ChinaLakePW
Member
My 2018 is completely stock. I averaged 11.9 towing 4.1K from Florida to California. Best tank of gas has been 16.1 (all highway). Lately I have been in the low 11 MPG range, but I have been off road a fair amount.
Eating crow....2018 Ram Power Wagon build
- Thread starter Tex68w
- Start date
Tex68w
Beach Bum
Nice, I make my way out to The Bomb Diggity once or twice a month and of course I come through there on my way up 59/69 heading to Houston. What are you driving?
This is a snapshot of what I see on most road trips/highway travel in the PW when traveling at 70mph (speed GPS and mathematically corrected for tire size to 63mph). I have 37x13.50x17's which are 11.68% larger in diameter than the factory rubber. This equates to a -10.46% speed variance. If you take the 14.3mpg average seen in the pic (it's usually more like 14.7-14.9mpg) and multiply it by .1046 you get an adjusted 15.79mpg's (16.46mpg if you use the 14.9mpg average I see more consistently).
In town I see roughly 11mpg on average, corrected that's actually 12.15mpg, not the best, but no worse than the 4Runner and Land Cruiser on 33's we had a few years back. The range estimate shown is based off of the previous tank where I averaged under 10mpg's due to the majority of my travel being under 15mph off-road at the ranch.
Obviously there are other factors to consider like the increased rotational mass from the heavier wheel/tire combo, increased drag from the larger contact patch, and reduced aerodynamics from the higher vehicle and increased air flow underneath. The lie-o-meter is not always consistent when compared to real world calculations and I have no idea how far off the computer is on these trucks, but I will be sure to hand calculate the next interstate travel tank with the -10.46% variance for comparison. On a recent trip back from the coast I tried setting the cruise to a shown 57mph which is actually 63mph when corrected for the larger tire size. I averaged a shown 15.7mpg's on that 60 mile run which is 17.3mpg's when corrected, a small improvement but 1-2mpg's more for a 5-7mph reduction in speed isn't half bad if I have the time to go slower.
I don't know about y'all, but that is more than acceptable milage in my book for a 7000lb truck on 37's. How does your PW/Cummins compare?
I think your best bet is to use a gps to determine the miles traveled and divide it by the gallons used.
Using the variance method and going off the trip computer may only give you approximate results.
Sent from my iPhone using Tapatalk
Ducky's Dad
Explorer
I used to hand calc the mileage in my PW, until I realized that the computer was giving the same numbers as my math. Only variance was due to tire size change and I can do that in my head.
Tex68w
Beach Bum
GPS, hand calculated, and variance are all within .10-.20mpg of one another. I've done the math backwards and forwards and it's all very close, which tells me that the Ram computer is actually very accurate.
ttengineer
Adventurer
rehammer81
Active member
I hand calculate my mpgs every fuel up in an app on my phone and my computer estimate is regularly 1 to 1.5 mpgs high compared to the hand calculations. I'm basically averaging 13mpg hand calculated in mixed town/hwy driving on the stock 33s. I do have an RTT on the back now but I really haven't seen much change since I installed it. One thing that I think really screws up the on board computer is that I typically really top off my tank and try to squeeze as much fuel in as possible. I think that extra fuel beyond pure tank volume might jack up its calculations.
Sent from my Moto G (5) Plus using Tapatalk
Sent from my Moto G (5) Plus using Tapatalk
ttengineer
Adventurer
It’s only going to be accurate if you top off to the exact same level every time. I basically top off till I see fuel in the filler neck. The volume is so small at that point that the difference is negligible.
Sent from my iPhone using Tapatalk
rehammer81
Active member
That's what I do also but the computer and hand calcs do not agree ever.
