Fuel Saving Street Truck Start to Finish

So you'd like a little better fuel economy out of your daily driver, weekend wheeler while at the same time, make it more capable off road. Well, who wouldn't

today on extreme? We'll show you how to get it done from start to finish. It's our fuel saving street truck.

Welcome to Xtreme 4x4 and the final installment on our fuel saving street truck.

Now, we know what it's like. It's hard to have a tow rig trailer and a dedicated wheeling rig. It's a lot of investment and time and more importantly, a large investment of money. So that's why we started this project. We wanted a truck that you could drive every day back and forth to work and yet still take it out on the weekend and do some light wheels.

But more importantly, during that week long driving period, we wanted to get you as much fuel economy as we could because that's the money savings that everyone is chasing these days. Now, based on the emails that you guys have sent us, a lot of you guys out there are driving this exact same truck. 1500 series Dodge V8 underneath the hood, solid axles, front rear. They're honestly a great truck for a daily driver and a weekend wheeler. The problem is out of the box when you throw a lift kit on it and some wheels and tires, fuel economy, numbers are not that great. When we first started this project, this truck was only pulling down between eight and 10

MPG, but we were able to get it a lot higher.

Now, the first little trick we're gonna try to save a little bit of money on fuel is under the hood. Now, the V8 in this truck is just like most domestic pickups and the fact that it has a mechanical clutch fan at the front of the motor to keep the engine cool, that fan is driven by the engine as it turns and it draws air across the race.

Now, the plan here is simple. We're going to remove the mechanical fan and therefore remove that load from the engine to keep the radiator cool. We'll install an electric fan that way we'll be using power from the battery to keep our truck cool instead of power from the motor by saving that power in the motor. Hopefully that'll get us a little better gas mileage.

But

the

by removing that mechanical load from the engine, we were able to get about three extra miles per tank full. Now might not sound like a lot, but every little bit helped in this adventure to get better fuel economy. Now, for those of you guys wondering that fan was a simple 16 inch fan that we picked up from Summit racing.

Next, we put the Dodge on a diet.

We'll start with everything on the inside,

man. Whoever owns this truck is a slob.

Actually, it's, it's my truck.

I'm a sloth

79 pounds

of junk.

So our truck just lost 342 pounds. Now, all we have to do is run a few more tanks of fuel through it and come up with a new fuel mileage number.

Yeah,

so shedding all that weight saved us. How much of the pump? Well, almost a half mile per gallon. Now, not a lot, but when you couple it together with the mile and a half, we picked up with the electric fan for less than 100 bucks. We now had this truck into the double digits at 10

MPG. Now, the next upgrade not only saved us a bunch of money on fuel, but more importantly, it made this truck perform better

in the dirt.

Now, these are Dana sixties from a 1998 dodge three quarter ton. And the nice thing about these is they're a lot stronger,

the stock axles that come in the 1500 but more importantly, the gear ratio in them is different. Now, that's gonna compensate for the larger wheels and tires that are on the truck. Now, that's a serious investment. It's about 1000 bucks. But at the same time, it's gonna make the truck stronger and it's gonna make it a little bit better on fuel because of that gear ratio difference. Now, we are gonna have to change out the wheels and tires because the Dana sixties have an eight lug. So we need to put an eight lug wheel and tire on there and we're gonna take advantage of needing to do that because that is we're going to save the majority of our gas mileage.

Now by no means, are we telling you guys, do you wanna save a little bit of money on gas? Run out, buy new wheels and tires. That's kind of like stepping over dollars to pick up dimes. What we are saying is that when it's time to buy some tires, whether yours are worn out like this truck here or you're gonna change them because you're changing the axles like we are as well. Be honest with yourself, don't buy the most aggressive off road tire because you think it look

school, get a good middle of the road tire like this Mickey Thompson Baha mtz. Now, the nice thing about this tire is the tread pattern is pretty close knit. Now, that means it's gonna have a very low rolling resistance when you're driving on the highway, that'll save you a little bit of gas because it's not as much power to turn the tire with the truck. Now, since we had to swap the rims out as well. We had them go ahead and install these tires on a set of their new

17 by nine side bitter aluminum wheel in that eight L pattern to match our new data, 60 axles. Now, all we have to do is pull the half ton axles out, bolt up the new three quarter ton units, no custom fab needed because they're out of the same model truck. Once we get the new tires and wheels on there, we'll run a couple of tanks worth of fuel through this truck. Let you know what kind of fuel economy numbers we get.

