Modifications To Improve Gas Mileage (6 Viewers)

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MUDZLLA

MUDZLLA

Joined
May 26, 2008
Threads
47
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730
Location
Leduc County, AB
Does anyone have any advice on improving mileage on the 4.7L V-8? I have the 2006 with VVT and my results are inline with other discussions: about 11.5 city/ 13 hwy. I'm running 33" BFG A/T's and a gamiviti rack. Not much else but a jack hanging off the side. Anyway if there are any good threads on the subject or recommendations out there I'm open to suggestions.

I don't want driving tips just suggested modifications that work and are cost-effective without hampering capability.

Regards and thanks for any tips.
IMG_8479.jpeg
 
Aside from good maintenance and 91 or better octane fuel I'm not convinced there's much out there unless you want to start screwing with ECU tuning or somehow leaning the mixture with some sensor trickery.

I expect someone to mention the 12-hole injectors, but we still haven't seen solid long-term (a few thousand miles before and after) data on that so it's a bit of an unproven theory for me.

The 33" KO2 tires, bumper and roof rack are probably more detrimental than anything you could do to counteract them. I'd just let go of the idea and enjoy it the way it is. :)
 
If you look at semi trucks these days they are going with aerodynamic improvements to get better mileage. They are using air dams, skirts, rear fairings. Expect the most improvements will be down this road. Lifted, bumpers that put tires (larger) in airflow, roof racks, stuff mounted on top and in back, creates a lot of drag. The trick will be coming up with significant fairings that you can fold up and stow for offroading. Don't think it will be pretty, but art is in the eye of the beholder. :clap:
Air flow drag under the truck and breaking over the back end of the box are significant.

semitruck-aerodynamics.jpg
 
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At your current setup - bumper and winch, roof rack (added weight) and rolling resistance of our AT tires, your fuel consumption is just about right. Fuel consumption’s number one adversary is weight.
 
Yeah... that's what I figured. Had a mini blizzard here yesterday and people were sliding off the glare ice roads in droves. The tank just rolled on through.

I like the improved injector idea - there have been technology inroads there, particularily with pre-ignition chambers. I thought maybe someone has had expereience with high performance multi-spark coils as well that claim to improve efficiency.

Opinions seem to vary on switching to high octane fuel. It's 20-25% more $$$ here. Seems the cost/benefit ratio just isn't there.
 
Skidoo said:
If you look at semi trucks these days they are going with aerodynamic improvements to get better mileage. They are using air dams, skirts, rear fairings. Expect the most improvements will be down this road. Lifted, bumpers that put tires (larger) in airflow, roof racks, stuff mounted on top and in back, creates a lot of drag. The trick will be coming up with significant fairings that you can fold up and stow for offroading. Don't think it will be pretty, but art is in the eye of the beholder. :clap:
Air flow drag under the truck and breaking over the back end of the box are significant.

View attachment 2490323
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All of those improvements on a big truck will net you about .1-.2 mpg improvement. It will take 500,000 miles to recoup the cost of the aero aids and the small lose of weight carrying ability due to the weight of the mods. In my years in fleets I have never seen any claims higher. rolling resistance of the tires is also a factor. You could get batter mileage on a big truck by rolling back emissions to 01-05 standards. That seems to be the sweet spot. In 06 emissions went to a higher standard and mileage dropped on big trucks by about 2 mpg.
 
OEMGUY0720 said:
At your current setup - bumper and winch, roof rack (added weight) and rolling resistance of our AT tires, your fuel consumption is just about right. Fuel consumption’s number one adversary is weight.
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I would bet a conversion to a more street oriented tire would make a nice improvement in mileage. Something like a Michelin defender. Small mud flaps in front of the front tires will improve mileage as well. panel gap and roof rack removal.
 
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"I would bet a conversion to a more street oriented tire would make a nice improvement in mileage. Something like a Michelin defender"

Yeah but sort of defeats the whole purpose for me. I tossed the 20" rims and Michelins as soon as I could in favour of 16" rims and the 33s. This is Canada remember. Guess we can't have it all.
 
MUDZLLA said:
"I would bet a conversion to a more street oriented tire would make a nice improvement in mileage. Something like a Michelin defender"

Yeah but sort of defeats the whole purpose for me. I tossed the 20" rims and Michelins as soon as I could in favour of 16" rims and the 33s. This is Canada remember. Guess we can't have it all.
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I understand that but the battle between capability and off road ability is real. I converted the 200 to RW's and BFG's I understand the problem. There is a not an easy solution. I have accepted my fate
 
Weight will only affect city (stop/go), as inertia (rolling & weight) is a bigger factor @ low speed stop & go. Can't do much here as the empty weight is quite large on these rigs. Street tires help here, though too lazy to calc out that affect.

Air resistance contributes due to the vel squared. That's where aerodyanic improvements pay off. Stash all the gear inside, lower the rig (if u have that height adj system), switch to street tires, close all windows is what will work @ speed (let's say over 55mph). Go at it 😭
 
I think it can be an every car thing. this is the wrong car to care about it though.
You also can't argue that reducing weight doesn't increases MPG in all instances for the same vehicle, any weight any C of D.
True?
 
Anecdotally, I get better gas mileage by increasing tire pressure.
 
I am having an intermittent MPG issue where, along the same route (100-200mi), I am varying MPG by ~1-1.5 mpg towing my trailer. I get between 8.5-10mpg depending on the trip. I didn't replace my fan clutch when I did my TB and am wondering if that is the culprit. I can't prove this as I haven't replaced it yet but it's on the list to do shortly.

Just adding some food for thought... could be something mechanical on the front of the motor
 
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