Whats you gas mileage on your squarebody truck?

[HotRodPC]

I know it is a 48re. Not sure who made it and I have no idea what axles either. I wanted an auto because I already own a stick and didn't want two. If I turn up power the driveline will be a concern but it should hold up at stock levels. The dealership where I bought this truck actually let me take an 11 superduty to go get the house. I can't speak for reliability, but the power was BADASS! The gas mileage sucked but that thing hauled ass it got 14 on the highway and 12 pulling. My dodge gets 20 and 11 pulling, but that ford would have killed it in a quarter and probably top end too. No doubt.

Yes, the StupidDuties do get down with the program when it comes to moving, but yep, the mpg sucks. Our 6.0's at the airport hauled ass too, when they ran for the weight they were carrying.

 

[Driver4r]

I get 6 in town and country, im gonna guess 11-12 hwy.

 

[john55]

i was surprised i'm getting a little over 15mpg w/ a454 hard to believe but that is taking it very easy .

 

[HotRodPC]

i was surprised i'm getting a little over 15mpg w/ a454 hard to believe but that is taking it very easy .

Is that taking it easy down hill with the wind behind you??? That is good. I'd want to make sure my odometer is correct if I was getting that good. I've gotten the best of 13.6 with my 454 and that's with 3.21 rear gears @ 65mph towing nothing and no wind. Even then I was surprised to do that well, so I did check my speedo by GPS and it's spot on, and I did mile marker to marker for 10 miles and the odo was spot on too. It's running like hell right now and only getting 9 in the city, but those tall gears hurt city mpg where if I had 4.10's it would do better in the city.

 

[john55]

i didn't check it with a gps but need to it seems to run better in town i didnt drive over 30 i think it's geared low, 70 seems pushing it on highway i was told it has a new carb and tune up maybe a gps isn't a good idea it may bring me back to the real world lol

 

[HotRodPC]

i didn't check it with a gps but need to it seems to run better in town i didnt drive over 30 i think it's geared low, 70 seems pushing it on highway i was told it has a new carb and tune up maybe a gps isn't a good idea it may bring me back to the real world lol

Yeah, it's probably got 4.10's in the rear. That is the most common in the C20's. Remember, back then the speed limit was 55. If you've got 31 inch tall factory size tires on it with 4.10's, you're turning about 3300 rpm @ 70. Mathematically it's 3100 rpm but you're not in a lock up converter either, so add a bit more. Yes, at 30mph, you can probably get 15, but you sure won't get that at 70mph with the motor screaming. My 3.21 rear gears are fine on the freeway, but it struggles a bit towing too if go up a little incline and the city mpg sucks in mine.

 

[85 CA SIERRA 1500]

All I can say is; buy a Rabbit P/u if you can find one. They are gold, and have a huge cult following. Nice ones were fetching close to 10k, and a solid unmolested daily driver is worth 5k all day long.

If you live in area where they are driven on salted roads, or excessive rain, make sure to inspect for rot arond the front strut towers, the floors, and the frame rails below the bed.

Mine's a 1.6L diesel with 5spd and a/c. It'll run 75mph all day long, and keeps up with normal traffic speeds and normal traffic acceleration out onto the freeway.

It's hard to find them in nice shape, as most have had umpteen owners and by now are so ****** out that they're hard to put back into original, dependable condition. But they're out there, and usually a great value.....unless someone knows what they have, and is asking full pop.

Some examples of what mine does:

Towed another truck, with shell, and a bed full of spares and gallon jugs of engine oil, from Sacramento back here = 300mi towing about 3,000lbs

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Towing a vintage watercrasft (visit my website: www.dynafoil.com) on my 11x6 flatbed, with a 8x8 Vinyl Ketter shed in the bed.

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Moving the wife's office with the stake sides on the flatbed:

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Dude,,,,,thanks for posting those pic's,,,,,,brings back memories for me. Back in the late 80's and early 90's, I was repo-ing cars and had exactly the same set-up. VW Rabbit Pick-up and a tow dolly. The only time I used the full size tow truck was to grab non-runners.
I towed everything from Nissan Sentras to full size Dodge vans with that little rig, I still wish I would have kept it.

