Toyota Tacoma

[Varu]

Hi all,

I thought I would share with you all the results of my driving experiments from some time ago in which I tried driving slow to increase fuel efficiency.

The average fuel efficiency of my 4-cylinder Tacoma is about 25 mpg. Not that great.

Some time ago I had occasion to drive for hours on end, with only about 100 pounds payload plus myself, and decided to make an experiment of driving slowly to reduce drag.

By driving on the highway at 50 mpg, I was able to get 33.7 mpg.

By driving on the highway at 55 mpg, I got 28.4 mpg.

And then some time before that I was aggressively using hypermiling techniques, coasting every chance I could and turning off the engine at traffic lights, and somehow I got 32 mpg.

I haven't made any modifications to the vehicle, except I should mention that I have a cap on the back of my truck that's slightly aerodynamic but by no means like a downward slant. It is a 'wedge' cap that rising 6 inches above cab.

The downward slant type of cap is what I'd like to get, if only I could find a manufacturer.

Enjoy...

[BamZipPow]

Auto or manual transmission? Regular cab or extended cab?

As far as an aerodynamic/wedge cap...yer gonna have to build one yerself.

[Varu]

It's manual transmission short cab.

[ShadeTreeMech]

that is one big advantage of not having an auto; being able to lug it in high gear. My autos would try to downshift constantly if I don't keep the speed high enough.

I think your aerodynamic cap would help tremendously. Here's a couple links

aero truck project begins

Truck Aero, Bed cover DIY tonneau?

Silverado aerocap build thread

[Varu]

Originally Posted by ShadeTreeMech

I think your aerodynamic cap would help tremendously.[/URL]

I need to replace my current cap so I'm going to see whether a cap manufacturer can make a custom, down-sloped wedge shape. Crossing my fingers...

[bestclimb]

A frame at the front of the bed matching the shape of the cab. Attach points for a tarp around the frame and edge of the bed. Get a tarp the length of bed and length of frame. cut the tarp to fit and hem with good contact cement and install grommets lash down tight.

[BamZipPow]

Originally Posted by Varu

I need to replace my current cap so I'm going to see whether a cap manufacturer can make a custom, down-sloped wedge shape. Crossing my fingers...

I'm sure they'll make you a custom one...fer like 3 or 4 times more than a standard one. I'd guess around $3000 to $4000!

I guess it wouldn't hurt to ask though...

Do you need security fer yer cap? Have you thought of just making an aero cap just fer aerodynamic testing, first?

A low cost solution would be to use some R-Matte 3 insulation board. It's pretty lightweight and easy to cut. You could tape the joints to keep it together. Make sure you fasten it to the bed securely before making any attempt fer aero testing. The key would be to design the angles and pieces before you start cutting up the boards. They come in ½" and ¾" thickness with 4' x 8' sheets and longer. You can find them at Home Depot fer about $10-$15 fer a ¾" x 4' x 8' sheet. I play with the ¾" thick stuff at the moment.

[redline5th]

That's great gas mileage on the ol' taco! Hopefully you enjoy building things, cause you'll have to for aerodynamic mods.

Good luck and keep us up to date!

[taco]

what year ? 2wd or 4x4?

[Varu]

Originally Posted by redline5th

That's great gas mileage on the ol' taco! Hopefully you enjoy building things, cause you'll have to for aerodynamic mods.

I do enjoy building things with wood but I hope I won't have to. I'd definitely refuse to mess with fiberglass because of health concerns.

But for now, I contacted the company that makes the aluminum caps for one of the major manufacturers for a quote...