Improving MPG?

[EHNWI]

So it looks like a lot of us like to install things that kill the gas mileage, but are there any mods or anything that could improve it?

When I got the vehicle stock, I was getting around 23mpg. Not bad for a bigger vehicle. With the roof rack and BFGs, I'm now getting between 18-15 sometimes. Getting good MPG isn't a huge deal to me, but getting a little more out of each tank would be a pleasant surprise.

 

[BlackWorksInc]

Buy a Prius...

Now that we have the semi-joking response out of the way. You could regear the vehicle and that theoretically would help maybe return a couple MPGs, but realistically for the cost involved it'd take a lot of gas tanks to get that back.

The reality is that the more "Off-Road" your truck gets, the more MPG suffers because of weight, drag (in various forms, aerodynamic, tire tread & composition, ect), and over all physics. You could probably drive more conservatively (i.e. be a Prius driver and have people ready to murder you on a daily basis), but there isn't much hope otherwise, sounds like you're getting good MPG though 18mpg isn't bad for a modded truck.

Due to my driving habits I can get as low as 10-12mpg in the city, and maybe 17-ish on a good long road trip.

 

[HokieRunner]

Other than keeping your tire pressure where it should be and keeping mild driving habits, not really. Unless you really need the roof rack ALL the time, remove it when you aren't using it for a couple mpg improvement. Other than that, I defer back to the Prius suggestion

 

[EHNWI]

Other than keeping your tire pressure where it should be and keeping mild driving habits, not really. Unless you really need the roof rack ALL the time, remove it when you aren't using it for a couple mpg improvement. Other than that, I defer back to the Prius suggestion

Roof rack usually comes off during winter because of the hassle of clearing it of snow. I'd like to be able to pop it on and off easier, but it usually takes a little bit to get back on because I am so OCD about getting it perfectly center with the truck.

 

[HokieRunner]

I hear that. I loved the mileage I was getting with mine off but it's a hassle to take off every couple weeks.

Keep filters etc clean and you can do the hydrocarbon filter removal but that'll just give better throttle response as far as I know. Window down, AC off too haha

 

[4RunnerFan]

The tire pressure on my Limited's 18"ers is supposed to be 32psi, but for over four years I was driving at 36psi because for some reason I got it in my head that it was the same as my wife's vehicle (hers is 36psi). So I get new tires this past summer and the tire center fills them to 32psi. I didn't say anything because I figured I should check the vehicle tire and weight sticker inside the door first. Sure enough it said 32psi.

Can't feel any appreciable difference between then and now, except gas mileage has been down a tad, so guess what; I'm boosting the pressure back up to 36psi.

 

[WXman]

I experimented with the roof rails off and saw zero difference.

Keep the suspension stock and the wheels and tires stock. Keep the fluids changed regularly and filters clean. Keep weight out of the cargo area when not needed. And obey the speed limit at all times. Doing these things will get you really good mileage for a SUV of this size and weight. When stock, the 17 I was averaging was better than any 4x4 I've ever owned except the Liberty CRD and Wrangler 3.6L.

 

[boondoggle]

You could try lowering it.

 

[Martinjmpr]

In addition to the usual recommendations made above (maintenance, tire pressure, drive like grandma, etc ) I'll add a couple:

1. For around $70 you can get a gauge that will give you your "instant" MPG like the Ultra Gauge. For about double that you can get a Scangauge II that will not only monitor your MPG but will also give you transmission temperature (good to know especially if you tow a trailer like I do.) Having a gauge like that can help you "hypermile" because you get an instant feedback when you mash the accellerator and your instant MPG drops from 20 to 6. After a little practice you can get pretty good at maximizing your MPG this way. I run an Ultra-Gauge on my DD Mazda pickup (which has a manual tranny) and a Scangauge on my 4runner. As a plus, both gauges can be calibrated to give you precise readings (as opposed to the factory "computer" which is basically a useless decoration on your dashboard since it rarely gives correct information.)

