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Gas mileage

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by KILLERK5, Dec 24, 2000.

  1. KILLERK5

    KILLERK5 1/2 ton status

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    What kind of gas mileage do you guys get? I figured mine out, i'm only getting 9 miles to the gallon! Is there any way to improve it? I'm willing to do about anything. (reasonable atleast) Please let me know.

    Thanks & MERRY CHRISTMAS
     
  2. 90K5

    90K5 1/2 ton status

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    I get about 9-11 depending on how I drive it.

    90K5

    See my truck at <A target="_blank" HREF=http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502>http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502</A>
     
  3. loudandproud

    loudandproud 1/2 ton status

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    Location:
    Ham Lake, Minnesota
    8.5 with one of mine and around 14 with the other.

    DOOH!![​IMG]<A target="_blank" HREF=http://loudandproud.coloradok5.com>http://loudandproud.coloradok5.com</A>
     
  4. gokartergo

    gokartergo 3/4 ton status Staff Member Moderator

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    Hollister, CA
    I have a brand new crate 350 in my 86 with less then 1000 miles on it. I have been has high has 11.8 and has low has 10.4. Not much more I can do other then replace the stock air filter with a K&N filter. That is supposed to increase it about 1 mpg. Also keep the tire pressure up.

    Gokartergo
     
  5. fknfbm53559

    fknfbm53559 Registered Member

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    Location:
    quitman texas
    im getting about 7.4 highway use, havent found anyway to really increase it but im thinking in investing in one of those tornado things that fits inside your air filter, jc whitney offers them for pretty cheap, its supposed too increase mileage by 2-5 mpg and 14% horsepower

    washing a k5 is never done somehow i keep finding those 3 foot deep mud pits on the way home
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

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    How about more specs on the truck? With my '83, at over 130,000 miles, I was getting 17mpg freeway, 10-13 city. Specs of the truck were original 305, liked to smoke, rebuilt Q-jet, TH700R4, 208, 3.08's, 31" tires. Up until I changed the plugs, wires, and oil after I bought it, I know it was much, much worse.
    depending on transmission, motor, gears, condition of carb, and tires, your mileage may vary : )
    Personally I'm expecting about the same mileage out of my '86 when I get it completed.
    http://yeagerd.home.mindspring.com/index2.html
     
  7. chevy4x4

    chevy4x4 1/2 ton status

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    Here is what I'm going to do to get better gas mileage:

    Take top off and sell it.
    Put on a soft top.
    Remove all the seats.
    Make or buy one light racing seat.(for the driver only)
    Take out all the carpets.
    Take out the radio.
    Replace gas tank with smaller one or fuel cell(maybe)
    Remove spare tire.
    Remove doors(summer)
    Put in a huge exhast pipe with low restriction muffler(s)
    Put in a huge are intake system(need it for diesel)
    Replace tail gate with one from a pick up(not sure if it bolts up)
    Replace some body pannels with fiberglass(if I have enough money)

    Thats about all i can think of now.


    [​IMG]
    [​IMG]K5[​IMG]
     
  8. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    E-town baby!
    Hey man if you really want good mileage out of your K5, lower it, run small light tires, front air dam, lose the trucker mirrors and windsheild wipers, and keep the hard top. Deisel is good or a straight six, then gear it so it runs in its most efficient RPM range on the freeway. Keep it well tuned, and drive it gently.[​IMG][​IMG]
    Of course everything I've done to my truck is the exact opposite of that and thats what makes me love it!!!!!!![​IMG][​IMG] Well except for keeping it well tuned.
    K5's are never gonna get astounding gas mileage. Especially the way we like them built![​IMG]
    A standard transmission does help a little, so does gearing and engine tune. Aerodynamics are the enemy though. Lets face it a K5 has the aerodynamic qualities of a barn! I found that my highway mileage increased from under 10 MPG (US gallon) to 14+ MPG just by staying at or near the speed limit.[​IMG] The side benefit was getting to work a little more relaxed than trying to set a new speed record every day![​IMG]
    My Jimmy has a mild 350, Flowmasters, 3.73's, 35" MT's and a SM 465 4 speed. My best mileage is at about 60 MPH steady cruise, 2150 RPM (approx.)

    Rene

    [​IMG]
     
  9. MudFrog

    MudFrog 1/2 ton status

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    I get around 13 in town, depending on how I drive. Although it's really hard for me to keep off the pedal.

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  10. Cavalry

    Cavalry 1/2 ton status

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    Location:
    upstate NY(although I cant figure out why)
    I went on a 7000 mile trip last summer.....averaged 21MPG....with 350HO, 700R, 308 gears, 31"tires, haulin ass all the way. If I'm horsing on it around town I only get about 13MPG
     
  11. Hayduke

    Hayduke 1/2 ton status

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    Location:
    NE Columbus, Ohio
    i get a solid 12.5 mpg with my 305. it has 106k and smokes a bit too. after i do a complete all-around tune up here soon i'm wondering if it'll get better.......still it's totally worth it having a K5!!

