AeroTaco Concept
 

Well, for my first post on this forum I figured I'd jump in head first with an idea I've been toying around with for some time.

My good friend drives over a hundred miles on an average work day, moving from jobsites to scrap yards and back again. He currently drives a 2001 Toyota Tacoma 4x2 Manual pickup single cab, with the smaller engine. His mileage sucks, and me being the local mechanic to all my friends, have made various suggestions to improve his efficiency. Easy things like replacing the fuel filter, the spark plugs, the air filter, cleaning his MAF, checking tire pressure, ect. This has netted him about 3 - 4 MPG increase combined with the "new" driving habits I have taught him.

We have been discussing ways of further increasing his mileage and I've come up with some ideas. Obviously, the majority of efficiency loss on this vehicle is from the horrific aerodynamics. Some ideas for helping this have included a suspension drop to bring the vehicle down lower, along with various body modifications... from simple to rather complex.

The simple things, shaving antennii, badges, smooth hubcaps, mirrors and the like are self explanitory, but we have been thinking of some major projects like a tapered bed-cover (but he needs it to be able to open because, it is in fact a truck and he needs the bed, but never really fills the bed up past the edges), a front air dam, underbody panels, wheel spoilers, smoother the rear bumpers, and connecting the cab to the bed.

Some of this we have been thinking would be best done in fiberglass, namely the front bumper and the bed topper, but for the rest we have been thinking about ABS plastis or even vinyl for things like the cab to bed transition.

Here is my cheap attempt at a photoshop of the ideas we have been discussing.

http://i15.photobucket.com/albums/a3...I/AeroChad.jpg

I was wondering if anyone had any input on what sort of improvements we would gain from this. The vehicle MUST remain useful as a beast of burden:turtle:, so no wheel well covers as the truck will travel through construction sites.

-Cheers, Justin

Welcome to the site. I don't know if you seen this but it will help quantify some of the mods. Sound like a pretty good plan.

http://www.evworld.com/images/pknox_toyota.jpg

Granted the bed topper is not functional here but it would still give you the same benefits if your was.

Wow, thats like a white version of my photoshop! Perhaps even the rear-wheel cover they use would be usable for my friend...

That site mentions a 28% increase in fuel economy, while the design I've been thinking of could provide even better results due to the from air-dam.

We have been thinking of use a dis-used flat bed topper we have lying around and using that as a base to build our design on. This current topper is hinged and sprung so perhaps with some stronger springs this top could support itself and make loading simpler.


I believe what would attack plan will be is of course to do the easy cheap things first, chopping mirrors, smoothing transitions, while we work on the more laborious task of fitting under panels and the mega task of the bed topper. The goal is to make this all 100% removable, and also 100% permanent should we choose.

I think I have a lot of research to do, as far as all of this Drag Coefficient, Data Acquiring, and testing goes but I think this vehicle stands to benefit HEAVILY from the aeromodding and thusly pay for all the work done within a year of the installation.

Keep in mind that is improved gas mileage by 28 percent over the original highway mileage. If he's doing a lot of driving in the city from site to site it won't be that good. The best bang for the buck would be FE instrumentation IMO. Take a look at a Scan Gauge. Instant feed back will really help with the mileage.

http://www.scangauge.com/assets/grap...ctspage_1a.jpg

Sounds like a great project keep us updated. :turtle:

I would say his city driving is no more than 10% total. We'll take a look at the scan gauge, we were thinking of a physical fuel flow gauge, if such a thing exists.

If you're going to install a smooth underbody panelling, then you won't need the air dam. Air dams can only help FE by diverting air from an aerodynamically dirty underside. Otherwise they add drag by increasing the frontal area.

Well that makes the whole idea a lot simpler. Would it be a good idea to instead block off the radiator grill and lower grills?

I've had both grill openings on my 97 Ford F150 4X4 totally blocked off since last spring and haven't had any overheating, even when pulling a loaded stock trailer in 80F temps. The only cooling air flow is through the 1/2" gap that runs the width of the trunk between the top of the bumper and the front sheet metal. I made the grill block of black duct tape, so I can easily remove part of it in the event of overheating. Truck grill intakes are sized for the largest available engine option towing the heaviest loads under the hottest summer temps and so are massive overkill for 99% of your driving.

If you are going to block off that much frontal and lower air flow, you may look into something that will allow some flow out of the back of the hood. cheap racer trick is to add a couple of washers to the mounting brackets(between the hood and the pivots) so that the hot air gets pulled out of the back of the hood. There may be no need on the little 1.0L cars, but I would bet that things are really getting taxed on the larger vehicles. at the very least the under hood temps are getting so high that its going to cause the intake air temp to climb rather high, which will really be a negative hit on efficiency. Even with a fresh air intake added, the heat soak in the intake manifold will be taxing.

I wouldn't think a Ford F150 would be considered a "little car". Actually, the air would be entering through the raised back of a hood. The base of the windshield is a point of high pressure with most cars (which is why they place the air vent intakes there). So raising the back of the hood allows additional air to enter to join the air entering through the grill inlets and eventually exiting out the bottom of the engine compartment to add to the air turbulence underneath most cars.