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better gas mileage

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BIGDAN112686, Nov 30, 2003.

  1. BIGDAN112686

    BIGDAN112686 1/2 ton status

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    alright everyone, i know gas mileage isnt expected out of a 1990 blazer with a 350, but i know it can be improved. lets say everyone had 500 dollars to spend on their truck, mostly to improve gas mileage. i wanna hear some suggestions on what would happen. thanks in advance.
     
  2. Thunder

    Thunder 3/4 ton status

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    I have an 89 K5 I get 18 MPG at 75 on the freeway no problem
    I Can get 16 towing my boat under good conditions. Best ever did was 20 following a buddys motor home doing 60 mph.
    If I keep my foot out of it around town I get 12 mpg and about the same off road.
    I built my rig to get gas milage I dont care about performance. (Although it will peg the spedo no problem and get there pretty fast}
    here,s my mods:
    Edelbrock TES headers
    3" single exhaust/Flowmaster 70 series Muff(No Cat)
    Performance Distributous dyna module/coil
    Taylor spyro pro wires
    The following TB mods from http://www.turbocity.com
    Injector spacer
    1/2" TB spacer
    Velocity stack (replaces the spacer between the air cleaner and the TB
    Adjustable fuel pressure regulator
    Flow matched injectors.
    Electronic Adjustable MAP sensor.
    That will easly blow your 500 bucks.
    If you want to save a big chunk of dough and only care about mileage. Dont get headers. They really dont do a thing for gas mileage. Just build a good flowing single 3" exhaust system.

    My Blazer:
    [​IMG]
    89 K5 350, 700r4, 3.73 gears, locked, 33" MT tires. synthetic lubes in drive train.
     
  3. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Buy a $500 Honda...that'll improve your mileage dramatically.

    Rene
     
  4. BIGDAN112686

    BIGDAN112686 1/2 ton status

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    thanks alot for all the ideas. ive been lookin around, doin some searches. jus gotta decide where to start i guess. and as for the 500 dollar honda, im 17, cant afford insurance on 2 cars and no way my parents would let me keep 2 cars in the driveway.
     
  5. SUBFAN

    SUBFAN 1/2 ton status

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    Keep the air pressure in the tires correct. Driving style is the biggest factor....Pretend as if there is an egg under your right foot.

    Installing a vacuum gauge and driving for the consistently highest reading will help too....
     
  6. Blue85

    Blue85 Troll Premium Member

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    That's what I do. Although I often find that I desire the sound of headers into dual exhaust at 3500 rpm to a reasonable vacuum reading. I can get 15mpg on the highway, but the speed has to be kept down. At 50-55mph, it can go even higher. I need FI, though.

    There have been a lot of threads on this very topic in the past. The key is to make sure that you aren't spending more on mods in quest of high mpg than you would have spent on the extra gas.
     
  7. BIGDAN112686

    BIGDAN112686 1/2 ton status

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    ive been workin on the driving methods, and it seems to be workin. that, and my random drivin around has stopped a whole lot. i think i might just stick to drivin smarter for a while and see how it goes.
     
  8. SUBFAN

    SUBFAN 1/2 ton status

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    No matter what you do, you will never get good mileage on all those short hops to the gas station..... /forums/images/graemlins/thumb.gif
     
  9. TopOff

    TopOff 1/2 ton status

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    [ QUOTE ]
    alright everyone, i know gas mileage isnt expected out of a 1990 blazer with a 350, but i know it can be improved. lets say everyone had 500 dollars to spend on their truck, mostly to improve gas mileage. i wanna hear some suggestions on what would happen. thanks in advance.

    [/ QUOTE ]

    Keep a light foot,

    Keep your highway speed consistent and as slow as possible without needing to downshift.

    Keep it in tune.

    Overfill the tires, or get stock size tires.

    /forums/images/graemlins/thumb.gif
     
  10. BIGDAN112686

    BIGDAN112686 1/2 ton status

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    since ive been takin it easy on it, ive been gettin much better mileage. for now, this is the way to go for me. thanks for the opinions and suggestions.
     
  11. conoverbandit

    conoverbandit 1/2 ton status

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    Don't laugh, but I was apporched by a fella some time ago trying to sell me this "miracle" gas saver.......after looking at it and figuring out what it was really behind the fancy packaging, I told him I was'nt interested (at 200.00 a pop) so one day I thought about what he was trying to get me to buy and I found a busted set of speakers on my trash route, I took the magnets off and clamped them on my fuel line..............I can tell when the electrical tape comes loose and they fall off, My 71 gmc is a real fuel eater.This truck was designed when fuel saving was'nt a real issue, so to say that it "burp's" when I pass a gas station is an understatement. But any how I put the magnets on my fuel line, and It works, not sure of a MPG increase but I can tell when they fall off. This does something to the hydrocarbon's in the fuel, supposed to burn cleaner with a little more power and economy.It's supposed to work on gas,diesel, ect. I have magnets on almost every vehicle I own, and I say almost because I have'nt found any busted speakers lately. but try it and see.
     
