UPDATE:

So, over the past months I have added larger tires (the stock tires give the H3 no justice) and added a scanguage e, and most recently t Volant PowerCore CAI. Before any upgrade (bliss) I thought I was doing ok, I was averaging about 17. I added the scanguage to give me some idea as to how I was driving. That little guage more than anything, keeps you conscious of your MPG and teaches you how to take advantage of every gallon.

In April I purchased some Duratrac AT (305/70/16), I got them for a good deal and wanted a larger tire. i knew my MPG would drop. This upgrade cost me at about 2MPG and I was reminded every time i looked at the scanguage... my average dropped to 15.5MPG. The truck was noticeably more sluggish (especially around town), and as much as I loved the look of my truck, I hated the loss in on-road response (remember I am mostly on the highway) and mpg.

At the end of August I did extensive research, and chose the Volant Powercore Cold Air Intake and it has been the best investment so far. My MPG boosted to over 20 average and my best so far has been 25mpg! Again, I drive 90% highway, and sometimes baby my H3 to see the better fuel efficiency. I have done the fill-up, reset odometer, drive, fill-up sequence as well and I have been getting about 20+mpg.

When my "Low Fuel" light pops on, I expect to report it here shortly... and THEN return to my normal driving habits which should put me back at 19-20 mpg. I don't have a roof rack or crossbars, most of my driving is highway, and the scanguage at minimum keeps me aware of "how" i drive.

FUTURE: I think my next tire will be skinnier but taller Toyo 295/75/16 AT. And I plan on getting an e-fan and Performance tune next year... THEN I'M DONE! It feels pretty great to have the vehicle you want and tune it to your desires and thats what I have in my H3. Thanks for the dialogue folks.

 

..after a bit more "testing"... I am comfortable stating that 19 mpg is my average with my current setup. I think by the next winter i'm going with 285/75/18 Toyo Open Country AT2 tires and a 1" body lift. I will surely crank to 23.5.
2014 upgrades coming... new wheels and tires, body lift, aftermarket stereo, off road OEM lights (SOMEBODY HELP ME FIND THESE!!!)

 

I have a stock Base H3 with brand new 315/75/16 Fierce Attitudes, a very aggressive tire. After a couple of tankfuls, I'm getting 12-13 mpg. Ugggg...

 

my only reference is two stock i5 h3.
one, with stock 265's did 20 mpg on a trip.
two, stock 285's on the same trip never tops 18 mpg


in winter I don't bother checking, I don't want to know.


fwiw, I once took a gas can with me and continued driving after getting the warning low gas.
I went 50 miles and gave up, filled up. I guess its more than 50 on mt.

 

Hey guys, i posted earlier and forgot to add my mpg. I have an 06 lux and the first few months i got 19-21 mpg and not anymore. I think i get 16-19 depending on where I drive. I am in winter which makes it worse. All I have done is tires and brakes and tb clean and maf. I am getting my shocks soon bilstein 5100 ( oh yea i can use them with stock ride height right) and a new exhaust manifold, typical cracked crap and I assume the magnaflow is better than another stock one? And and a bunch more stuff. the scangauge is a good idea i think...

 

the scan gage is good for a lot of things but with all the data available at obd2 I don't see why you need to tell it how much gas you put in EVERYTIME!. I played for awhile and stashed mine somewhere.
I had old cars with trip computers b4 obd2 and you told them nothing,they were dead on.
I really had hope for sg2,alas..


oh, did the 06 3.5 get more mpg on the sticker?

 

So the scan gauge doesn't tell you current mpg? Or does it? I assumed it did just like the ones from the factory do which I think they shoulda put in our rigs. About the 06 having better mileage on the sticker I don't know. I just bought mine a year and a half ago. But I have no doubt someone else here probably knows and will prob fill ya in. I love my 3 but shoulda bought from a dealer... private sale and got a good deal I think. But no warranty and have had to put a couple grand in it and gonna dump another 1500-2000 here in another week or so just in parts, good thing I am on here I guess so I can figure stuff out and turn my own wrenches, this site has saved me at least a couple grand in labor alone.

 

I quit using mine since it required so much careful attention. you need to tell it exactly how much gas you add, and never miss!!. otherwise it is very useful. read about it . im sure you can dl the instructions.

 

yea....

 

I drive mostly on the highway. Per tank I'm around 360-375 miles per fill up. I only really pay attention when I travel a few miles. I don't wanna know how bad it might be driving around town to go to Walmart and McDonald's.