Whats you gas mileage on your squarebody truck?

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mibars

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Location
Nadarzyn, Poland
First Name
Michal
Truck Year
1990
Truck Model
Suburban V1500
Engine Size
350 TBI
Next refueling and I got more "typical" gas mileage for a Suburban: 19.7 l/100 km or 12 mpg
That's with mixed city/highway driving, traffic jams and me more comfortable with flooring that beast.

Fun fact: Clerk was double and triple checking if I do realize that I'm paying for gasoline and not diesel as it is uncommon in Poland to have a large vehicle with large tank that does not run on diesel :)
 

Redfish

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Location
Prairieville, LA
First Name
Andrew
Truck Year
1987
Truck Model
V1500
Engine Size
350/5.7
I actually have been thinking about this and redfishs comments on the diesel mpg. Especially since I drove it home from Columbia,MO. To Linn County Kansas. Filled up in Columbia,drove to Lee's Summit then home. Figured the milage 25mpg. 6.2 4l80e. Did the math again,told a buddy said I can't believe this he ran the numbers said yea that's it. But thinking this over real hard odometer,and 2 different gas pumps. In reality I don't know exactly how much I burned just how much it took to top off. Milage IDK what ever the ODO says. So now I have no idea,and I hate you guys. Thanks
You are Very Welcome!

I had a roughly 3 hour back road drive to and from Cruisin the Coast with The '87 very heavily loaded. I even had Mrs. Redfish/BigUn riding shotgun... According to the odometer which is now incorrect because I have 33 inch mud grips, I am getting 14ish mpg. That probably works out to about 15 mpg which is better than I deserve.

By contrast my 2019 2500HD Duramax 4wd would have averaged about 19 or 20. It does better than that but then goes into a Regen on Every Single Tank of diesel which kills the fuel mileage. I HATE that.

My Pop drives a wonderful GMC AT4 with the 6.2 and 10 speed auto. He just made a round trip from Port Vincent, Lousiana to Philadelphia, Tennessee and back. He averaged an honest 20.9mpg.

Regarding your Hate...You know that Hate is a very powerful emotion. You have to be emotionally invested to truly feel Hatred. This means that you care about @Grit dog and myself. I personally appreciate that and I am sure Grit Dog does as well. :cool:
 

sidschev

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Location
Arkansas
First Name
sidney
Truck Year
1984
Truck Model
c1500
Engine Size
350
man y'all get good milage... i get about 4 mpg maybe 5..... but my enging is shot and the carb who knows if its adjusted or not. i can drive 30 miles and burn half tank to 3/4 tank of gas and 2 quarts oil :D:Big Laugh:
 

84GMCSierra

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Location
Central Arizona
First Name
Paul
Truck Year
1984
Truck Model
C2500
Engine Size
350
I get about 8! I replaced the vacuum lines, has a new distributor, carb in 2019, and getting new plugs and wires. Runs smooth at idle, but under a load, it feels like it's missing. Sending it in to the shop in a couple weeks to have it all checked out
 

SquareRoot

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Location
Arizona
First Name
Mike
Truck Year
85
Truck Model
K20
Engine Size
350
15mpg. I offset that by driving my 2,8 Duramax AT4 half the time. It gets 30 mpg. I'm about to buy a new Kawasaki KLR 650 to ride to work a few days a week. It's advertised to get 41 mpg. Let the good times roll. :laughing1:
 

Redfish

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Location
Prairieville, LA
First Name
Andrew
Truck Year
1987
Truck Model
V1500
Engine Size
350/5.7
15mpg. I offset that by driving my 2,8 Duramax AT4 half the time. It gets 30 mpg. I'm about to buy a new Kawasaki KLR 650 to ride to work a few days a week. It's advertised to get 41 mpg. Let the good times roll. :laughing1:
A brand new KLR? I kind of hope it gets better than 41mpg. My DR 650 gets anywhere from 46 to 51 on paved roads. Somewhat less off-road depending on all of the obvious factors.
 

SquareRoot

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Arizona
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Mike
Truck Year
85
Truck Model
K20
Engine Size
350
A brand new KLR? I kind of hope it gets better than 41mpg. My DR 650 gets anywhere from 46 to 51 on paved roads. Somewhat less off-road depending on all of the obvious factors.
That's from a quick Google search. Can't seem to find official Kawasaki numbers. Actually I don't think I care cause the fun factor outweighs any thought of gas milage. Lol. Right now it's just a good argument point to convince my wife I need this bike.
 

SirRobyn0

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Location
In the woods in Western Washington
First Name
Rob
Truck Year
1984
Truck Model
C20
Engine Size
305
I was having a conversation with one of the new guys at the shop about this. Our old trucks can get a really wide range of gas mileage depending on it's configuration. My dad when he had his 78' K20 stock 350 SM465 4.10 he pretty much got 10MPG whether he was communing to on a highway trip. My 84' C20 305 700R4 3.41 I get about 12 on my commute, and I've touched 16 on the highway if driven around 60 with a light foot, but she'll get in the mid- 15's going 70. When I consider that my 92' Dakota 3.9 magnum V6 2WD truck did 11 on my commute and 16 on the highway I feel like my square is not to bad on gas. But of course it's less than a modern truck....
 

TotalyHucked

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Location
Auburn, Georgia
First Name
Zach
Truck Year
1985
Truck Model
Sierra 1500
Engine Size
5.3
Well, I've run about 4 tanks through my new setup. Didn't calculate the first but so far I've gotten 19mpg on the hwy with some stop and go, 13mpg horsing around on backroads and 22mpg on the way home. Bigger cam, bigger injectors but more overdrive (.63 in the T56 vs .69 in the 4L65).
 

Bextreme04

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Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
After getting an AFR meter on the truck and dialing in the Carb I'm getting about 10-12 depending on how much I'm beating on it. That's 35x12.5" tires, 4" lift, and 350/TH400/NP205 with 4.10 gears. The engine has a small summit 1102 cam, ~9:1 static compression and stock 882 heads.
 

mibars

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May 13, 2023
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Location
Nadarzyn, Poland
First Name
Michal
Truck Year
1990
Truck Model
Suburban V1500
Engine Size
350 TBI
Once again I hit 17 MPG (13.9 L/100 km) on a trip, not that terrible for the size of that thing. Mostly rural highways, some expressways, some country roads, even some dirt and cobblesone roads because why not in a 4x4 Burb :)
 

Eric leadfoot

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Location
Santa rosa ca.
First Name
Eric
Truck Year
1974
Truck Model
C10
Engine Size
460ci
Ya...my 74 stepside with a 500 hp big block 454 (+.0030) with a muncie m20 and 3.08 gears averages about 8-10 depending on length of freeway driving and throttle position....around town about 7-8. Again depending on throttle position....got a 750 cfm holley double pumper with milled choke plate....I didn't build it for the gas milage....
 

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