)http://67-72chevytrucks.com/vboard/s...d.php?t=650751 60 GMC Suburban (sold)http://67-72chevytrucks.com/vboard/s...d.php?t=445526 60 GMC 1000 (sold)http://67-72chevytrucks.com/vboard/s...d.php?t=298235 67 GMC 1500 (sold) http://67-72chevytrucks.com/vboard/s...d.php?t=803695 86 Suburban(summer unit) http://67-72chevytrucks.com/vboard/s...d.php?t=810697 88 Suburban 4x4(winter unit)https://67-72chevytrucks.com/vboard/...25#post8900725 |
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#36 | |
Registered User
Join Date: Feb 2012
Location: Lynd, Minnesota
Posts: 201
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Re: Dont take this as ignorance but as gaining knowledge
Quote:
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Semi professional heavy equipment operator Amateur mechanic |
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#37 |
Account Suspended
Join Date: Apr 2009
Location: hazard, ky
Posts: 1,674
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Re: Dont take this as ignorance but as gaining knowledge
700 is a four speed 4th gear is od
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#38 |
Registered User
Join Date: Feb 2012
Location: Lynd, Minnesota
Posts: 201
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Re: Dont take this as ignorance but as gaining knowledge
I worded that weird, but I meant it that the 700r4 is essentially the same as a th400, but it has an overdrive (4th gear)
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Semi professional heavy equipment operator Amateur mechanic |
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#39 |
Registered User
Join Date: May 2010
Location: laurel hill Fl
Posts: 645
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Re: Dont take this as ignorance but as gaining knowledge
Luckily the 700r4's low 1st helps me get moving. If i wanna push it i can hit 0-60 in around 9 seconds, But doing "ANY" of that brings it way down. Before i rebuilt my carburetor it was getting 8.
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1985 C10 Custom Deluxe LWB 305/700r4 [ Goldfinger ] ![]() 1999 k3500 crew cab dually 6.5tdi/4l80e |
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#40 | |
Registered User
Join Date: May 2011
Location: Goliad, TX
Posts: 672
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Re: Dont take this as ignorance but as gaining knowledge
Quote:
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#41 | |
Registered User
Join Date: May 2009
Location: Motor City
Posts: 9,194
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Re: Dont take this as ignorance but as gaining knowledge
Quote:
The frontal area is the "projection" from the top of the truck all the way to the ground (like the hole it would make if you ran it through a wall). Dropping the truck down reduces the front area, which is a term that is squared in the coefficient of drag equation. K
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Chevrolet Flint Assembly 1979-1986 GM Full Size Truck Engineering 1986 - 2019 Intro from an Old Assembly Guy: http://67-72chevytrucks.com/vboard/s...d.php?t=342926 My Pontiac story: http://forums.maxperformanceinc.com/...d.php?t=560524 Chevelle intro: http://www.superchevy.com/features/s...hevy-chevelle/ |
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#42 |
Registered User
Join Date: May 2009
Location: Motor City
Posts: 9,194
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Re: Dont take this as ignorance but as gaining knowledge
BTW - my '87 is a 4.3L V6, 3.73 axle with a .73 overdrive, P235 tires - gets between 20 and 22 mpg most days (70 mph).
K
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Chevrolet Flint Assembly 1979-1986 GM Full Size Truck Engineering 1986 - 2019 Intro from an Old Assembly Guy: http://67-72chevytrucks.com/vboard/s...d.php?t=342926 My Pontiac story: http://forums.maxperformanceinc.com/...d.php?t=560524 Chevelle intro: http://www.superchevy.com/features/s...hevy-chevelle/ |
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#43 | |
Registered User
Join Date: May 2011
Location: Goliad, TX
Posts: 672
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Re: Dont take this as ignorance but as gaining knowledge
Quote:
On my 1982 Suburban (6.2L diesel, 3.08 gears, stock heigth), it only gets 24 mpg at 70 mph. If I reduce the speed down to 55 mph, I have seen fuel economy as high as 30 mpg. I'm sure that if I slammed it, high speeds would not make such a difference.
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1990 ¾ ton 4x4 Chevy Suburban -Cummins Diesel - 12 valve - factory rebuilt -6 speed bullet proof manual transmission - NV5600 -Gear Vendors Overdrive - HX35 Holset Turbo -NP205 iron transfer case -3.73 gears -2" Lift |
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#44 |
Registered User
Join Date: Jul 2009
Location: washington
Posts: 4,178
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Re: Dont take this as ignorance but as gaining knowledge
Alright I'd I was going to fry an egg with a magnifying glass here's how I would do it
The trucks are basicly going Down the road like the broadside of a barn. 1.lower it as far as you can. 2. Get rid of the weight. No sway bars no tail gate 3. Tonnue covers may or may not help. What does is a tailgate net 4. A/c looks great in the recycle bin.- less weight 5. We have grandma steering. Get rid of the power steering. Been driving this way for three years steering effort isn't bad an you finally get feedback 6. Kill all emissions equipment 7. Electric fans don't kill hp 8. Aluminum bumper brackets 9. Fiberglass hood 10. No sound deadner 11. 305 with a tpi and 700r4 2.73 gear or 3.08 12. No dumbo mirrors 13. Shortbeds are better on gas 14. Low rolling resistance tires 15. Sport rear bumper is lighter than a step bumper. Roll pan is better still. Including front roll pan 16. Aluminum engine components like water pump, heads, intake, and a mini starter all kill weight in a big way These are things that are attainable by the majority of all square owners You can go with a new Lsx swap and make more power with as much fuel being burned Posted via Mobile Device
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377 sbc thumpr cam autogear m23 muncie 3:73 Detroit trutrac 3''spintech prostreet mufflers xpipe 1 3/4 headers build thread !http://67-72chevytrucks.com/vboard/s...d.php?t=577217 Iroc gauge threadhttp://67-72chevytrucks.com/vboard/s...d.php?t=554511 Last edited by INSIDIOUS '86; 03-30-2012 at 10:02 PM. |
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#45 |
Registered User
Join Date: Aug 2009
Location: hillborough nc
Posts: 410
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Re: Dont take this as ignorance but as gaining knowledge
http://usbodysource.com/
this place has complete fiberglass bodys for 73-87 chevys they also sell beds, fenders, cabs and everthing else... you just are going to need money as long as train smoke and alot of time to get everything to fit right but that would realy cut down on your weight
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77 chevy BIG 10 350/sm465/12bolt w 3.73 bout 240 horse power NO power steerin 79 chevy 1/2 ton 250/three on the tree/3.08s soon to get built 250/floor shift conversion/3.08s 81 mercedes 300d 25 MPG 77 chevy BIG DOOLEY 454/sm-465/14 bolt 4.10s "fully loaded" 73 plymouth duster 225 slant six/230 3 speed/8 1/4 trying to acheve 300 horse six http://www.cardomain.com/ride/3135091 '77 chevy trucks. built to stay tough. life is short build a hot rod ![]() |
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