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#1 |
Registered User
Join Date: Apr 2010
Location: Ardmore, OK
Posts: 164
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'84 K10 getting 8.9mpg....is this normal?
I have been curious for a while on what the MGP were on my 84 SWB K10. I was thinking that it couldnt be very high because it seems like it sucks the gas pretty quickly. This truck is all stock, 350, 700R4, no lift, 31" tires. It has a recent rebuild on both motor and trans (within 10,000 miles). It has stock manifolds, Magnaflows, and NO cats.
I checked the MPG on it over the past week and it came out to 8.9MPG with a combo of town/Hwy driving in on average 95-105 degree heat with the A/C on MAX the entire time. Is this about average compared to everyone else? It seems a little low, even for a 4wd and running the A/C. Any adivce to on helping to increase this besides the usual tune up stuff like plugs, wires, cap, etc.... The truck runs great, nice and smooth, no issues at all.
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1984 K10 SWB "Coal" 1987 K5 Blazer "Ole Miss" 1979 GMC Jimmy (Project) 2008 F250 CC 4x4 King Ranch 6" lift on 37's (Spartan-ized!!) 2008 Dodge Challenger SRT8 Hemi Orange 2008 HD StreetGlide 2007 HD Custom Fatboy 1980 Suburban (will be for sale or trade soon). |
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#2 |
Registered User
Join Date: Dec 2006
Location: SLC, UT
Posts: 706
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Re: '84 K10 getting 8.9mpg....is this normal?
It will be interesting to see what others have to say. Your milage doesn't seem too far out of line to me considering you have been running the air constantly.
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#3 |
Registered User
Join Date: Jun 2011
Location: Downey, ca
Posts: 262
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Re: '84 K10 getting 8.9mpg....is this normal?
Seems too low to me...especially with a 700R. Could be your gearing and the 31'.
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#4 |
Registered User
Join Date: Jun 2010
Location: Holly Ridge NC
Posts: 11
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Re: '84 K10 getting 8.9mpg....is this normal?
I get the same in my truck, Ive got 6" of lift and 35" tires though...
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If its stupid but it works, its not stupid ![]() 1983 K10- GM performance 350 Edelbrock Air Gap Intake, 650 Carb & Adapter Plate. Rebuilt 700R4 with Corvette Servos. 6" suspension lift 35" Maxxis Buckshot Mud Terrains. Need to install- Vortex 12000LB winch, Tactical Armor Group wincher front bumper, high lift jack mounts, resse hitch Wants- Axles off a one ton, Rhino line the whole truck, More power and a magic fairy to fill my gas tank |
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#5 |
Registered User
Join Date: Dec 2009
Location: Epping, NH
Posts: 605
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Re: '84 K10 getting 8.9mpg....is this normal?
I get the same with my truck, and I've got a th400 3 speed, cast iron t-case, 6 wheels, 4 doors and 4.10 gears. Oh yeah, I've got a 454 with a 4 bbl too. I would expect to see 12-14 with your combo, depending on gear ratio. You likely had 3.08s with that motor/tranny, but not for certain.
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1982 Chevy K30 CCLB fleetside. Formerly a cab and chassis, now a fleetside dually with the rear wheels tucked underneath. 454/th400/np205/C14/D60, 6/4 inch LIFT, not drop. |
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#6 |
Registered User
Join Date: Apr 2010
Location: Ardmore, OK
Posts: 164
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Re: '84 K10 getting 8.9mpg....is this normal?
Hmm,
Well I guess it is low then. I was wanting to know what others were getting. I'm not positve what gears I have, I assume the stock setup. I suppose I need to check my plugs, wires, etc.... Posted via Mobile Device
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1984 K10 SWB "Coal" 1987 K5 Blazer "Ole Miss" 1979 GMC Jimmy (Project) 2008 F250 CC 4x4 King Ranch 6" lift on 37's (Spartan-ized!!) 2008 Dodge Challenger SRT8 Hemi Orange 2008 HD StreetGlide 2007 HD Custom Fatboy 1980 Suburban (will be for sale or trade soon). |
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#7 |
Registered User
Join Date: Aug 2009
Location: S.C.
Posts: 1,593
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Re: '84 K10 getting 8.9mpg....is this normal?
Depends on gearing, driving habits, condition of tune...
Full time 4wd? Turn off the ac and check it. If nothing else, I'd be curious. My father was happy if he could get 10 out of his '84 (and this was just a couple years ago.)
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'86 C-30 dually, 454/tbh400 '73 K-20 350/350/205 (sold ![]() I'm kinda like duct tape- no real purpose, but handy to have around. |
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#8 |
Registered User
![]() Join Date: Apr 2009
Location: Kennewick WA.
