Community thoughts
 

Goodafternoon,

We are a family of 8, so we own a 12 passenger van . I'm wondering if anyone has attempted anything to try and improve fuel economy in a vehicle this large. I've set the tires to 70psi (max would be 80) anything higher makes for a very harsh ride . We've been diligent on maintaining it but I'm always open to different ideas to get some savings at the pump.

I'm fairly certain the writing is on the wall with this particular vehicle but I wanted to ask.

What does it say on the wall?

The answer you request is yes. but to be specific would require a specific vehicle and a use case.

Could you tolerate a three foot bustle on the back? Could you tolerate a single-wheel trailer on long road trips?

It would help if you told us the year and maker of your van
which engine and transmission you have. Is this carbureted or fuel injected? Does it have an overdrive?

When was your last tune up (plugs? cap & rotor? spark plug wires? Air filter?)

And yes, people try to improve their fuel economy on motor homes all the time. Yes, there is always some improvement to be had. The fuel $ savings on big rigs is substantial, since they consume so much fuel.

Going from 10 mpg to 12 mpg is a 20% improvement and will save you 20% on fuel, which would be significant if you drive a lot.

The biggest improvement you will see in a driving a big giant brick is to reduce speed. There is probably a 20% increase in mpg in slowing down to 55 mph from 65 mph.

If your car is newer than 1996, get yourself a Scan Gauge II or other real time mpg monitoring device. Changing your driving habits by watching the gauge can save you another 20%.

Lawn edging air dam.

Splitter with air curtains.

I like where freebeard is going with a single wheel trailer. I'm envisioning a cargo box mounted to a hitch that also improves aero by filling some of that void space in the rear.

I'm guessing someone with a family of 8 isn't willing to custom fab a hitch mounted cargo box, so something off the shelf is likely preferable.

https://cdn11.bigcommerce.com/s-b5lj...326796.jpg?c=2

Regarding driving slower, there's no chance I'd consider that with a family of 8. You've got 8 lit fuses there, time is of the essence. Every 1 minute longer it takes to reach a destination is 8 minutes of life consumed.

Last week I saw a Ford Econoline from the '80s, and it sounded clearly to have been retrofitted with an "agricultural" Diesel engine, most likely also backed by a manual transmission. Too bad I wasn't quick enough to pull the phone from my pocket and snap at least one picture... On a sidenote, full-size American vans are quite oversized anyway compared to other vans that I used to see as some sort of benchmark for 12-seater vans.

We own a cargo carrier we've pondered selling, but I may have to read up on it's usage for these improvements.

Sorry I thought I had included those specifics.

We own a 2007 E350 Superduty , 12 passenger auto 2wd with the 5.4L with OD.

We had the plugs all replaced, within the last 10k. Coils were tested individually and all are working as they should be ( per Ford ). Air filter was replaced just 6 months ago ( approx 5k ago ).

Going to change the oil in the next few days.

I'm just now starting to track my mileage after joining this site , so I can obtain some idea of where we are at .

The wall reads "you are driving a brick with seating for 12... quit complaining " lol

I do t know the specifics about your vehicle, but you’ve got a lot more room for improvement than someone driving a Prius. A 10% improvement in your van is going to save a lot more money than a 10% improvement on a Prius.

I'm still new to this world, so I'm only going of info I've obtained from the Econoline forums I've been part of.

Had this engine been at least as popular as the SBC among off-roaders, sure there would be more builds oriented toward low-end torque that you could replicate and match with a higher differential ratio

Just checking: it's a passenger van, not some weird excursion variety. So aero is your devil. Brick wall in the front, huge vortices behind you, the side mirrors are probably worth a 2mpg penalty just by themselves.

80 psi tires means 6ply or better, probably another 1or 2 because they are heavy and not designed for fuel efficiency or low rolling resistance.

You're mantra should be clean up the flows around and below the vehicle. The people here know their stuff, welcome.

And no reason you can't improve the mpg. Wont be 30, but it will be better than you get now.