I've been running an Ultra-Gauge (UG) since October 2010 and a Scangauge (SG) since February 2012 and like them both. Each has its pros and cons:

SG: Pros:
* has more options (like Transmission temp)
* can be installed in more places due to its smaller size and network cable input (it has inputs on the side or the back and all the buttons are on the front so it can be "flush mounted" almost anywhere)
* Adjustable colors to match your interior

Cons:

* Costs twice as much
* Not as easy to calibrate (you have to be driving to calibrate it, which I think is stupid and also dangerous.)
* Cannot be calibrated as finely (1mph increments only, no calibration for distance)
* Only displays 4 gauges, display can be hard to read (it's a very "old school" "80's" looking display.)

UG: Pros:

* Less expensive (around $70 last time I checked.)
* Easier to calibrate, can be calibrated much more accurately (and can be calibrated when stopped, which is easier and safer.)
* Larger, easier to read display
* Displays 6 gauges at a time vs. SG's 4

Cons:

* Won't display certain things (trans temp, to name one)
* Installation not as flexible because cable is permanently attached to device.
* Need to access rear of device in order to set/program/calibrate (buttons are on the back)
* Only display color is blue on a black surface (but it's pretty easy to read even in bright sunlight - I've never had a problem reading it.)

UltraGauge OBDII Scan tool & Information Center

As a plus, either one will read and reset any CEL's or trouble codes.

2. Another thing you can do, if you have the money and the storage space is to run a separate set of wheels and tires for Summer and Winter. Where I live in Colorado, we do most of our "off roading" in the summer months. By the time October rolls around, most of the trails are closed by snow. So in the summer I have a set of FJC steel wheels with BFG MTs on them in 255/75/17 - a big, meaty tire that's great for off roading, but not so great for gas mileage. This is no big deal for me since my 4runner is not my DD.0

Come winter, the BFG's come off and the stock 16" wheels with stock size tires go back on, tires are Cooper Discoverer M+S and they have the "extreme weather" winter rating, which means they're great on snow and ice. In April or May I'll switch back, even using the factory bottle jack switching all 4 tires typically takes less than an hour and a half.

 

[ebg18t]

Martin - do you remember your mpg difference when changing between your summer and winter setup?

 

[Martinjmpr]

Martin - do you remember your mpg difference when changing between your summer and winter setup?

For the exact same kind of driving, it's about 2 MPG, once I correct for distance (the bigger MTs register fewer miles on the odometer, which makes me think my MPG is going down, but actually it's not going down by that much.) However, I should point out that I use the 4runner differently in the winter and summer.

In Summer, I usually take one long camping trip by myself, so that's just me and the truck driving long distances (highway) and then doing several days of off-road driving in the desert. This is where I register my best MPG, BTW, I've hit over 22 and that's with the MTs.

The rest of the Summer, the primary use of the 4runner is to pull our Teardrop trailer when we go on camping trips. So my average MPG goes down, but it's hard to quantify just how much it's going down from the tires vs. how much it's going down from the trailer (which weighs ~1,000lb.) Also our destinations are often in the mountains with a lot of slow climbing which also kills MPG.

By contrast, in Winter, I primarily drive the 4runner around town on weekends or to work and back if there's snow or ice on the road, which means I'm in 4wd (unlocked center diff, usually) a lot of the time. So the fact that I'm going slower and using 4wd also eats up some of my MPG (not to mention winter-blend gas.)

Sorry for the non-answer, obviously the reason I switch tires has nothing to do with MPG. If my 4runner was my DD, then I'd have a better "baseline" but as of right now it's not. Having said that, better MPG from the smaller, lighter factory-sized tires is pretty much a no-brainer IMO.

 

[Nuke]

yeah, other than maintaining your vehicle (plugs, oil changes, tire pressure, yada-yada) there's not much you can do mod wise. The biggest culprit is your foot and hand-foot coordination. It still surprises me the # of people that not only race to the next traffic light or pile of stopped traffic up ahead but those that are obviously still under light acceleration when conditions ahead will require you to decelerate or stop anyway. I also know that my AC typically causes about a 1-2 MPG drop, minimum, between tankfuls.

Regarding tire pressure, it also surprises me to know how many people are unaware of the pressure-temperature laws and that a tire at 30 PSI at an ambient temperature of 80 degrees F will be at roughly 25 PSI when the ambient is 30 degrees. Rule of thumb is about 1 PSI change for every 10 degree change.