We're shooting for low thirteens,

next vacuum gauge unit bearing and cable shifter upgrades. Then later we'll hit the trail. Stay tuned.

Now, if there's one universal truth, it's that we all love to save money. You guys have told us that you really like the fact that we're taking this 96 Dodge lifted street truck and trying to do two things. We're trying to make it a more capable off Roader, but we're also trying to keep more money in our pocket by improving its fuel economy by doing little things to it and giving you real world feedback. Well, so far, we removed the mechanical fan, replaced it with an electric fan and that took us from a baseline of around 8, 8.5

MPG to just over nine. Then we put the truck on a diet. We cleaned out the interior, ditched the full size spare and a bunch of junk in the bed and that got us up to about 9.5 or 10

MPG. But the big change came when we swapped the axles

by ditching the stock half ton axles and replacing them with two Dana 60 units that we pulled from the same make and model of truck. Just a little bit newer. We accomplished a couple of things. Number one, we're more confident in this truck's ability to go off road because of the larger axle shaft diameter, as well as ring gear size in that Dana 60 axle, especially in the front end. But more importantly, we now have better fuel economy. You see the half ton axles with the oversized wheels and tires. When you drove this truck on the high way, it was somewhat confused. It was always dropping in and out of overdrive, the converter would lock up and unlock and when you're cruising at highway speeds, the engine was usually turned at around 2500 RPM with our new axles. We have a 410 to 1 gear ratio. And what that does is it basically fools the truck. It honestly thinks it's still riding on stock size wheels and tires. That means that the overdrive drops in at the correct time and the converter locks up, we can cruise down the highway all day long, turning around 1500 RPM. What does that mean?

It means that we are now running at 12

MPG with this truck simply from changing the axles. Now, we could have obtained the same thing by just upgrading the ring gear in our stock axles. But then we wouldn't have that ability to take this truck off road because those half ton axles would not handle these new tires and wheels when you throw them into the dirt. Now, today's upgrade is actually pretty simple and it applies to every car out there. We're gonna change how you drive your vehicle and we're going to give you a gauge to measure your improvement.

What we're gonna be monitoring is our engine vacuum. Now, when the piston travels down inside the cylinder and the throttle is closed or your engine is idling, it's basically pulling air past the throttle blades through a huge restriction. It's just like putting your hand over the end of a vacuum. Now, that creates a large negative pressure in here pulls about 20 inches of vacuum. That's fine. The engines idling and that's how it's designed to work. You open your throttle blades up just a little bit, maybe 10 15% throttle. Your engine's still going to accelerate, the truck's gonna move down the road. It's just going to do it a little bit slower because there's not a lot of load on the engine. If you go ahead and open that throttle all the way up you lose all the negative pressure in this area and your

gauge is going to go to zero. What that means is you have a lot of load on your engine. You're putting a lot of fuel and a lot of air into it. Obviously, you're accelerating faster if you install a vacuum gauge in your truck and just monitor it. It'll tell you exactly how far you have the throttle valve opened. Anytime you're driving it, if you keep the numbers up on your vacuum gauge, you're gonna keep money in your pocket

for our truck, we're going to install an auto meter, Phantom series vacuum gauge

and to simplify the mounting process, we're going to use one of auto meters pods that

specifically designed to mount the gauge on top of the steering column, keeping it in plain view,

then we just tap into a vacuum source on the engine.

So our homemade driving coach as a vacuum gauge did exactly what we thought by keeping an eye on how we drove the truck, we picked up an extra single mile per gallon. So if you're keeping track at home with the fan,

putting the truck on a diet swapping in the axles and installing the vacuum gauge to change how we drive. We're now at 14

MPG.

Now, our next job not only saved us money at the pump, but it's going to save us in the future on our repair bill

today on our fuel saving street truck. We're gonna be doing what's called a unit bearing elimination.

And what that does is it removes this solid bearing that the tire bolts to. Because on these modern solid axle, four wheel drive trucks, whether you're in four wheel drive or two wheel drive, driving down the road,

you are always turning the shafts and all the different

components, that means more drag and less fuel efficiency. So we're going to be changing that out with a spin tech kit. And what that does is it converts the axle back over to the roller style bearings with the freewheeling hubs. We'll be able to unlock the tire and then it will just be the tire turning, no axle components get better fuel mileage.

