2003-2009 4runner eco mods
 

So basically i am looking to possible purchase a newer generation ie: 2003-2009 Toyota 4Runner 4x4 4.0L 5 Speed Automatic.

However before doing so i want to check with the gurus here and see if it is possible to achieve better than OEM/EPA ratings.

With that regard the SUV in question that I am thinking about is rated for 17 City and 19 Highway.

So my question is do you believe it is possible to attain 25 MPG Highway. As i currently drive 50 miles round trip everyday for work.

My anticipated modifications would likely be the following.

Aero Hitch Mounted Kammback
Folded Passenger Mirror
Max Out Tire Pressure
Front Air Dam
Front Grill Block
Electric Fan
Full Flat Bottom
Rear Fender Well Skirts (maybe)
Smooth Wheel Disks (maybe)
Scan Gauge


Please let me know what your thoughts are.

Get the ScanGauge (or UltraGauge) as your FIRST mod.
It will give instant feedback and tell you what works and what doesn't. It will also assist you in "adjusting the nut behind the steering wheel" (the most cost-effective mod - it's free).

Coming from a fellow 4Runner owner, I would say that doing more than EPA rated is definitely possible. I sure hope 25 MPG is doable, because I have a similar list of planned mods and I'm actually hoping for a better outcome.

In terms of gauges, you should also look at the UltraGauge. Cheaper and more gauges. There's also the bluetooth versions to look at.

Another mod to look at would be to install manual hubs. Not sure if they're available for that generation, but if you can get them you should be able to gain at least 1 or 2 MPG.

Another thing to look at is to get LRR tires for summer. I'm sure you need the heavy treads in winter being in Colorado, but at least in the summer you can take advantage of better tires.

Are you on any 4Runner forums?

Keep us posted with what happens!

I'll second on that. Even with the front-drive disengaged, the differential causes some drag.

how plausible is it that a kammback can be made for a 4Runner??

Our 03 Sport V8 would get 23 mpg with no mods if we kept the speed under 60 mph. I had big Michelin touring tires and had them at 10% below max. That was it. My old Tundra only got 16 mpg. I don't know if the final drive is different on the 4L six but I'd say pumping the tires up at moderate speeds should get you close.

It is very plausible, however the length of the kammback is 100% additional length on the back of the 4Runner. (Unlike a pickup truck, where a sloping shell can be put on the back with no length penalty.) If you wanted to make a kammback for a 4Runner, I would look at the back end of an FJ Cruiser, which appears to have several feet worth of gentle taper on the top and sides. You would want to make an extension that basically looked like that. You would probably want to attach it to the hatch so that it would lift up and away when opened.

It already is a Kamm-back.

You can probably get to 25mpg with hypermiling; but the skirts and wheel disks are still a good idea.

The flat bottom could extend from a diverter in front to a diffuser in back.

Good catch freebeard, but I don't know how useful a Kamm-back with no taper is...

SUV Kammback
 

This Kammback boat-tailing provided a 26% drag reduction on this General Motors SUV model.So roughly a 13% mpg improvement.More if driven fast.
http://i1271.photobucket.com/albums/...ntitled2_9.jpg

Here and I was trying to make the case that a Kamm-back converts a notchback into a squareback. Did GM call that a Kamm-back?

That model sure looks like an Ecomodder Metro.

did GM call
 

Actually,it was done as part of a Masters Thesis over in Europe.They identified the model as of a GM suv.Nothing more specific.

It appears the consensus is curved taper on three sides and a flat angle against the ground plane.

They even provide a line at 1/3rd length to suggest a livable truncation.