Posts: 1,437
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Re: '84 K10 getting 8.9mpg....is this normal?
Ill take that anyday with my 454 powered dually
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#9 |
Registered User
Join Date: Jul 2009
Location: West Jefferson, OH
Posts: 999
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Re: '84 K10 getting 8.9mpg....is this normal?
That's low. When my '88 Burb was still stock, 1/2 ton, 350, 700r4, and 31's... it averaged 12-13. Now that it's lifted, bigger axles, etc, it still averages about 11mpg. Heck, I have to REALLY work my 454 Burb to get less than 9mpg.
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-Andy '77 K5 Blazer '78 K10 Shortbed '78 C20 Suburban '79 K30 Crew Cab Dually '84 C10 Short Stepside '88 K20 Suburban ![]() |
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#10 |
Registered User
Join Date: Jun 2010
Location: Holly Ridge NC
Posts: 11
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Re: '84 K10 getting 8.9mpg....is this normal?
What type of Axles/Gears are you running? I would love to squeeze even 2 more MPG out mine.
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If its stupid but it works, its not stupid ![]() 1983 K10- GM performance 350 Edelbrock Air Gap Intake, 650 Carb & Adapter Plate. Rebuilt 700R4 with Corvette Servos. 6" suspension lift 35" Maxxis Buckshot Mud Terrains. Need to install- Vortex 12000LB winch, Tactical Armor Group wincher front bumper, high lift jack mounts, resse hitch Wants- Axles off a one ton, Rhino line the whole truck, More power and a magic fairy to fill my gas tank |
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#11 |
Registered User
Join Date: Jul 2007
Location: Tucson, AZ
Posts: 3,188
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Re: '84 K10 getting 8.9mpg....is this normal?
This topic comes up often here. My experience after owning 3 old squares - expect no more than 9-10 mpg regardless on a big old heavy truck. If you have a 1/2 ton, overdrive trans, low number rear end, all stock, light foot on the accelerator, fuel injection (like an 87), small block or V6, you can get 14 city/18 highway or slightly better. 14/18 mpg is what the new GM full size pickups get, and they are designed for fuel efficiency. My 2010 GMC Sierra ext cab 4.8L, 4speed auto trans, 3.08 rear axle got 15.5 city/ 18.5 highway with very careful driving - so I would say that is the maximum achievable on a V8 pickup. I did have a V6 2000 Silverado that got 19 city/23 highway, but you won't be pulling any heavy loads with a truck like that. Others will post here with much better gas mileage numbers - but I never got that, although all of my squares were 3/4 ton trucks, which means I carry an extra 1000 lbs. of dead weight.
Some common tips an gas mileage: All tune up parts in good shape or replace - spark plugs, wires, cap , air cleaner Very light touch on the accelerator when leaving a traffic light Let off the gas when you are approaching a red light and coast to a stop Pump up air in tires to max inflation or near it (watch your tires wear sooner) |
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#12 |
Registered User
Join Date: Jul 2007
Location: Tucson, AZ
Posts: 3,188
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Re: '84 K10 getting 8.9mpg....is this normal?
One more thought - make sure you don't have a fuel leak. I had a leak at the fuel inlet nut on the carburetor which I never noticed because the gas would evaporate as soon as it leaked on the intake manifold so I never saw it - just smelled it - so I did not see it until it got very bad. Also, I just noticed a leak at the fuel pump - looks like it was leaking for quite a while but since the fuel dripped off directly to the ground because of the part location I never noticed it- I would have noticed it if I was under the truck with the engine running, something I never do. Bottom line - if you notice any gas smell check the fuel system completely with the engine running, maybe have someone you trust rev the engine while your check it out. I also had fuel slosh out of a full tank of gas because the rubber hoses at the sending unit or to the hard lines were cracked or loose - you might see traces of fuel leaks on the tank or lines - stains on the hose or tank.
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#13 |
Account Suspended
Join Date: Dec 2008
Location: indisclosed
Posts: 1,515
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Re: '84 K10 getting 8.9mpg....is this normal?
How are you calculating mpg?
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#14 |
Registered User
Join Date: Nov 2010
Location: Houston, TX
Posts: 6
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Re: '84 K10 getting 8.9mpg....is this normal?
my '78 2WD 350 4Bbl/TH350 with 3.73 gears and 235/75/r15 tires would only get 13 on a really good day. average, with air running, was between 9 and 10. you have the 700r4, which should help, but yours is 4WD, which in my experience negates the benefit of the 700r4. And, overdrive will only help you out on the highway, it won't do much for you around town.
