What mods have you put on it?

Winter also drops mpg hugely.... with the warming up of the vehicle... fast idle at startup... winter blend gas... it all adds up

 

These:

A set of 33 in mud terrain tires (I'll replace them for a 33-in Toyo Open Country AT III),
TRD performance air intake,
AFE throttle body spacer,
AFE 3 in exhaust system.

Also, it's not too cold here, around 40 F at the lowest.

 

Gas mileage shock w the FJ was a real thing for me. Ive owned it a bit over 2 months now and recently put Toyo AT3's on 285 70 17 and 2.5 inch lift. No bofy armor.

I drove 350 miles to Buffalo last Thursday and my gas light came on after traveling 190 miles! I was like...WTF!

After all the reading I did over the weekend i realized there's little i could do. Apparently i sacrificed some MPG's for mods.

I decided today ( as we speak) to test out changing my driving a bit. I'm literally on my way back from Buffalo now. Same 350 mile trip and made one simple change. Set the cruise a tick under 70, kept the rpm's just below 2k and my check engine light didnt come until 248!! That's almost 4 mpg's just from changing my cruising rate from 75 to 69.

It's not a home run by any meand but I'm definitely happy to know that my driving habits can improve my mileage. I took a pic today the second my light came on, showing my trip mileage.

 

I was hard on my gas pedal, with 16's & it was horrible gas mileage..200+/- tank! When gas was $4+ Gal!!!
But! You they are correct on the gearing/mods.
Good luck

 

How hard are you on the accelerator?
What speed are you driving at?

 

How hard are you on the accelerator?
What speed are you driving at?

Not hard....highway driving. Cruise control at 69 acoording to waze. Truly made a big difference.

Do I like driving at 69......no, not really. But I like it more then watching my fuel needle fall like a lead weight.

Just nice ( for me ) to know that when i feel like it I can improve my mileage.

 

Any advice regarding my plan to regear my FJ with a 3.91 or 4.56 gear set that I was told?

You can take a look at this chart and calculator, I got the infor from there.

Gear Ratio Calculator

Easy to use gear ratio calculator. Use our gear ratio calculator to find the correct gear ratio to run when changing tire sizes to keep your stock gearing.

tiresize.com

 

That chart is way off. I'd look at a gear ratio tire size chart such as this one to keep said vehicle in the stock power band:

 

It's a brick moving through air. Enough said.

 

LOL Agreed. Is there something else to improve that?

 

just get a bigger gas tank..

One mod and you can stretch the time between fill ups...

Looong range..

 

just get a bigger gas tank..

One mod and you can stretch the time between fill ups...

Looong range..

Good idea. I will do that but the main point for me is how to save money on gas.

 

Buy yourself a scan gauge and setup to view instant fuel consumption then learn to keep that number as high as you can while driving. did that to the Wifes FJ she went from 12.7 to 17.9 MPG.

 

Copy that. I'll do that to improve my driving habits too. Thanks

 

Long Range Automotive Tank Photo's Loong range auxiliary tanks

 

Long Range Automotive Tank Photo's Loong range auxiliary tanks

Buy a prius.

Not being a smartass.... it's just that an FJ is a solid body-on-frame suv. It's like a truck... but heavier and not as streamlined.

I'm aware that I'm not going to get the factory 21 mpg on this 160k-miles truck but at least I want to be close to that number.

My wife has a 2015 Versa Note, funny car and it's great on fuel economy. Go to hell small cars-with-great-mileage. I'm jealous!

 

Hang your hat over the gauges and enjoy the ride.

 

Thanks. I will. Any comment regarding regearing my FJ?

 

My first bet your mileage is so bad is the mud terrain tires. If you switch to AT it will probably go up a good mpg.

You should switch out your rear diff gearing to do the lift/tire size change properly. I've seen charts say a 4.56 rear for 33 inch tires, but the chart was for Jeeps, not FJs.

 

First of all, what did you mean when you said you "cleaned your oxygen sensors"?

There are two air-fuel sensors that, along with the MAF sensor, control fuel mixture. There are also two oxygen sensors that monitor catalytic converter efficiency. These sensors have a useful life of 85-100K miles. If your air-fuel sensors are beyond this mileage, they are unavoidably degraded and will not provide accurate data to the engine ECM, and will frequently cause poor fuel economy. If these sensors have not been replaced in the last 100K miles with OEM Denso sensors, they need to be, as accurate mixture control overrides anything else you might try to do to improve MPG.

There is no way to 'clean' either of these sensors, as the critical ceramic electrode is protected inside a perforated metal shell.

