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Power Wagon Fuel Economy

Posted: Fri Feb 26, 2016 11:39 am
by Danpd69
Hi everyone,

New to the forum, and currently hunting for an old Sweptline to wrench on. I'm just curious as to what kind of fuel economy everyone gets out of their Power Wagons?

I'm specifically hunting for 318 and 383 fuel economy.

Any information would be appreciated!

Thanks,

Dan

Re: Power Wagon Fuel Economy

Posted: Fri Feb 26, 2016 12:11 pm
by allsupj
Worn 318 poly, 2 bbl., 4 speed, 4.88 gears = 10 mpg maybe on a good day.

Re: Power Wagon Fuel Economy

Posted: Fri Feb 26, 2016 7:37 pm
by digdoug
10 mpg is pretty close for 318 or 383 power wagon.

Re: Power Wagon Fuel Economy

Posted: Sun Feb 28, 2016 10:44 am
by Jim100
fairly fresh 360-4 barrel headers - np 435 4.10 gears = 10 mpg
jim

Re: Power Wagon Fuel Economy

Posted: Sun Feb 28, 2016 8:00 pm
by PwrWgnWalt
Here are some of my more recent drives:
360, 4-speed, 4.10 gears = 10 mpg
(loaded = 9 mpg)
318, 4 speed, 3.91 gears = 12-13 mpg
225, 4 speed, 4.88 gears = 11 mpg
225, 3 speed, 3.55 gears = 15-16 mpg

Re: Power Wagon Fuel Economy

Posted: Mon Feb 29, 2016 11:30 pm
by WD
Late models are no better... 330hp at the flywheel TBI 5.7/700r4/NP241. 3.40 something or 3.70 something gears. Lt265/75R16E mud tires. True dual exhaust with glass packs.

10mpg empty or loaded.


D series with a 318/727/3.55 gears gets 9-11. True dual exhaust, generic turbo mufflers, LT235/75R15D AT tires.

A cinder block on a roller skate is not going to be fuel efficient.

Re: Power Wagon Fuel Economy

Posted: Tue Mar 01, 2016 6:20 am
by Jim100
"A cinder block on a roller skate is not going to be fuel efficient."

Thats a good one!

Re: Power Wagon Fuel Economy

Posted: Tue Mar 01, 2016 2:05 pm
by Danpd69
Thanks for all your input!

I was debating between a 318 or 383, depending on if the fuel economy was significantly different, but it looks like 10 MPG is about as good as these puppies get regardless of displacement.

Re: Power Wagon Fuel Economy

Posted: Mon Apr 11, 2016 11:28 am
by riffraff
My W100 was getting 9 mpg when I got it: 383, 435np, 4.10, 4 barrel, electronic ignition (and supposedly an RV cam). I put a new dual exhaust, with an A/F bung, etc, and, with a lot of work, was able to tune it down to 7 mpg, around town, at sea level :lol:

Mind you, I was aiming for economy at cruise. I'm at about 14.7-15:1 A/F cruise, and 12-13ish WOT.

I don't bother with the math, anymore....

Re: Power Wagon Fuel Economy

Posted: Mon Apr 11, 2016 8:12 pm
by sweatybetty
riffraff wrote:My W100 was getting 9 mpg when I got it: 383, 435np, 4.10, 4 barrel, electronic ignition (and supposedly an RV cam). I put a new dual exhaust, with an A/F bung, etc, and, with a lot of work, was able to tune it down to 7 mpg, around town, at sea level :lol:

Mind you, I was aiming for economy at cruise. I'm at about 14.7-15:1 A/F cruise, and 12-13ish WOT.

I don't bother with the math, anymore....
im about the same but with a 440. maybe 10mpg on a good day. i MAY drive 50 miles a month, so its no big deal

Re: Power Wagon Fuel Economy

Posted: Wed Aug 31, 2016 1:08 pm
by Kaegi
all you need to know is its better than a ford. ;/)

my 4.88 slant 6 D300 with 19.5s got 17 if I kept it under 60
my poly D300s get 10 to 14 depending on speeds and conditions. as low as 9 towing another truck on trailer.

Re: Power Wagon Fuel Economy

Posted: Wed Aug 31, 2016 1:14 pm
by riffraff
Without going out on a limb, I don't think Power Wagons have ever seen the inside of a wind tunnel....