  12. 84_Chevy_K10

    84_Chevy_K10 Banned

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    That is one of the biggest scams of all time (the magnet thing)
     
  13. supersize75

    supersize75 1/2 ton status

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    I am a trottle junkie, just installed a big block too, I enjoy driving my truck alot, maby when I am older I will think more about gas, but for now I'm chirpin the 38's and giving the motor hell /forums/images/graemlins/thumb.gif


    love life /forums/images/graemlins/thumb.gif /forums/images/graemlins/k5.gif
     
  14. tecton

    tecton 1/2 ton status

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    [ QUOTE ]
    I am a trottle junkie, just installed a big block too, I enjoy driving my truck alot, maby when I am older I will think more about gas, but for now I'm chirpin the 38's and giving the motor hell /forums/images/graemlins/thumb.gif


    love life /forums/images/graemlins/thumb.gif /forums/images/graemlins/k5.gif

    [/ QUOTE ]

    amen
     
  15. 91GMCSuburban

    91GMCSuburban 1/2 ton status

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    it's minute, but reduce friction (and life), use sythetic fluids in engine, tranny and axles.
     
  16. pauly383

    pauly383 Daddy383 Staff Member Moderator

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    Don't forget to change your air cleaner more often than you think, either spend for a cleanable one or just spend 5 dollars a month on fram. More clean air in equals more effiency.
     
  17. GM Man

    GM Man 1/2 ton status

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    I bought a $500 honda and it left on the side of the road with a blown motor. /forums/images/graemlins/angryfire.gif And this was owned by an old man who took care of it. No more hondas for me.
     
  18. Thunder

    Thunder 3/4 ton status

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    Here are my sugustions for spending 500 $ to get better milage.

    1. Good exhaust should be your first purchase.
    Single 3" (like stock) with a good lowback pressure muff and a high flow cat. The stock Cat is pretty restrictive and plug up as they get older.3"
    Flowmaster 50 or 70 series muffs are good or for less money Check out a 3" Summit or dynomax muff.

    2.MSD blaster 2 coil(for 87 &up GM). These will bolt in and plug into your wireing harness like stock. The hotter spark will allow you to open up the spark plug gap to .050-.060" that will help milage a little.

    3.Go to http://www.turbocity.com(their website is down right now but should be up soon Ph# 714 639 4933)
    They have a TBI performance page. Get the Air flow enhancer and throttle body spacer spacer. These improve throttle response and boost air velocity at low speeds They will help with around town and highway gas milage. If you install a TB spacer you may need to re- adjust the TV cable. raising the TB more than 1/2 inch will throw it out of wack.

    3.Air filter: K&N. or for paper go with AC delco. Stay away from Fram or Wix they are the worst flowing filters on the market.

    4.Keep your tires aired up and check regurlarly. Do not excede max pressure. properly aired tires reduce rolling risistence= better gas milage.

    5.Change all the fluids...Engine, tranny, Xfercase, and diffs, and keep them clean and changed regularly use synthetics if you can afford them.

    6.Use at least 87 octaine gas. TBI doesn't like less than 87. 89 octaine is the best. Also a can of injector cleaner once a month or two is a good idea.

    Tune it up!!!! Ac Delco plugs, 8mm plug wires, AC delco or aftermarket performance Cap and rotor. Check all vacume lines and throttle body gasket for vacume leaks.

    Doing these sugustions and proper driving will increase the fuel milage significantly. you will also get a nice boost in performance.
    One of the reasons I like my K5 is it gets better fuel milage than any fullsize 4x4 I have ever owned.
     
  19. TopOff

    TopOff 1/2 ton status

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    Thunder is right!

    According to "Performance Ignition Systems" by HP books
    IDSN 1-55788-306-8

    Tune your vehicle often gapping your plugs (+) wider gap, (-) smaller gap over manufacturer's recommendation:

    (+) .006 = 4% improved gasoline mileage noticeably smoother opreating, no change in power.

    (-) .004 = 5000 more miles between tuneups. 2% full throttle pwoer, lose 3-5% mileage

    dirve it lightly (+) .010 6% improvement in mileage 2% improvement in power.

    Achieve maximum power (-) .010 6% improvement in power, more fouled plugs, 7% loss in mileage, more often will need a tune-up.


    Add a computer ignition system (+).025 gap = Increase power 8-12%, increase milage 11-23%.

    This was taken from Four Wheeler magazine.
     
  20. bnc04

    bnc04 Guest

    Thunder, in one of you other posts you recommended a screamin deamon coil? Have you changed thoughts for some reason? I have some of your earlier posts printed out as your model is one I am going to follow.

    I currently have a stock 88 with a 350 TBI with 32.5 inch tires and 3:42 gears.

    I so far have added a high flow cat and 3 inch exhaust with a 50 series muffler and changed 02 sensor. I already have a K&N filter, I flipped the air cleaner lid and removed the front baffle at the grill for better air flow. I can really feel the improved throttle response and mileage is now at 12 ( up from a soft footed 10) in some pretty aggressive city driving. (One tank through it so far)

    I plan on following your ignition advice and also purchasing the turbo city suggestions so if you did change your thoughts, please let me know.

    Thanks
    Brett
     

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