Spin

tech industries makes these kits for either Fords or dodges any truck with a solid axle front and it's no harder to install than changing the brake rotor.

Now, this setup is actually gonna save us money a couple different ways every day when we drive it by eliminating the drive line from the tire wheels, gonna save us money at the pump. But more importantly, the unit bearing that we removed is very expensive on this dodge. This non serviceable unit costs almost $300 and you guys know that are running the

oversized wheels and tires like we are here, you go through those bearings about once every 8 to 12 months. The nice thing about the double roller bearings in this set up once a year, simply take it apart, repack them and they should be good for the life of the truck. All I have to do now is swap out the other side and then we'll take the truck out, run a couple tanks of fuel through it. But you know what we find

and what we found was the unit bearing elimination was just the icing on the cake that we needed for this truck. We picked up almost 2.5

MPG to put our final number right at around 16.5

MPG, which is amazing for a truck that's over 14 years old. Now, what we're going to do is pull this rig into the shop and show you how to deal with a two piece axle shaft.

Welcome back to extreme and today, we're not just going to focus on the fuel savings we've got with this truck, we're also going to work on a couple things to make it work better off road.

When manufacturers first brought these solid axle pickup trucks back onto the market. In the early nineties, they had a small problem as we showed you guys before they completely removed the free wheeling hubs that meant that this axle was live all the time and that hit you in the pocket when it comes to the fuel economy, how to solve that problem. They came up with a rather unique system.

They installed what's called an axle disconnect. This is a small shift fork that's mounted in alongside axle

that basically disconnects one wheel and tire from the center section of the differential. Now that got your fuel economy numbers back up because when you're driving, you were only turning one tire inside, that differential took the load off of the engine. Now, the downfall of that was how it was activated. It was activated by engine vacuum, two small vacuum lines came down to a vacuum pot. Now, that vacuum source traveled through the transfer case. When you shifted the transfer case into

four wheel drive, the vacuum came down here and engaged the two axles together with a little shift collar. Now, the problem with losing vacuum to supply that source is engine vacuum. It changes all the time whether you're on the throttle or off. Now, that means when you need this axle, the most climbing that big tall hill wide open throttle, you have a chance of losing vacuum down to this axle disconnect and therefore you'll lose your four wheel drive in the front axle, but there is a way to solve that problem.

So we're gonna ditch that vacuum set up and replace it with a 100% mechanical connection with a kit that we got from Posi

Lock. Now we'll replace that small housing that mounts to the front axle and instead of a small vacuum pod, we'll hook up this heavy duty, Morse style cable and run it inside the passenger compartment of the tree.

That way, whenever we want that front axle locked together, all we have to do is pull out on the cable and we know we have true 100% 4 wheel drive. When we're ready to go back in a two wheel drive, we'll just push it in and then we'll disconnect that front axle, giving us that two piece axle shaft assembly and it's easy to install just bolt right in place.

The first step of the installed is to remove the factory axle coupler and clean the gasket surface.

The new posi

box system bolts right up to the axle

and then the cable is routed into the cab.

Now, whenever you wanna engage the front axle, all you gotta do is pull the cable to lock the two piece shaft together.

Now, every other project we've done to this truck, we've told you that we'll run a couple tanks of fuel through it and let you know what kind of fuel economy numbers we come back with. But this last little job we've done here has nothing to do with our fuel mileage. The only reason we installed that Posi

lock into this rig was to prove its ability off road and there's only one way to test that

we're going four wheelers.

You're watching Xtreme 4x4 for a DVD copy of this episode, just go to Power Block tv.com and order your copy for just 595 plus shipping and handling. Start your own Xtreme 4x4 collection delivered right to your door from the power block.

Welcome back to Xtreme 4x4. Now, we've already proven that this truck saves us money when we're driving on the street. Now, it's time to see how it handles a couple of trails.

Ha.

That's not baseball cards on my folks.

I gotta grease that U joint

next time

next,

when you're wheeling a truck like this with an open front de

you really gotta choose where you're gonna go because traction on the front end is somewhat limited.

I don't know if I'm gonna get up this hill.

Oh,

yeah.

000, there's

tree there

be smart when you're on the trail with your daily driver.

If it looks like it's gonna tear it up

sometimes it's best just to back on down.

So there you have it, guys. Our fuel saving street truck has done everything we've asked it to do.

It's great to drive every day, getting fuel economy in the high teens and best of all you can still take it out on the weekend and conquer some trails.