Assuming that your fuel-feedback system is functioning properly, 90% of any significant improvement in fuel consumption will come from modifying your driving habits.

As suggested, the fastest and most reliable way to see what's needed is to install some device that will provide real-time feedback on instantaneous fuel consumption. You will be absolutely shocked to see how little throttle, or how slight an increase in RPM, will drive fuel consumption down into the single digit range.

The fastest and least expensive way to get fuel real-time fuel consumption data is with an Bluetooth OBD-2 adapter ($24) that plugs into the OBD connector near your left knee, and the Android app Torque Pro ($5). You can run this on any Android phone, tablet, etc. In addition to instantaneous, long term, and 'trip' fuel consumption, Torque Pro can display hundreds of other important engine and driveline parameters (actual coolant temperature, ignition timing advance, transmission fluid temperature, air-fuel ratio, OBD fault codes, etc.).

Fuel consumption of single VVT-i FJs ('07-'09) can be as good as 18 MPG or higher with a properly maintained engine and conservative driving habits, even with some reasonable mods that add some weight or aero drag.

To achieve this, you need to:
1. Limit highway speed to 65-68 MPH.
2. Start off with minimal throttle opening, and modulate throttle to allow upshifts at around 2,000 RPM.
3. Lots of coasting to stop signs or stoplights, back off the throttle as soon as you see that a stop may be required, even if it is far ahead.
4. Minimal use of brakes: ANY use of brakes (aside from going downhill) is just wasting energy (forward momentum) that you burned fuel to produce.

I have a fairly heavily modified '14 AT (roof-top tent, sliders, heavy 'E' load range tires, skidplates, fridge, recovery gear, on-board air system, etc.) and I can consistently get 19-20 MPG on the highway.

If you install lower gearing or tires substantially larger on diameter than stock you will unavoidably see further reductions in MPG.

 

First of all, what did you mean when you said you "cleaned your oxygen sensors"?

There are two air-fuel sensors that, along with the MAF sensor, control fuel mixture. There are also two oxygen sensors that monitor catalytic converter efficiency. These sensors have a useful life of 85-100K miles. If your sensors are beyond this mileage, they are unavoidably degraded and will not provide accurate data to the engine ECM, and will frequently cause poor fuel economy. If these sensors have not been replaced in the last 100K miles with OEM Denso sensors, they need to be, as accurate mixture control overrides anything else you might try to do to improve MPG.

Assuming that your fuel-feedback system is functioning properly, 90% of any significant improvement in fuel consumption will come from modifying your driving habits.

As suggested, the fastest and most reliable way to see what's needed is to install some device that will provide real-time feedback on instantaneous fuel consumption. You will be absolutely shocked to see how little throttle, or how slight an increase in RPM, will drive fuel consumption down into the single digit range.

The fastest and least expensive way to get fuel real-time fuel consumption data is with an Bluetooth OBD-2 adapter ($24) that plugs into the OBD connector near your left knee, and the Android app Torque Pro ($5). You can run this on any Android phone, tablet, etc. In addition to instantaneous, long term, and 'trip' fuel consumption, Torque Pro can display hundreds of other important engine and driveline parameters (actual coolant temperature, ignition timing advance, transmission fluid temperature, air-fuel ratio, OBD fault codes, etc.).

Fuel consumption of single VVT-i FJs ('07-'09) can be as good as 18 MPG or higher with a properly maintained engine and conservative driving habits, even with some reasonable mods that add some weight or aero drag.

To achieve this, you need to:
1. Limit highway speed to 65-68 MPH.
2. Start off with minimal throttle opening, and modulate throttle to allow upshifts at around 2,000 RPM.
3. Lots of coasting to stop signs or stoplights, back off the throttle as soon as you see that a stop may be required, even if it is far ahead.
4. Minimal use of brakes: ANY use of brakes (aside from going downhill) is just wasting energy (forward momentum) that you burned fuel to produce.

I have a fairly heavily modified '14 AT (roof-top tent, sliders, heavy 'E' load range tires, skidplates, fridge, recovery gear, on-board air system, etc.) and I can consistently get 19-20 MPG on the highway.

If you install lower gearing or tires substantially larger on diameter than stock you will unavoidably see further reductions in MPG.

I deeply appreciate your input and for sure, I'm going to change many things in my driving habits. Thanks for this thorough explanation.

 

 

If you put oversize tires on your FJ then you will immediately get worse miles per gallon. The oversized tires cause your odometer to turn slower and you don't get credit for all the miles you drove.

Sent from my SM-G928V using Tapatalk

 

2011 stock, 18 in town & 20 hwy @ 65mph.

