Some deep thinking on getting Best MPG in a VAN

[Ecky]

Originally Posted by racprops

No boat tail...what about deflectors to bend air into the void in back??

Without wind tunnel testing, these are more likely to do harm than good. Better to take anything and everything off the exterior of the vehicle that can cause turbulence.

My car comes stock with:
-Partial belly pan, mostly smooth underneath
-Air curtains for the front wheel wells
-Very smooth, non-spoked alloy rims
-Rear wheel covers
-Deflectors near the exposed parts of the rear wheels
-Recessed windshield wipers
-"Boat tailed" rear end, with a gentle taper that follows the shape of an airfoil
-Narrow, low rolling resistance tires, with a high recommended pressure

It was EPA rated for 70mpg highway.


On my car, my exterior aerodynamic modifications include:

-Removed mirrors and replaced with cameras / screens
-Removed rear wiper (it's in the wind stream on my car)
-Removed antenna, antenna base, rear washer nozzle
-Blocked 100% of upper grille, block 50-100% of lower grille depending on weather
-Full belly pan, front to back

There's probably some other stuff I can't think of right now. I can break 100mpg on the highway now, and have had tanks as high as ~85mpg. So, I know what I'm doing works.

Other things that are proven to help are pre-warming (e.g. oil pan and block heaters), lighter weight lubricants (I've run 0w16 oil), electrical load reduction (LEDs), warm air intake (for gas engines), higher temperature thermostat (somtimes), kammbacks, engine kill switch, accessory delete, weight reduction.

[racprops]

And a lot of hypermiling I bet.

Most of that is too extreme for my taste.

ON a van I need my side mirrors, I live in AZ so keeping a block warm is almost unneeded and as this is treated as a RV only gets driven every once in a while.

You hypermilers should look into the old Borg Warner Overdrives, they had a feature called free wheeling, it was a one way sprang that with out power to lock it up allow the engine to drop to idle, and just a little push on the gas and it would spin up and lock.

On these old overdrives a pull or push of the control cable would either free it up to free wheel or to lock up and give engine braking.

Years ago I planed on using the whole transmission, without first gear, but using the 3rd and 2nd gears as a under drive, with 3 at 1:1 being no under drive and 2nd as a under drive...with these transmissions you can engage or disengage the OD as it is its own transmissionat will so I could split all gears...

SO I would have a 8 speed with a 2 speed rear end. OR another way to look at it a 16 gear system. 8 low and 8 high.

I still have two of the OLD Borg Warner 3 speeds with OD in storage.

BUT building a shifter and mounting it the floor and the cable control and then adding a modern VSS sensor kind makes it a bit much, and adding that old cast iron tranny is another pain. AND a weight cost as well.

On the other hand converting the OD to a stand alone system has some merit.

Rich

[Ecky]

I can just set the cruise control to 55 and get 100mpg. Warm summer day with good weather of course, but well in excess of that is possible with hypermiling.

It's a 1.0L engine geared like a V8. Even in this small car it can barely maintain speed in 5th gear. The engine basically idles down the road.

[racprops]

OK which car is it?? And I forgot: "It was EPA rated for 70mpg highway." so 100MPG is only 25 more MPG than stock...that is just a improvement of 33%.

IF I can get that much improvement on my 14MPG I would be getting 18.62 MPG so reaching that should not be all that hard, the TPI is said to give 30 to 35% better MPG, now add in my new engine, and 8 speed transmission and 2.14 to 2.34 rear end, I really think I will be able to get 20MPG highway without all that extreme changes...

Rich

[19bonestock88]

Umm... 2.14 gears with a tall overdrive ratio in a van? How often do you plan on being in 8th gear? I bet not very often without some aero modding...

[Ecky]

Originally Posted by racprops

OK which car is it?? And I forgot: "It was EPA rated for 70mpg highway." so 100MPG is only 25 more MPG than stock...that is just a improvement of 33%.

IF I can get that much improvement on my 14MPG I would be getting 18.62 MPG so reaching that should not be all that hard, the TPI is said to give 30 to 35% better MPG, now add in my new engine, and 8 speed transmission and 2.14 to 2.34 rear end, I really think I will be able to get 20MPG highway without all that extreme changes...

Rich

This car:



(mine's on the right)

And yeah really I haven't improved percent-wise all that much, because the car was already pretty efficient to begin with. There are far fewer large, easy improvements. And, my car already draws a fraction of the fuel yours does. You probably save more $$$ gaining 2mpg than I save gaining 30mpg. Anything you can do will help a ton.

[racprops]

Originally Posted by 19bonestock88

Umm... 2.14 gears with a tall overdrive ratio in a van? How often do you plan on being in 8th gear? I bet not very often without some aero modding...

I am still playing around with the 2.14 to 2.39 gears, but as I alike to run at 80/85 MPH I do think I will be able to hit 8th a fair amount of time and again why I am building a engine with torque from 1000RPMs.

I have see it said it only takes 20HP to maintain 70MPG in a car so i figure it will be (?) 40HP to do the same....

First is my stock set up:

Then the 8L90 with two gears sets:

[racprops]

And here is the stock set in my 2000 Mercury with a 4.6 that was getting 30MPG stock at 65MPH, and with a lean setting of 16.1 reached 35MPG @ 65MPH, but had a serious poer drop...and running stock engine and tune with 18inch fat tires, and I still have a fast hot rod as well.

And I plan on getting the stock 2.73 gears and the second chart is the same car with them:

[racprops]

PS here is that car:

[racprops]

Also I did NO hypermileing just set cruse for 65MPH and rolled, and one test was from Phx AZ to the CA state line and back...