Gas mileage difference between 4.3 v6 and 5.7 v8

Discussion in 'Chevy C/K Truck Forum' started by bigburb, Sep 23, 2009.

  1. bigburb

    bigburb Rockstar ROTM Winner 100 Posts

    Hey guys, I'm looking at this 1990 Chevy truck with the 4.3 v6 and a 5-speed. I was just wondering, is the gas mileage difference enough to make up for the less power it has? I want a v8, but if the difference is good enough I might just get the v6.

    Your thoughts on this?

    Oh, and here's the truck I'm looking at if anyone was wondering:
  2. jmckee6

    jmckee6 Rockstar

    I have a '99 old body style 1/2 ton with the 5.7 V8 and I usually get 15 or 16 in town and about 18 on the highway. That is with moderate driving, if i go easy around town I can get 17 or 18, and I get 18 on the highway with going 75, as long as its not uphill in the mountains. The only addition to it I have is a high flow K & N air filter, everything else is stock. I'd go with the V8. There are tons of add ons to improve gas mileage, I plan to buy some of them, but I haven't had the time or money yet to play with it much.
  3. vncj96

    vncj96 Epic Member 5+ Years 1000 Posts

    First, $2500 for a 20 year old 4x4 is a little high priced, but being a five speed, you should be able to get in the 22 range, my buddy on his 98 4.3, it has also been my experiance that the old TBI motors are easy to extract better mileage then the Vortec motors. Being that its a five speed you can control the engine so much easier by having it in a higher gear, or starting out in 2nd gear from a stop to cut the RPM range, I did this all the time in my old sonoma and got an easy combined MPG of 28 out of the 2.8 V6, I also had dual exhaust with two glasspacks and it sounded awesome.
  4. bigburb

    bigburb Rockstar ROTM Winner 100 Posts

    Hmmm... well what the difference between the two motors power wise?
  5. vncj96

    vncj96 Epic Member 5+ Years 1000 Posts

    For that year the motors are non vortec and are TBI so the ratings are not high to begin with, I think the 350 is in the 200hp and the 4.3 is at 150hp, dont quote me but I am sure this is very close, as I believe the last TBI 350 was in 1995 and was around 220hp. It will be noticable, but for me, I would buy for the MPG as like you I already own a suburban
  6. bigburb

    bigburb Rockstar ROTM Winner 100 Posts

    Yeah, my 'burb is killing me. I drive 9 miles each way to school twice a day on monday/wednesday/friday and once a day on tuesday/thursdays. Plus work on weekends, but if I'm getting a new job soon I will be driving to a job more often. My friend had a little s-10 with the 4.3 v6 and it gets up pretty quick, but it's also the Vortec.
  7. Custom04Chevy

    Custom04Chevy Rockstar 100 Posts

    I don't know about 20 years ago, but I know that my 4.8L gets the same mileage as the 4.3L that a buddy of mine bought. His is an 02 and he has 4x4, mine is an 04 and I don't have 4x4. Don't know if that helps you at all.
  8. Weak66

    Weak66 New Member

    I had a 4.3 in a 1986 S-15. Used it on a farm. Wasn't nothing it wouldn't pull. Hopper wagons, water tanks, tractors that got in the mud a little deep. I'm looking for another one. Was in an accident. Absolutely love that motor.

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