Some deep thinking on getting Best MPG in a VAN

[freebeard]

Aluminum body. With a chalk line and a angle grinder you could give one an engine-turned finish. Maybe just the side panels?

[JSH]

Originally Posted by racprops

Well when I consider how bad the TBI system is, that a TPI stock is rated to give 30% better MPG which if true that works gets me to 18.2…on a bone stock engine, now add in my changes to a new strong 383 tuned for lower RPM Torque, add in the modified PCM with a lean burn cruse, I think I will hit 20+ MPG.

NOW add in the 8 gear auto and the high rear end with a 2.14 to 2.23 I think I will be able to see much more…

Rich

If you are shooting for 20ish mpg highway I would just swap in a Chevy 4.3L V6 and call it a day. Your 1993 G20 with the 4.3L was rated at 20 mpg highway from the factory. 4.3L V6's are a dime a dozen in junkyards.

I've done 20-22 mpg with my 2004 Chevy Astro (before the lift)

[freebeard]

I did a sketch for someone else in another thread and I was so appalled at the result I though to try again. So as promised in Permalink #105:



Bad lighting and I stopped drawing when it started getting worse. I didn't call them out in the diagram but the features are:

• A slant chop in the fiberglass topper. The pie cut is inside the angle on top and then a curve down to the drip rail. Gap filled with a quarter-round.
• A turnpike-cruiser type fender skirt that covers the sanitary drain and extends to the extreme rear.
• A rear deflector, as you asked about at Permalink #40. See below.
• The clear plastic rounded front corner. The inner half forms a bellmouth to the grill opening and the outer half needs more thought to form an air curtain.
• Swan-neck mirrors on a blister over the dirtiest part of the a-pillar, the top door hinge.

The Recumbent Bicycle and Human Powered Vehicle Information Center via https://ecomodder.com/forum/showthre...tml#post271093

Additional mods for Vans and SUVs::
A new spoiler design has been shown to reduce drag and lift significantly on bluff-backed vehicles such as minivans and SUVs. Simulations showed that aerodynamic drag on a mini-van moving at 67 mph were reduced by 5% when the new spoiler was attached. This rear spoiler acts like a diffuser when it is attached to the back of a vehicle, making the pressure on the back of the vehicle higher than without it. That's a good thing!

Full technical paper ($22)
A Rear Spoiler of a New Type that Reduces the Aerodynamic Forces on a Mini-Van

I don't know about this but it's got kach22i's attention and that's recommendation enough for me to consider it. Apply it across the rear top and down both sides to the fender skirts.


http://i.ebayimg.com/images/i/191693...-1/s-l1000.jpg

This VW swan neck isn't forward-reaching, but there are others available for street rods.

[Phileaux4]

Once the engine is installed you should find the base line for engine fuel consumption. Here's an article from '09 Mother Earth News:
motherearthnews / green transportation /100mpg car
He ran the engine at hwy rpm in park and measured fuel usage. The difference between that and actual mpg is friction and aero drag.
You don't want to go chasing the unattainable.

I can't post the link but that should be enough for a search.

[Piotrsko]

Originally Posted by racprops

Very interesting. As I live in 110 degrees AZ, I fear blocking my grill for causing over heating....

Do you remember the 1960 series Dodge econoline with the radiator in the hotbox with the engine? I don't recall them overheating in Yuma in the summer. I also don't recall having killer A/C either, but....

[Shawn D.]

Originally Posted by Phileaux4

He ran the engine at hwy rpm in park and measured fuel usage. The difference between that and actual mpg is friction and aero drag.

That sort of test is useless. You can't extrapolate from a no-load situation to a loaded situation by simply adding friction and drag. Throttle position, manifold vacuum (or pressure), ignition and fuel mapping, combustion temperature, and pumping losses will all be significantly different.

[Phileaux4]

Originally Posted by Shawn D.

That sort of test is useless. You can't extrapolate from a no-load situation to a loaded situation by simply adding friction and drag. Throttle position, manifold vacuum (or pressure), ignition and fuel mapping, combustion temperature, and pumping losses will all be significantly different.

(My wrighting is't as clear as my thinking)
Yes with all of the accessories running in the car. If he knows the van will run 1,800rpm test it there. From the testing he'll know "the best possible is Xmpg".

[Shawn D.]

Originally Posted by Phileaux4

(My wrighting is't as clear as my thinking)
Yes with all of the accessories running in the car. If he knows the van will run 1,800rpm test it there. From the testing he'll know "the best possible is Xmpg".

That doesn't make the test any more valid. All of my critiques of the validity still apply.

Originally Posted by Piotrsko

Do you remember the 1960 series Dodge econoline with the radiator in the hotbox with the engine? I don't recall them overheating in Yuma in the summer. I also don't recall having killer A/C either, but....

You've combined the names of the Dodge A100 or Ford Econoline. There was also the first-generation Chevy Sportvan, which had the same configuration. They all had large ducting going to the radiator that was in the doghouse with the engine. Also, they were new back then and folks' memories fade about how unreliable vehicles were; overheating was much more common across all vehicles, so them overheating would not have been notable.

[kach22i]

Originally Posted by JSH

If you are shooting for 20ish mpg highway I would just swap in a Chevy 4.3L V6 and call it a day. Your 1993 G20 with the 4.3L was rated at 20 mpg highway from the factory. 4.3L V6's are a dime a dozen in junkyards.

I've done 20-22 mpg with my 2004 Chevy Astro (before the lift)

I have that engine in my 1998 S10, something like 245 lbs of torque, fun to drive.

Intake manifold gaskets go at 75K, I'm told the aftermarket ones are better/thicker than stock and are superior. I used some goop and clogged up my heater core, live and learn - did fix the problem, more like an exchange of problems.

1. Take weight out of the van if possible.

2. Improve aerodynamics where possible.

3. Many of the aerodynamic improvements add a tiny amount of weight but are worth it.

The large chin spoiler I once added to a 1976 shortbox Ford van did not improve MPG, but it did tame cross winds and made driving more enjoyable.

If I ever got a van again I would make it look like a big rig with the rear baffles forming a box cavity.

Like these:

https://gajitz.com/happy-tails-simpl...ficient-wings/


https://ecomodder.com/forum/showthre...g-36038-6.html


Or this:

https://ecomodder.com/forum/showthre...g-36038-6.html

[Galane]

GM often made the engines for trucks less powerful than the same engine used in cars. Dunno why. An upgrade for the S-10 or S-15 was replacing the 2.8 or 4.3 V6 with one from a Camaro.