Sent from my Moto G (5) Plus using Tapatalk
Sent from my Moto G (5) Plus using Tapatalk
You know what's ridiculous? The computer knows exactly how much fuel is being metered into the engine and how far the odometer turns so this shouldn't be that hard to get right, or at least consistently wrong. My Yamaha outboards have a digital fuel meter built into the gauge that is consistently within .25 of a gallon of fuel used over 40 gallons or more. It normally is closer to .1 gallon on a fill up. That the manufacturers can't even make these economy meters consistent is ridiculous.
73Carlow
New member
This is a snapshot of what I see on most road trips/highway travel in the PW when traveling at 70mph (speed GPS and mathematically corrected for tire size to 63mph). I have 37x13.50x17's which are 11.68% larger in diameter than the factory rubber. This equates to a -10.46% speed variance. If you take the 14.3mpg average seen in the pic (it's usually more like 14.7-14.9mpg) and multiply it by .1046 you get an adjusted 15.79mpg's (16.46mpg if you use the 14.9mpg average I see more consistently).
In town I see roughly 11mpg on average, corrected that's actually 12.15mpg, not the best, but no worse than the 4Runner and Land Cruiser on 33's we had a few years back. The range estimate shown is based off of the previous tank where I averaged under 10mpg's due to the majority of my travel being under 15mph off-road at the ranch.
Obviously there are other factors to consider like the increased rotational mass from the heavier wheel/tire combo, increased drag from the larger contact patch, and reduced aerodynamics from the higher vehicle and increased air flow underneath. The lie-o-meter is not always consistent when compared to real world calculations and I have no idea how far off the computer is on these trucks, but I will be sure to hand calculate the next interstate travel tank with the -10.46% variance for comparison. On a recent trip back from the coast I tried setting the cruise to a shown 57mph which is actually 63mph when corrected for the larger tire size. I averaged a shown 15.7mpg's on that 60 mile run which is 17.3mpg's when corrected, a small improvement but 1-2mpg's more for a 5-7mph reduction in speed isn't half bad if I have the time to go slower.
I don't know about y'all, but that is more than acceptable milage in my book for a 7000lb truck on 37's. How does your PW/Cummins compare?
Our mountain minivan is a 2018 2500 Crew Cab OffRoad 6.4 Ram with Carli suspension, 37" tires and both my wife and I drive it pretty hard. Averaging about 14mpg in town and about 18 mpg on the highway. Basically the same rig as a power wagon minus the weight of the winch, not sure the sway bar disconnect and lockers would effect weight all that much. Beautiful ride
Tex68w
Beach Bum
I finally got around to finding some time to get at least some of the lights installed on the PW yesterday. I ended up going with BD Squadron Sports for the fog pocket, one wide angle in amber and a driving combo in white. As high up as these trucks sit I didn't see the need to have blindingly strong lights in that location. Trust me when I say that the Sports are plenty bright as it is. Install was a breeze once I figured out which direction I needed to place the brackets in order to flush mount them inside the pocket instead of the protruding look like the instructions recommend. Kudos to @marshal for the heads up on flipping the lenses around prior to install.
I installed the SDHQ A-Pillar/windshield brackets as well. Once I get around to installing the Aux switch panel I'll get the XL80's mounted up there.
I am considering mounting a 20" light bar behind the grill in this location, but I'll have to do some investigating and see what it'll require to make a bracket work in that space. I am not sure I'll need anymore light once the XL80's go on, but I think it would make for a clean install if I can figure it out. Has anyone attempted this yet?
I installed the SDHQ A-Pillar/windshield brackets as well. Once I get around to installing the Aux switch panel I'll get the XL80's mounted up there.
I am considering mounting a 20" light bar behind the grill in this location, but I'll have to do some investigating and see what it'll require to make a bracket work in that space. I am not sure I'll need anymore light once the XL80's go on, but I think it would make for a clean install if I can figure it out. Has anyone attempted this yet?
Kingsize24
Well-known member
Looks awesome Jeremy! Interesting spot for a light bar. Looks like it would be a good one if you can figure out a sturdy mount for it.