Light Ecomodding: spats, active grille shutters, underbody pans

Try it sometime. That's not my personal experience with my Tacoma. I'll occasionally hyper-mile on long trips if I have the time.

 

Nothing fancy. Just the 2wd V6 with stock SR5 tires in my profile picture. But I’m pretty good at looking ahead and coasting, changing lanes, and accelerating in a way that is really fuel efficient.

Agreed. First, it’s a fun project for me. I’m looking to learn as I go. And I’m not wanting to spend a thousand bucks on this either. The spats could be almost free, and @skyking3 did his underbelly pan with a $100 sheet of aluminum, which is not armor (and I don’t need armor). The grille shutters are mostly plastic except the small motor that’s usually wedged between the louvres, but I’d need to install some sensors to make sure it’s safe—the grille shutters mod is the most complex and potentially sketchiest of the three ideas.

Lighter wheels would help. Does anyone want to donate their light new 2020 Pro wheels in the name of science? ;-)

 

Yeah, I’m trying to not ditch the seats because my kids sit there! I’m also figuring all three things might not work as intended. Skyking3 saw something on the order of 1mpg gain with his underbelly pan, I think, but we’d have to see if I could match that. Is there a reason you are suspicious about grille shutters? Lots of cars have them to eke out a few more tenths at highway speeds. Most of my normal commute is 50/50 city/hwy, so I think I could use the grille shutters at least on that segment if it didn’t screw with the operating temperatures too much.

 

Honestly if it would gain anything Toyota would have done it already. This truck does not have the shape to fix drag with a grille shutter.
Believe me, Toyota benefits the better mpgs they get. However, they also have to sell the damn thing so they compromise.

 

@Malvolio wouldn't you take a hit in the MPGs with bigger tires?

 

He would but not smaller, lighter and harder summer tread tires. Those would be optimal for mpg.

 

I think so, yes, so I’m not really worrying about the tires until my original 245/175R16 Firestone Destinations wear out.

 

I'm actually trying to figure out what tires to move to myself. I'd like to keep my MPGs up and don't really have a need for anything larger. Stock hanooks on 16s atm

 

gotta ditch those step

 

Get rid of the side steps and roof rack and *poof* there is your extra mpg. Those two items are pure efficiency loss, both in weight and aerodynamic drag. If you are looking to learn then delete those things.... but wait... they look cool right? So now you are faced with what engineers are faced with every day... function vs. form. Good luck I'm out. You are not serious if you have these things hanging on your truck.

 

Actually, Toyota has put somewhat equivalent belly pans on all of the cars and SUVs that they sell for improved aerodynamics to improve MPGs. Only the Tacoma and Tundra trucks do not have them because so many owners take them off road where it would not be practical. While the basic shape of these trucks are not aerodynamic Toyota has done what they could in small ways to improve it such as adding small vortex generators in some places. The greatest area in need of improvement on our trucks is the under side. The following are a couple of quotes from my previous posts.

Quote:

Almost 2 months ago I upgraded to the TRD 17 inch wheels in preparation for the Wilwood big brake kit. With slightly larger tires my MPG took a small hit so I started looking for ways to get that back. For some background I earned my commercial pilot license in 1972 but since the airlines were not hiring then I went to the Navy flight school and spent 20 years flying in the Navy. After retiring from that I changed careers but never forgot the aerodynamics that I learned. In an aeronautical engineering class I took in college I had to design and build 2 aircraft wings. One was for high speed and low drag and the other was for low speed and high lift. We had to put sensors everywhere and put them in the wind tunnel.
On the upper part of the truck the only thing that may make a small improvement is a tonneau cover which I already have. Therefore, I looked under the truck to make some improvement. I use the truck for towing once a year and hauling several times a year so I do not need skid plates for off roading. For the last 2 weeks I have been designing and building an under body pan to improve the aerodynamics. I will be driving a couple hundred miles in the next few days so I should get an idea of any improvement. I would like to put my truck in a wind tunnel but the closest one to me is at Florida State University and they want $15000 to use their facilities. That is not going to happen!

End quote.

Another quote with some of my testing results:

The trip information is from a trip that I have made around 25 times in the last 2 years. I was averaging 24-25+ MPG before the new wheels and tires but it dropped to 22-23 MPG after. You can see that my MPG on this trip was 25.5 MPG. I will be making this trip another 10 times in the next few months to get a more accurate average but I am very pleased with the preliminary results. This trip is almost 90% highway on I-95 in Florida which is about as flat as you can get. I usually drive with the flow of traffic in the middle lane which is 75-80 MPH. I do not expect the city driving MPG to be very different because the effect of drag is much less. The following results are from a trip that I drive once a week.

25.5MPG
25.1MPG
26.1MPG
23.9MPG (huge headwinds)
25.9MPG
24.7MPG
The next 2 results were taken after I removed the pan since I was taking it to the dealer for service.
24.1MPG(no need for AC)
23.6MPG(AC needed)
The average with the pan is 25.2MPG and the average without is 23.85. the pictures below were taken with the pan on.

 

Agreed that they can’t be helping things. But I’m not in a place to pull them off based on current use and accessibility needs. We added the rack because we needed one, so I picked what seemed to be the most aero option. As for the other stuff...

 

Nice work. Curious what model / size tires are on the new TRD 17" wheels? I'd like to go up in tire size slightly (currently still running the oem lightweight 245/75r16s).

Thank you for your service.. I imagine you flew some sweet hardware!! I'm a private pilot and fly a fairly slick (low drag) experimental that requires decent energy control. I use similar energy management planning when playing the hyper-mile game in the Tacoma.

Would you consider adding OVTune's turbo kit if it can increase mileage?

[Before anyone jumps in claiming the financial investment doesn't add up.. I'm not playing the game for costs.]

OVTune's early claims are that boost will come in low (before the 1700 rpm sweet spot for highway miles.) If so the added torque down low might allow us to stay out of downshifts on the grades. I'm just guessing as the entry boost will require slightly more fuel BUT the offset/reduction of downshifts may more than make up for it for my typical terrain. Perhaps down in FL you don't have an issue with grades/inclines but here in VA it can kick mileage square in the groin.

I imagine Tacoma owners out near the Rockies hear our claimed numbers and think we're blowin' smoke.

 

Oh snap, here we go

 

What's the savings for a prius?

 

Elon musk doesn't give 2 shits about how his Lego truck looks. Pre sales are out the roof. It's def not for me. But I see the appeal

 

It would be about $4,800 more fuel dollars out of my pocket if my family had driven a second 24mpg Tacoma instead of the Prius plug-in we put 41,000 CA miles on in the last two years. Wait for the new hybrid Tundra (Tundrius?) And I think we all can guess what comes next.

 

Don't get me wrong... I'm all for efficiency. On my Tundra I get 18 mpg highway usually. That's good for that truck. Unfortunately I am usually towing or hauling so efficiency goes out the door.
But, I run 37 psi in tires, no aggressive tread, no aftermarket add ons to suck efficiency, tool kit is minimal, i drive like an adult, etc.

To the other posters... planes and vehicles have a lot in common but the main differentiator is rolling resistance. You can gain more by inflating your tires (not beyond max on side of tire but close) than you can by reducing drag. Add both and you are golden. However... weight is a penalty more on the ground because of ground pressure = more rolling resistance.

 

I agree with you, summer i usually run 35-37 psi, but winter months i prefer to air down a bit i feel i get better traction in the wet, snowy climates.

 

First round of orders are the fanatics. Let's see how many cough up $70K for the truck. Toyota markets to the masses.