Will someone please help me regain my 17-22 MPG back?

[Doozi]

Unless you've thrown a code for failed O2 sensors, I wouldn't touch them.

When the mileage crashed on my Gen3, I ran a scan and found something like "O2 sensor slow to respond" before it tripped the CEL.

The OP should definitely run a scan before dismissing the O2 sensors.

That was my experience on a Gen3... I don't know if the Gen4 would behave the same or not.

~Doozi

 

[chayos00]

Great question- thanks for posting.
I have a similar problem. Did full maintenance but mpg SUCK! :beer:
O2 sensor? Thats new to me to chnage them for possibly better mpg. I've had it happen before on my 94 Ranger. Any links to "how to" on the forums? Is it easy to do on my driveway?Should be, just look down your headers and you should be able to see them. Anyone have avg prices for new o2 sensors 2 of them as others stated.Checkout Autozone.com for prices.
If MAF is cleaned, still poor mpg could it need replacing?I swapped mine when it was just the o2 sensor, glad they took the part back.

Hi.:50cal::happens::surfer:

 

[Atlanta_man]

I wonder if the winter/summer gas deal still holds in places that require the use of 10% ethanol year round ?

Anybody ever try the 3oz / 10gal acetone in the 4Runner to boost mileage ?

 

[glock56534]

I definitely get lower gas mileage with the 10% ethanol gas. In my '05 SR5 V8 with 120k miles, I get roughly 19mpg on the highway with regular 85 octane gas and about 17-17.5 with 85 octane / 10% ethanol.

I'll second using the SeaFoam, that stuff is the bee's knees for all gasoline and diesel engines! Add some to your oil 800-1,000 miles before an oil change and add a bit to your gas tank each time and your engine will like working for you.

 

[V8Limited4wd]

I wonder if the winter/summer gas deal still holds in places that require the use of 10% ethanol year round ?

Anybody ever try the 3oz / 10gal acetone in the 4Runner to boost mileage ?

i have used acetone and it would boost my mpg about 1-2mpg. didn't want to worry about long term affects to the parts so i stopped using it. i have also used the lucas oil fuel treatment and it improved mpg and seemed to make the engine smoother and have a tiny bit more power. I wouldn't use it all the time so when I did when I filled up I would notice the difference.

 

[virulosity]

I get 19mpg with my v8 on 87 octane chevron (computer claims 22mpg). I replaced the plugs 10K miles ago (at 140k now) and the airfilter, but have never cleaned the MAF or reset the ECU.

I used to own a turbocharged subaru and I would notice significant changes in mpg by just changing the brand of gas I used. I used to repeatably get +2mpg using Mobil gas instead of shell or chevron (wierd I know). When I tried the Mobil in my T4R, it made the cabin smell bad exhaust fumes so I stopped using it. IMHO, trying different fuels is definitely worth exploring.

 

[Nuke]

One problem with getting a good grasp of your car's actual, average fuel mileage is the variance in % ethanol at each fill-up (in addition to the other dozen or so variables); even if it's from the same station. It's not uncommon for one load of fuel to be ethanol-free and the next load containing 10% ethanol or even higher, despite the tag at the pump.

Fuel mileage can only be determined over time. Variances in the fuel simply make it that much tougher to determine. You need multiple data points and that requires logging your mileage data; NOT looking at a display and reacting to the current and previous value.

 

[ronsta]

Hey OP, any changes to your MPGs? Which fix worked for ya?

 

[TOYLUVA]

exactly what the title says...im seriously getting tired of watching my MPGs fall everytime i drive it...my 01 camaro ss is getting better gas mileage then my 4runner..went from 397 miles per tank to 293 per tank...help please??

This may sound dumb but when I read your signature, I think you might need a bigger alternator. If you are running all them amps and lights at one time, your alternator might be giving your fan belt a little resistance. Check all the other stuff first but if that doesnt help, I would turn all the stuff off for a tank or two and see if there is any difference in mpg. shoudnt be enough to kill 5 or more mpgs but it might. just my thoughts. no scietific evidence behind this.