Re: Power Wagon Fuel Economy

Posted: Tue Sep 20, 2016 6:20 am
by Drew63PW420
Hmmm, I'm new, and maybe I'm doing something wrong.
I have W200 (original 62000 miles) with 318 , stock 4 speed, don't know my gears, long tri-y headers from Stan's (Washington) new dual exhaust, stock 2 barrel, vintage Archer CDI. consistently getting 13-14mpg.
(just bought NV4500 with a 96 360 bell housing that will be going in in the next month.)

Re: Power Wagon Fuel Economy

Posted: Tue Sep 20, 2016 10:18 am
by Hobcobble
Drew63PW420 wrote:Hmmm, I'm new, and maybe I'm doing something wrong.
I have W200 (original 62000 miles) with 318 , stock 4 speed, don't know my gears, long tri-y headers from Stan's (Washington) new dual exhaust, stock 2 barrel, vintage Archer CDI. consistently getting 13-14mpg.
(just bought NV4500 with a 96 360 bell housing that will be going in in the next month.)
If your gears are original to the truck, the ratio is listed on your
VIN tag in the door jamb. :idea :2cents :Thumbsup
John

Re: Power Wagon Fuel Economy

Posted: Tue Sep 20, 2016 6:05 pm
by Drew63PW420
Word.
Looks like 4:10
:]
I'll check the milage again, too
I don't imagine I'm doing 40% bether than everybody else...

Re: Power Wagon Fuel Economy

Posted: Wed Sep 21, 2016 2:25 pm
by PwrWgnDrvr
If your speedometer is off, the odometer is also off and the MPG calc would be off.

Re: Power Wagon Fuel Economy

Posted: Wed Sep 21, 2016 11:05 pm
by Drew63PW420
Currently using late Dodge 3/4 ton 8x17" wheels with E load range tires that are about 31.5"
Offset not right but I can back it off a taste to not rub--what the heck new tires and I had them already
The radar seems right on for speed, but I'm not a scientist like my dad. The truck came with 33s the speed was indeed a bit off...

Re: Power Wagon Fuel Economy

Posted: Thu Oct 06, 2016 3:04 pm
by Kaegi
I have 2 questions. what's an A/F bung and what's an Archer CDI??

Re: Power Wagon Fuel Economy

Posted: Thu Oct 06, 2016 3:50 pm
by riffraff
Kaegi wrote:I have 2 questions. what's an A/F bung and what's an Archer CDI??
An A/F (air/fuel) bung, is simply a fitting welded into my exhaust, to allow the installation of a wide-band air/fuel sensor and monitor. In other words, I am not guessing so much about my fuel ratio. That I am only getting 7mph, is simply what the engine calls for. When I got my truck, it was at 9mph, and ran good. However, once I was able to check the mixture, I saw that it was dangerously lean at over 16:1 in some places. It had lived its entire life in a lot thinner air, at about 8000 feet, and now it is at sea-level.

I'm not familiar with the Archer brand, but a CDI ignition allows for a hotter, more precise, spark:

"CDI ignition is most widely used today on automotive and marine engines. A CDI module has "capacitor" storage of its own and sends a short high voltage (about 250+ volts) pulse through the coil. The coil now acts more like a transformer (instead of a storage inductor) and multiplies this voltage even higher. Modern CDI coils step up the voltage about 100:1. So, a typical 250v CDI module output is stepped up to over 25,000v output from the coil. The CDI output voltage of course can be higher. So you'll see CDI systems claiming coil output capability over 40,000-60,000 volts!!? As you will see this is not exactly what happens at the plug but for math purposes it works out. The huge advantage of CDI is the higher coil output and "hotter" spark. The spark duration is much shorter (about 10-12 microseconds) and accurate. This is better at high RPM but can be a problem for both starting and/or lean mixture/high compression situations. CDI systems can and do use "low" resistance coils."

http://www.jetav8r.com/Vision/Ignition/CDI.html

Re: Power Wagon Fuel Economy

Posted: Wed Nov 30, 2016 7:14 pm
by swptln
Archer CDI, holy crap....that is when Radio Shack used to make some cool stuff. It was actually a electronic kit you had to build yourself. Capacitive Discharge Ignition is basically an electronic ignition unit/system. The CDI box uses electronics to fire the coil vs using the points directly. So, the points become a trigger for the CDI box to fire the coil, reducing voltage and wear on the points/trigger and firing the coil at a higher secondary voltage 40,000-50,000 volts vs a regular point type ignition at 20,000-25,000 volts.
Not to be confused with an MSD box, not the same.