I noticed a jump of about 1 mpg with the edelbrock performer intake, but ymmv. |
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#15 |
Farm Truck
![]() Join Date: Aug 2006
Location: Jersey Village, Texas
Posts: 547
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Re: '84 K10 getting 8.9mpg....is this normal?
My 84 K5 gets about the same.
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1969 CST/10 1984 K5 Blazer 4x4 2016 Dodge Ram 2500 4x4 Mike Jersey Village, Tx |
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#16 |
Registered User
Join Date: Apr 2010
Location: Ardmore, OK
Posts: 164
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Re: '84 K10 getting 8.9mpg....is this normal?
Number of gallons used divided by the total miles driven.
__________________
1984 K10 SWB "Coal" 1987 K5 Blazer "Ole Miss" 1979 GMC Jimmy (Project) 2008 F250 CC 4x4 King Ranch 6" lift on 37's (Spartan-ized!!) 2008 Dodge Challenger SRT8 Hemi Orange 2008 HD StreetGlide 2007 HD Custom Fatboy 1980 Suburban (will be for sale or trade soon). |
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#17 |
Registered User
Join Date: May 2010
Location: laurel hill Fl
Posts: 645
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Re: '84 K10 getting 8.9mpg....is this normal?
do you live on a mountain/drag strip. that's ridiculously low.
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1985 C10 Custom Deluxe LWB 305/700r4 [ Goldfinger ] ![]() 1999 k3500 crew cab dually 6.5tdi/4l80e |
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#18 |
Registered User
Join Date: Nov 2008
Location: kannapolis, nc
Posts: 507
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Re: '84 K10 getting 8.9mpg....is this normal?
my 85 k10, 350, 700r4, carberated, on stock 31's gets 15. I can get better when tuned up. thats no a/c also
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#19 |
Registered User
Join Date: Oct 2009
Location: North Carolina
Posts: 151
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Re: '84 K10 getting 8.9mpg....is this normal?
Mine is getting about 8-9 mpg also but I know its not running right.
I have a timing light on the way and a new distributor. I put a new edelbrock 600 cfm carb on it, new fuel pump and new plugs and it made no difference on mpg but runs alot better. I will see this weekend if the new distributor and timing helps. Oh, mine is an 83 K10 short bed, standard gearing but I have a 4 speed manual with granny gear. I get that mileage at 65 mph with AC on. |
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#20 |
Registered User
Join Date: Jul 2010
Location: jacksonville nc
Posts: 1,229
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Re: '84 K10 getting 8.9mpg....is this normal?
i just drove my 84 from jacksonville nc to south of the boarder sc, and i was getting 10 to 11 on the high way and i get a little better when im in the city, kinda wierd...running 35's with a six inch lift
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#21 |
Registered User
Join Date: Dec 2010
Location: Pittsburgh, PA
Posts: 1,009
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Re: '84 K10 getting 8.9mpg....is this normal?
That's about what I get, but I have a K20 sitting on 38's with a TH400 and a mild 350. Yours should be better, for sure.
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Steve Member of the Foot Pedal Club '83 Chevy K20: 6" Rough Country, 3" Performance Accessories BL, Bushwacker Cutouts, 38x15.50 Mickey Thompson Baja Claws, 350 HP 350 crate engine from Jegs, Turbo 400 ![]() |
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#22 |
Registered User
Join Date: Mar 2007
Location: Austin, TX
Posts: 292
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Re: '84 K10 getting 8.9mpg....is this normal?
Everything Tusconjwt said sound advice. I think you can achieve better fuel efficiency, so start experimenting with some of these items. Check for leaks, tune or rebuild your carb, tune up you truck, set your timing properly, repair exhaust leaks, max out your tire psi, and manage your foot. You will see improvements.
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#23 |
resident wrencher
Join Date: Dec 2006
Location: ramona california
Posts: 720
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Re: '84 K10 getting 8.9mpg....is this normal?
Make sure you odometer is correct that will affect it mins off i thought i was getting 10 average i did some mapping of my routes and it turns out im gettin 15
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#24 | |
Registered User
Join Date: Mar 2007
Location: Austin, TX
Posts: 292
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Re: '84 K10 getting 8.9mpg....is this normal?
Quote:
My speedo doesn't work, my gas gauge doesn't work, non stock tire height, and my dash light are out. I run out of gas all the time. I had to get smart and this app helped me a lot. |
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#25 |
Registered User
Join Date: Jul 2010
Location: jacksonville nc
Posts: 1,229
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Re: '84 K10 getting 8.9mpg....is this normal?
oh i also forgot to mention that mine has a couple gas leaks and im getting that....gonna be fixing those leaks this weekend
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