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

AMSOIL is the premier manufacturer of synthetic oils, gear lubes, filters, diesel products, gasoline additives, etc. Their catalog is free: AMSOIL - Synthetic Oil, Motor and Engine Oil, Lubricants, Air Filters, Oil Filters and Greases. The oil that I run only needs to be changed every 25,000 miles or 1 year, whichever comes first. Their air filter is high efficiency (better air flow) and can be cleaned over and over. AMSOIL has been proven at the race track and on the street for several decades. It is better for your vehicle (including motorcycles) and you will save money to boot.

P.S. AMSOIL is NOT expensive. You can buy a one year discount card for $20. It is cheaper to use AMSOIL than to get your oil changed every 5,000 miles at the local Firestone. Get a catalog and check it out yourself.

Feel like putting together a critical summary of Royal Purple's efficiency claims? Most of it is "on road" comparisons which we can discount straight off the bat. I had a quick look at one of the two university studies that compared RP to dino oil, and they weren't even comparing the same viscosity in the dyno tests.

Honestly, that post may have come out wrong - I've only used it once, personally, and I never specifically tested it, although I did notice a MPG (not specifically miles per gallon, but more like gallons per trip) improvement in my old Jeep with it, and it SEEMED to have more power/torque as well. (1979 J20 4x4, 360CI V8, 3 speed manual)

I used the engine oil, trans oil, and rear diff oil all at the same time, like they suggest.

I'm sure part of those claims are eaten by the idea that changing all those fluids would give you a gain anyway, but it seemed to work for me. Also, none of those fluids have been changed since then, and the engine oil is still purple-ish, almost 3 years later. (It's a mountain use truck, never sees the road, but it gets BEAT ON... in fact, it's the only 8 cylinder I've redlined religiously, and it never sees 3rd, seldom sees 2nd gear, with 200k and no problems thus far.)

I'm sure their claims are probably somewhat bogus, but I can't dispute that it's a good product. You'd have to test it personally to see what I see.

3 years and oil is still good, that says something to me.