Retractable boat tail, side skirts, and a half-circular front bumper (no pic from the front)https://ecomodder.com/forum/member-f...pe-ii-boat.jpg

I made this for another thread. Half-rounds chamfer the stagnation point like the Cybertruck and bellmouth the radiator, mirrors moved away from the A-pillars, side skirts, Cruiser skirts and a boxed cavity.
https://ecomodder.com/forum/member-f...-1224-copy.jpg

Attachment 32443

Here's a side shot of our 07 Econoline.

I may start carrying the cargo carrier we have on the rear hitch like was suggested . Just need to install it in between work and packing for our move.

Be aware that the hitch box shown by redpoint5 does what's called 'wake filling'. Some benefit, but not as much as if there is a smooth transition off the vehicle body.

Would you be more inclined toward skirts or lowering?

It really would come down to usability for our household, and living in Northern Wisconsin I wouldn't know how either would handle the changes in weather and seasons .

I'm thinking conveyor belt style front dam, underbody lining to smooth flow, side skirts and some flow separation at the back.

I don't see any full-size truck, van or SUV with anything below 8PR so often. And even some 8PR 185R14 tires for VW Kombis are already quite heavy...

Attachment 32491

Attachment 32491

Attachment 32492

In between packing and digging through our garage my wife and I got around to installing thr carrier on the E350. Due to the move it can't be permanently installed. However once this move is completed it will be installed
Any additional suggestions would greatly be appreciated.

Putting the cargo box behind the van instead of on top is a smart move, much better for aero.

If you're looking for something cheap and simple, you could grab some garden edging as mentioned earlier and make yourself a front air dam. If you can encourage air to go around the van rather than under it, that will improve aero.

You could also grab a piece of pipe insulation and stuff some of it into the front grille. Once again, encouraging air to go around the van instead of through the engine bay will improve aero. Just be careful not to block too much of the radiator. You wouldn't want to overheat the engine.

First, get rid of that passenger step, that is a real aero killer and causes a lot of turbulence.

The modular 5.4L and OD, is a good high torque truck motor with reasonable gas mileage for big vehicles. You can get a SCT tuner and get a custom tune with more ignition advance to run on only premium fuel, which will bump your gas mileage maybe 10%. With currently premium about 5% more than regular gas, this is a small savings. Long tube headers would be your best add on, if they make them for the van. They won't be cheap though $1000, but long tubes add quite a bit of torque through the cruising range and better mpg at cruise.

You can do what is called a J-mod to your trans. I assume you have the 4R70W. The J-mod removes a couple of springs in the control body that eliminates slow 1 to 2 and 2 to 3 shifts and also drill a few holes in the control body plate larger. So basically a shift kit that gives you a faster and harder 1 to 2 shift and a 2 to 3 shift.. You will save fuel accelerating since you minimize clutch slippage and gets you to cruising speed faster on the same amount of fuel.

Your mirrors are huge but IDK if there are better easier options for you.
If you could lower the vehicle 3", that would help, and add a front air dam off a suburban or other vehicle.

Then run about 5 psi less than the maximum tire pressure. Since you probably have 120 load rating tires, that would be 75 psi or so.

receiver-hitch-mounted boat tail
 

If this link works, this will be a concept for something attached to the cargo carrier.
It's an aerodynamic boat-tail, one of the few things which will add significant mpg on the open road.
https://ecomodder.com/forum/showthre...ail-29754.html
The tail is shaped to help the divided streamlines to come back together, minimizing the drag-inducing turbulence behind a squareback shape.

I was thinking the easiest mod would be to taper in sides and bottom to the cargo box. The roof looks more difficult.

some Econoline numbers
 

I found some of the original road test reports for the 'all-new' Econoline when it hit the market as a 1992 model.
* 7-12 passenger
* nine different powertrain options
* 200-265 horsepower
* Curb Weight - 5,138 - 6,261 pounds
* Length- 211.8" - 231.8"
* Width- 79.5"
* Height- 80.9"
* Ground clearance- 8.2"
* Tires: 235 / 75-15
* Cd 0.39
* Frontal area approx. 38.9 sq-ft ( 3.6139- meters-squared )
* CdA approx. 15.171-sq-ft ( 1.409 meters-square )
* 35-gallons ( range: 350 - 539 miles to fuel starvation )
* 10-mpg to 15.4-mpg depending on powertrain
* 27-horsepower Road Load at 50-mph ( CAR and DRIVER coast-downs )