    Insured By COLT, Policy #.357M

    <A target="_blank" HREF=http://haydukesk5.coloradok5.com>http://haydukesk5.coloradok5.com</A>
     
  12. Cmoe

    Cmoe 1/2 ton status

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    9 to 10 fpg(feet per gallon) up hill or down. Just feels like it at times. I've tried just about every thing to get better. Next is a FI system & 2.25 dual exhaust. I'm running 35's" with 4.56 gears (removed front drive shaft), Built 350,rebuilt 350 turbo, 205 T-case, true dual exhaust from factory (without cats due to being a '78 that came from the factory without them).

    C'moe

    <font color=black>the blazer is "Back in Black"
     
  13. Chris Demartini

    Chris Demartini 1/2 ton status

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    Location:
    Dumont NJ 07628
    <font color=blue>I'm too afraid to check for sure (plus my speedometer and odometer still arent corect) but from some longer drives I've taken, Im guessing around 9 on the highway and 7-8 around town. I have a mild 355, edlebrock carb and intake, headers, dual 2 1/4" exhaust with 2 chamber flowmasters, SM465, 4.10s and 36" TSLs. I found that the soft top takes away about 1-2 MPG and no top at all takes away another mile or two. Mileage doesnt concern me because my truck isnt my daily driver, but I want to get an 87-91 K5 to keep stock as a daily driver (the car just aint no fun! [​IMG] ). What kind of mileage do you guys with TBI 350s/700R4s and stock tires get?</font color=blue>

    [​IMG]
     
  14. rezalb

    rezalb 1/2 ton status

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    Location:
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    GAS MILEAGE....Who drives a K5 for gas mileage??????
    Get a moped for optimal gas mileage.......I drive my K5 for safety, wheelin, hunting and fishing, and on and on and on..Accept the trade off of poor gas mileage for the huge list of other MORE important reason you may have.....but it is pleasing to know other fellow K5 pay the same tab I do.

    rezalB

    Built for a purpose.
     
  15. HarryH3

    HarryH3 1 ton status Author

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    First make sure that your speedometer is correct. If you've added bigger tires without re-gearing the diffs and/or correcting the speedo drive, you may be travelling a lot further on a tank of gas than you think you are.

    With a TPI 383, Turbo 400, 4.10's and 35's my '75 gets 13.5 mpg on the highway. In town and wheeling I might as well just measure in gallons per hour, like they do with boats! [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
     
  16. kumma

    kumma 1/2 ton status

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    87 jimmy 350 TBI 700 tranny and 3.08 gears i get around 12-14 miles per gallon. my speedo is off due to 31 inch tires so you have to figure maybe an extra 10% on top of those numbers. these figures are for 50/50 city highway miles. - to improve your milage, tune up, tire pressure higher, but even with that it may only be 1 or 2 miles, just enjoy the K-5 and leave the mileage worries to the imports.
    Craig
     
  17. Thunder

    Thunder 3/4 ton status

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    I get 18 mpg on the freeway at 65. The best I ever did was 20 following a firend who was driving his motor home at 55 mph. I have a 89 with tbi, 700r4, 373, gears and 32" tall tires.One of the reasons I bought my TBI K5 with overdrive, was the good gas mileage(for a 4x4) they get. I had a carburated Blazer and the best I could get was 12 mpg at 55 with a good tail wind.
    Adding fuel injection will improve the gas milage. But it is expensive Unless you can get The complete system out of a wercked truck for cheap. A buddy of mine put a Holley Pro injection system and a flowmaster exaust on his Suburban and he said he picked up about 5 mpg and it runs a whole lot better.
     
  18. chevy4x4

    chevy4x4 1/2 ton status

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    Biggray, shouldn't taking your top off give you better milleage rather than make it worse?

    [​IMG]
    [​IMG]K5[​IMG]
     
  19. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Worse aerodynamically=more drag=worse mileage
    Same goes for open windows, big ass mirrors, soft tops, tall trucks etc.
    The smoother and lower the truck the less drag.

    Rene

    [​IMG]
     
  20. chevy4x4

    chevy4x4 1/2 ton status

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    Beeing aerodynamic is mostly important when traveling high speeds right? If city driving is all what the blazer does would it be better to have a hardtop, no top, or a soft top that stretches from the cab to the tailgate fot the best mileage. I hear it lots of times that people say they get better mileage without the top due the reduction of weight.

    [​IMG]
    [​IMG]K5[​IMG]
     

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