Reducing drag on a service van...

[lortech]

I am in the Data, Phone, IT business. I install hardware all over Vancouver and some times, go on long out of town trips. I am in need of upgrading my vehicle to a more professional service van vs my crappy looking 80s diesel land cruiser. The one in question looks like this. The regular fiberglass ladder made by warneer would be replaced by a little giant that would be placed inside the Van.

Does anyone know what the Cd on thsi van is, and how much drag can be reduced? Can one or two cylinders be shut off while in cruise mode and if a kit can be purchaced to do this?

[BabyDiesel]

The Dodge Caravan has a Cd of 0.35

I found it here --> Vehicle coefficient of drag specs - Mechanical Database

It is entirely possible to drop your drag by over 50%. It depends on how far you want to take your modifications

I do not know of a cylinder deactivation kit. That is a pretty drastic mod that could result in catastrophic failure. Focus upon the proverbial "low hanging fruit*" first, then reach for the stars

*Air dams, grill blocks, increased tire pressure

[serialk11r]

I'm no expert on (lol oops, said "GM" but I guess it's) American engines, but I bet that engine is shared with a lot of cars. Check the hot rodder forums to see if tuning the ECU is easy. Get a narrowband O2 emulator and run it lean, it'll save you a good amount of fuel while not being as risky as shutting off cylinders.

[lortech]

also, running the engine on lean will cause the valve seats to to burn. I have been a auto mechanic for years, but got out of its mostly. Shutting off the injector on one or two cylinders while in cruise is a good idea. Sure, it will send more unburnd oxygen to the O2 sensor, so some form of modifying the input of the sensor to the ECM would have to happen. Taking in Map sensor values, TPS sensor values so when to shut off and turn on the injectors so to prevent engine shake is something to be considered. A trailer that matched the exact outside width and height of the rear side of the caravan and taper to a boat take would cut drag considerably.

[dirtydave]

I had a 1999 dodge van when I started ecodriving. best tank was 33mpg empty with only the front seats, no other interior.

perfect work van IMHO

[euromodder]

See where you do most of your miles.

In the city, you'll benefit most from weight reduction and driving technique.
Check out the tips here :
100+ Hypermiling / ecodriving tips & tactics for better mpg - EcoModder.com

On the open road, drag (and speed) reduction helps.
Not using a roof rack is a good choice - these are really a drag.
Speed - on longer trips the reduced fuel consumption will not pay for lost wages due to being in the car rather than on the job.

Increased tyre pressure helps everywhere - crank it up to the psi for max. load for starters, then increase bit by bit.
The ride will get harder, but should never become bouncy.


An air dam is a none-too-obvious feature to cut drag
These vans are already fairly well streamlined as vans go.

Can you get these with a manual transmission ?

[lortech]

Be cool to put a vw diesel inside one of these. The ideal mini van of course, lower head room for lower cd. Narrow van put the crash bar on the outside of the drivers door and put a plastic cap to make it look decrative. that would make van 4 inches narrower. Make it longer and taper the back end to more boat like design. The hatch would have to have a big chunk of the tip built into it so, you can have a flatter floor.

One wild departure from closed wheel well is to shrink the side walls of the van to the edge of the inside of the tires and place a cap over the wheels.

Make the windshield rack more inline with the hood.

[redneck]

.

Are you trolling...???

You have a total of five posts in two threads. Members here have given you great answers and advice in both threads. Yet, you don't seem to acknowledge any of it.






>

[Hersbird]

We have had almost every style and motor of a Caravan and hands down the 2011 up new 3.6 gets the best economy. Just setting the cruise at 65 it will pull 29-30 mpg, 55 goes into the 30's. The next generation will add a 9 speed, direct injection, better areodynamics, and even a hybrid. Still over a year out though and will be more expensive. For that van there is no cylinder deactivation that wouldn't cost more then a newer van and yeild lesser results. They did make these vans with diesels for overseas markets but agian I bet a swap would be much more expensive then just getting a new one. Fleet pricing on a brand new 2015 cargo version is under $20,000, as low as $17,000. Find a used 2011 and it should be 9-13k.

For your van lose the roof rack, max the tires, and keep it under 65.

[aerohead]

Originally Posted by lortech

also, running the engine on lean will cause the valve seats to to burn. I have been a auto mechanic for years, but got out of its mostly. Shutting off the injector on one or two cylinders while in cruise is a good idea. Sure, it will send more unburnd oxygen to the O2 sensor, so some form of modifying the input of the sensor to the ECM would have to happen. Taking in Map sensor values, TPS sensor values so when to shut off and turn on the injectors so to prevent engine shake is something to be considered. A trailer that matched the exact outside width and height of the rear side of the caravan and taper to a boat take would cut drag considerably.

If you haven't seen BamZipPow's boat tail based on a 1-wheel trailer thread at the AERODYNAMICs Forum you should check it out.
He's been able to add a few mpg by towing his boat tail.
I'll try for some images to illustrate the concept.




Here's a link to Bam's site
http://ecomodder.com/forum/showthrea...ler-26997.html