Proposed modification for SUVs
 

I'm a new member and am BLOWN AWAY that such a forum exists. I drive a 2002 Toyota Highlander 4WD V6. The 2 modifications that I have made is adding a ScanGuageII, which helps me drive economically, and using AMSOIL. The rear end of my SUV is similar to that of 18-wheeler, i.e., a square block. You may have noticed that some 'big-rigs' have added a plastic 'bubble' to the rear of their trucks, so that the air can flow smoothly rather than create turbulance. Their bubble is on a hinge so that it swings out of the way and the 2 doors can be easily opened. If this didn't help mileage, I don't think the trucking companies would be spending money on it. Question #1 - does anyone have data on their savings? My plan is to go to a plastic fabricator and have a similar bubble made out of clear plastic, and have it fasten to the hatchback on 4 slots/bolts that can be tightened down. I hope the weight isn't too much, but I can always beef-up the hydraulics lifts for the hatchback. Your feedback would be greatly appreciated.

Search this forum - keyword: Kamm or Kammback

bubble
 

Buddy,I think your on the right track.Over the Turkey-Day holiday,I brought back a rear hatch off my friend's Highlander(it was damaged in a collision and replaced) to help fashion exactly what you're talking about.He has the 4-cyl version,2WD,and is getting 28-mpg on HWY.We calculated that a 30-inch extension (measured from hatch surface,not rear of bumper) will push MPG to 32.0.------------------------- These "boat-tails" have improved mpg for my VW bus,CRX,and T-100.------------------------ I would caution you about Plexiglas ( I've never worked with Lexan).If it fractures it will come apart on you.There is no fiber matrix to it and it has zero strength in tension once it begins to fail.You might consider a more robust super-structure which can stand up to pot-holes,jarring,vibration,etc.,and add a Plex or Lexan window to that.------------------------ Also,if you are going to swing it from above,be careful to examine any interference do to the hinge geometry,which might occur at the roof/hatch intersection when your proposed extension is attached and fully open.

Thanks for the info Aerohead. I'm just a newbie on this project of getting increased mpg, but am looking forward to doing more in 2009.

IN addition to Kammbacks and boattails, you could look up grille-blocks, and several other aero-mods. You can also look into driving techniques as a means to increase efficiency, and there are several topics on ways to change your driving habits.

Another thing to look up, with tonnes of good info, are the build threads, specifically basjoos' thread on the Aero-Civic.

welcome to EM!

What do you mean by using amsoil?

Amsoil is a brand of oil, expensive and also quite well thought of, in many circles as a gift from heaven.

Royal Purple is also very expensive, and very effective... only $100 oil change I've seen to date. (including lube service, etc.)

But if you run normal oil, dyno your car, then run Royal Purple on the Dyno, it's guaranteed to show HP and Tq improvements due to less frictional losses... that's gotta say something for efficiency too.

Skirts!

The grass kind!




Sorry. :P