Full length skid plate - mpg

[RegularGuy]

I've been considering fabricating additional bolt on skid plates for the underside of my fx4 lvl2 in hopes of not only better mpg, but also some additional protection on the trails. Plates aren't too uncommon, did anyone see a mileage improvement or did the added weight negate the aero benefit on their lifted truck?

Has anyone done aero mods to their truck? What worked?

Additional plans for potential fuel savings include: switching to 245/75r16 tires, (Just changing from the 31x10.50r15 BF Goodrich T/A to a set of 265/70r16 Michelin LTX gained me 1-2 mpg) switching to electric radiator fans while also increasing rad thickness, and potentially changing oil weights (I need to do some research in the manual on that last one)

 

[adsm08]

DO NOT CHANGE OIL WEIGHT. Ford tried to run the 4.0 SOHC on 5-20 for a few years. That ended badly. The 4.0 SOHC was specifically exempted in the TSB that changed all of Ford's other engines to 5W-20.

Swapping a Mustang front clip onto the truck may help with aerodynamics. Even the late Rangers were basically just bricks.

 

[RonD]

An air dam under front bumper would be better, but also would get damaged when off-roading, lol

Point of Aerodynamics is to get air to flow around a vehicle with the least resistance, when you push the air down then its flow is below underside of vehicle reducing drag.
Full underside shields might help but you still have the axles, that would be the biggest drag in 4x4 trucks, so deflecting the air down at the front of the vehicle would be better

Full underside shields would be good for off-roading, but yes the added weight would lower MPG

 

[sgtsandman]

I'm with RonD on his comment. If you go with aluminum, the smoothing of the underside of the truck might negate the added weight of the plates but if you go with steel because it's cheaper, any mpg gains you might see will be negated by the added weight.

On the plus side, the plates being mounted on the bottom of the truck will help lower the center of gravity.

One thing to consider, if you decide to pull the trigger, make sure the plates are maintenance friendly. Have removable sections where the oil pan and filter is, access for the transmission, and to have access to the transfer case. One thing they did with the skid plates on the 2019, is the oil pan section has slots where the front skid plate and the engine skid plate meet. That way, you can just loosen the bolts where the plates overlap and slide the engine plate out. You might want to do the same with that and the following sections moving aft for the transmission and the transfer case.

 

[Shran]

I have full skid plates on my Explorer. One in front of the trans cross member and one behind it that is about 4' long. Probably adds about 100lbs to the truck. I have not seen any changes to my fuel mileage, although it's awful to begin with, mid teens on the highway at best. I'd be shocked if you see a significant difference.

Before I did anything to it I would see over 20mpg on the highway all the time... I think my front bumper and roof rack changed things the most.

 

[HenryMac]

Seen this?

XCOR’s ‘Trunnel’ is Built Ford Tough + Stratolaunch Boss Flies to ULA

 

[MikeG]

That is as ugly as a mud fence....

 

[Curious Hound]

That is as ugly as a mud fence....

No. You just complimented it.

 

[Uncle Gump]

I went from 19 MPG to 17 MPG real quick. Just add bumpers and 32 inch tires.

I wouldn't have it any other way though... just the price you pay.

 

[Curious Hound]

I don't bother with mpg on the Ranger. Down to 1/4 tank? Fill it up.
On the way out for a day of off-roading? Fill it up. Might not be driving it for a while? Fill it up. Looking for something to do in it? Go to the gas station and fill it up. Happy? Fill it up. Depressed? Fill it up. Think it might snow tonight? Fill it up.

 

[sgtsandman]

I only pay attention to the mpg for indicators of impending problems. Unexpected fuel mileage changes can indicate a looming problem. It let me know when the driver’s side cat was starting to fail. The mpg got real good all of a sudden for a couple tanks and then CEL.

 

[Uncle Gump]

Gonna do a Popeyes Chicken run... that makes me Happy! I've been thinking about filling it up.... so I will just fill it up!

 

[RegularGuy]

Most of all, I'm just trying to improve my range without adding fuel. As it stands, I can get about 260 miles for a tank which to me, is less than ideal. Light comes on after 16.5 gallons or so (15-17 mpg depending on driving mix). I'd feel a lot more comfortable doing the bi annual trip to Kelowna, BC (around 300 miles) if I was reliably achieving a longer range. (Fuel availability can be sketchy during the winter for 2/3rds of the way)....

I'm not looking for miracles, getting the mpg closer to the 2wd figures would be more than enough for me (rating of 17 combined versus 15)

On a side note, anyone know if there's a difference in rolling resistance between LT tires and "regular" tires assuming it's the same tread?

 

[Roert42]

I'll say, before my Supercharger was installed, I averaged between 15/17mpg with my 2WD.

I get about 20 MPG now, run 93octane with the stock tune, could probably be a bit higher if I had the truck tuned too. Fuel cost is higher, so it adverages out the $ per Mile, but I do get better range.

 

[RegularGuy]

Do tell more...... The way I understood it, the sohc knocked from the factory on 87. Thus, I wouldn't expect super/turbo charging to pay off without changing internals. Additionally, without a tune I'd anticipate the engine running lean