 

[SirRobyn0]

1984 C-20 350 700R4, I have no idea what axles are under it. It's pretty much stock, stock tire size, engine / trans, but has a well tuned edelbrock on it in place of the Q-jet. I have not been able to bust 17 on the highway best I've recorded was 16.8, which is staying right around 60MPH but I'm a lead foot. Like all these trucks from 80's the speedo ends at 85 MPH, and it has no problem getting up there, but the mileage drops off sharp much over 60MPH. On my commute which is mixed county roads into the city about 12.

 

[Paladin]

I'm lucky to get 7-8 mpg and I'm fine with that, it's a 1 ton C30 for christ's sake. I didn't build the engine for economy and I have a terrible time with my cruise control (aka "Right Foot"). I just love to hear that growl when she's strokin' heavy!

 

[OzarkRunner]

I get 10 - 10.5 pretty reliably. 1900 V1500, lifted 4", 33" tires, 3.42 rear, stock 350 TBI and 700R4. With the larger tires I only let run in 3rd gear, and still get (what I feel is) good MPG.

 

[Matt69olds]

Towing that "House", you'll rebuild that chassis 3 times around that Cummins drivetrain before you need to build the Cummins Powertrain. Did you get the NV manual trans or Aisan Auto? Dana or AAM axle in the rear,? See, Dodge don't build **** in their powertrains. Which is fine. If you can't build your own ****, at least concede and go with someone who can. Even Ford took over building their PowerStroke from Navistar. Of course they tried with the 6.0 and 6.4 too then tried blaming the failure on Navistar, then Navistar blamed Ford, and that's where that relationship fell apart, so now that Ford learned their lesson and think they don't need Navistar anymore, now the 6.7 Scorpion is all Ford. Hopefully after all these friggin years they can get it right on their own.

Chrysler transmissions are actually pretty durable. The problem is people who add injectors and programmers, but leave the transmission stock. It’s easy to add an extra 75 hp and 150 pounds of torque with some computer modifications, the transmission was never designed to handle that. Usually, the problem starts with the converter clutch. The clutch slips, overheating the fluid, the clutch debris clogs up the filter, the trans starved for fluid, and it’s all downhill from there.

My Ram has 200k on its original trans. I do have some valve body modifications done. The engine has some go fast stuff, enough to run 14:30s in the quarter mile. Not super fast, but pretty respectable for a 7400 pound truck. I change the fluid and filter once a year, and adjust the bands every 30kish miles. When it does die, I’ll probably upgrade the input shaft and install a better converter. In the meantime, if it ain’t broke, don’t fix it!!

 

[bucket]

I don't know if I posted here years ago, but here's my input anyway. I have or have had a 6 cylinder, small blocks, big blocks, 2wd and 4wd. With no towing or hot rodding, they all get about 10 mpg. They can do a little better if conditions are right, but 10 mpg is normal. The one exception is my '84 C10. In stock form with 305/th350/2.56 it could knock down around 17 mpg IF I kept it to 55mph steady cruise. Normal driving, it averaged 13.5-14.5 mpg, day in and day out.

 

[Dutch Rutter]

I figured mine out the other day. 83 k20 rebuilt 350, rebuilt 700r4, 373 or 410 not too sure but good gearing for the 33x12.5 M/Ts. Only run premium. I'm seeing 13-15 mpg pretty consistently. That's normal driving to and from work, mostly highway.

 

[Salty Crusty]

And OD trans in the square will help, but the facts are that the GMT400's are lighter and more aerodynamic.

It'll be a while before fuel "economy" starts to mean something again. A lot of squares were built with dual tanks because gas was cheap back in the day and it took 2 tanks to get most places...

 

[TubeTruck]

Mine was about 8 with the poor running 400. Swapped to a good running 350 and getting around 12, if not a hair over. Planning to add OD this year and swapping the OE intake for a Performer and 650 Holley spreadbore as soon as I get my rebuild parts. Hoping to get 13+ after some fine tuning.