 

Ive got a 2007 with 35x12.5x17 km3s, raceline beadlocks, stock gears, and an M1 bumper with a winch. My ultragauge says I’m getting 12.5 avg mp3. I’d be happy if I was getting 14.

 

Honestly... I stopped even thinking of gas mileage years ago.

I added an extra gas can on my bumper so I could utilize my whole gas tank and have a plan B if needed.

 

My 08 had a 2.5" lift on 285/70/17at3w load C, and I was 13ish in town and 16-17ish highway. Just part of the brick life
My 14 TTUE has the wrangler asymmetrical MTR tires load E and I feel like im about the same as my 08 lol

 

Hi there,

I hope you can give me a piece of advice to improve my fuel economy in my 07 FJ Cruiser 4WD A/T Base, I'm struggling with its 12-14 mpg each time that I hit the road. I bought this truck for camping trips, long drives, 300, 500, 800, 1000 miles and it's killing me.

I've installed:

A set of 33 in mud terrain tires (I'll replace them for a 33-in Toyo Open Country AT III),
TRD performance air intake,
AFE throttle body spacer,
AFE 3 in exhaust system,
New spark plugs,
Cleaned MAF sensor,
Clean O2 sensors,
Changed CAM position sensor,

Even though it has improved on performance and torque, I still can see the fuel economy is bad, I'd say 14 mpg. I'm planning to regear it, probably with a 3.91 gear set for my 33 in wheelset but I was told that a 4.56 one is what I need.

What would you recommend?

Could be seized calipers. Used to have an 07 4Runner and I was getting 10-12mpg mixed and was BAFFLED at what it could be. Put it up on stands and sure enough I could barely turn the front wheels by hand. Decided to just do rotors/pads/calipers up front and next fuel up I was looking at at WHOPPING 15.5mpg city I think I hit 19 on the hwy once lol.

 

I didn't think about that. I jacked my FJ up on stands and I could see that wheel don't move totally free. I'll adjust those calipers and pads. Thanks for the hint

 

Zoiks!

 

I've learned to use this to measure my instant and average MPG for my old Mustang (when I owned it) and am using it for the FJ now.

 

But you can get a brand new, well-proven BAFX Bluetooth module AND a used Samsung 7" or 10" Android tablet for the price of the OBD Link unit.

Granted, the BAFX units is Android only, but the premier OBD monitoring app (Torque Pro) is Android only, anyway.

 

Driving slower can seriously increase mpg, also do alot more rolling instead of driving and hard breaking. Use the vehicles momentum at stoplights, etc.
55 mph in the truck lane will save you lots of gas, and definitely dont cruise more then 65/70ish on the freeway for long distances if you want to save gas.

 

FJ = SPG. Smiles per gallon!

Tundra crewmax = MPGLOL

Just trying to burn it all before they outlaw it.......

 

Stock tire size on aluminum wheels.
60mph max. Light on the peddle.
I consistently get 20mpg US unless really cold out


Sent from my iPhone using Tapatalk Pro

 

Hi there,

I hope you can give me a piece of advice to improve my fuel economy in my 07 FJ Cruiser 4WD A/T Base, I'm struggling with its 12-14 mpg each time that I hit the road. I bought this truck for camping trips, long drives, 300, 500, 800, 1000 miles and it's killing me.

I've installed:

A set of 33 in mud terrain tires (I'll replace them for a 33-in Toyo Open Country AT III),
TRD performance air intake,
AFE throttle body spacer,
AFE 3 in exhaust system,
New spark plugs,
Cleaned MAF sensor,
Clean O2 sensors,
Changed CAM position sensor,

Even though it has improved on performance and torque, I still can see the fuel economy is bad, I'd say 14 mpg. I'm planning to regear it, probably with a 3.91 gear set for my 33 in wheelset but I was told that a 4.56 one is what I need.

What would you recommend?

Well I have a 2008 trail team with just about everything you can put on it lift armor RTT I run 91 octane always I get 240 to to 253 miles a tank

 

I went from the original Honda Insight to a Prius. I bet I’m one of the only people that bought a Prius and my mileage got significantly worse. The biggest savings for me aside from driving slower on the highway that you’re doing, is all about maintaining momentum. Do a little more coasting to the red light, takeoff more slowly, those two things make a world of difference. In the Honda, I got really into it and would drive with slightly overinflated tires and a radiator block in winter, but I don’t recommend those things for our FJ’s. The scan gauge that somebody recommended is really good too to see how you’re doing, Both the insight and the Prius had live miles per gallon read outs, and you wouldn’t believe how bad it gets when you’re accelerating too quickly.