Aero Mods for my Nissan Frontier pickup - help!
 

I need a truck for my business that can haul big loads, tow a trailer and drive off-road in variable conditions. So I chose a Nissan Frontier V6 4x4 as the best value among small trucks that could do most/all of what I wanted.

A good truck, but not the most fuel efficient EPA mileage is 15/19, but with careful driving I get ~21/22. Still I would like to do better and I am looking to some aerodynamic improvements to do this. So far I have had the local glass shop cut some 17" plexiglass circles for me to act as wheel covers since I couldn't find anything else that would work in that size. I also had them cut out some elipses to cover the fog lamp holes on the front bumper.

The next easy thing to do would be a partial grill block. I think that blocking the lower portion of the grill in the area around the license plate is the best idea. I can get some plexiglass cut to shape, I just need to figure out how to mount it... probably some l-brackets will do. Alternatively, a single piece from headlight to headlight would do. I presume that blocking both portions of the grill would be overkill.

I think I want to try rear wheel skirts (which is photoshopped in the photo below). Not only should this increase MPGs, but it will also give me more area on which to apply the logo to my truck. I have a feeling anything I construct is going to turn out terrible, so does anyone have any recommendations as to where I would go to get one built? Would an auto body shop be able to make this for me in fiberglass? And how can it be securely attached to the truck so that it will still be relatively easy to remove when/if we have to change a tire? Are there any practical concerns with rear wheel skirts, especially for a vehicle that will be driven off-road?

The last (and probably most expensive) aero mod I am thinking of is a skid plate and belly pan. This mod has the added benefit of making the truck more durable for off-road use. I'm not sure at all where to go for this metal work, and if I do find a shop that does this kind of work, will they be willing/able to do a belly pan that focuses more on efficiency and less on toughness? For example, could the skid plate be big and thick for durability while the majority of the belly pan is thinner, and there mostly for the aerodynamics? Also, trucks with skid plates usually have big brush/grill guards on the front, which I don't think would help the aerodynamics much. In fact, it would probably hurt the aerodynamics more than a belly pan would help. Still, I wonder if some shop out there would be able to integrate something practice and durable that would also maintain aerodynamics.

So, does anyone have any experience or thoughts about this?

For the block it makes more sense to block the top. That way air hitting the block will transition smoothly to the top of the hood. If you block the bottom, the air will go up and hit the unblocked part and spill back out, like a parachute. A higher mounted block could also act as a ram I think, pushing air into the radiator.

I want to get a similar full belly pan made for my XJ. The normal material they use for skids is 3/16" steel, which is really heavy. I'm thinking 1/8" with dimple die holes for rigidity, covered underneath with HDPE, would be strong and light, allowing you to have a huge aerodynamic belly pan/skid. For all I know 1/16" could even be strong enough.

Aluminum might also work

I thought I heard something about 5mm of Al doing the trick, and that would be a LOT lighter than the steel, but once you dent it, you'd have to replace the whole panel to repair it... I would think.

Thanks for the thought on the grill cover. I don't think either would be too hard to do.

Too bad you needed to buy a new 2009 Frontier.

There are tons of older truck choices that would have gotten better mpg and you would have saved money.


That being said you seem like youre willing to pay a shop for pro aero mods
so a fitted aluminum belly pan would be a winning choice

after that, id look into an aero bed to cover the back

for grill blocks you could have a shop make custom fiberglass inserts to block the holes
that way its removable so you can return to stock

I probably should have mentioned that I am getting a cap for the back, which I expect will be on about 1/3 of the time. Really, I hall a lot of large things in the truck so a permanent cover would get in the way... of course I guess I'll find out how easy it is to remove the cap when I need to... but the cap should improve the aerodynamics a bit, right? I plan on getting one of those "AeroCaps" for my truck as soon as/if they become available.

The plexiglass grill block I have in mind will be easy to remove. It will be held in place via 3M dual lock. If the truck ever starts to overheat I should be able to pull over and take it off in seconds.

Go on Nissan Frontier / Navara Forum and buy a used set of Nismo skidplates cheap from someone who took them off for Shrockworks skidplates. They are pretty light weight, but will still protect you offroad. They have some holes in them (i guess to reduce weight) which would mess with aero, but you could just cover the holes with packing tape.

I'd also throw some chloroplast under the truck to cover the spare tire area all the way to the rear bumper.

The side mirrors fold in, and leave a nice teardrop shaped front profile, so keep them folded in when not needed.

I put a grill block on mine, and didn't see any FE improvements, but I only covered the side opening on the top grill, I think you could cover the whole top grill and see some gains with no worries of overheating, the radiator is mounted real low, so it gets plenty of air from the lower opening.

Also, some guys on clubfrontier.org saw gains from replacing the clutch driven fan with an electric unit.



Keep working on your hypermiling skills to. I drive a Nismo with ~300lbs of offroad armor, 5 1/2" of lift and 34" mud tires and I can get 22mpg on the highway, up from 16-17mpg before hypermiling. And I don't even pulse&glide, I just do the basics, and neutral coast/engine on, as much as possible.

I guess it would be best if you opt for the light weight skidplates.. And good luck on the plexiglass grill. These nissan frontier parts would surely be the good choice.