[lemony]

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,

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?

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?

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?

1. Buy a prius.
2. I never get more than 15 mpg with 4.56.. Never got 20 mpg brand new completely stock.

 

[FJtest]

Cruise control will cost you MPG's (unless it's the only way you can control your heavy foot ). It opens throttle wide and downshifts like hell to get you up hills and brakes to keep your speed going down. You can eek out a mpg or 2 through very disciplined pedal control.

I agree about cruise control triggering a screaming 1 or 2 gear downshift on the slightest upgrades ... when traveling cross country, I always drop out of cruise control if I see a grade coming up. What's odd is that with cruise control off, the engine will easily pull the grade in 4th without any effort, but if cruise control is on, the same grade will trigger a 4,000 RPM downshift to 3rd.

Cruise control doesn't have the ability to trigger any active 'braking'; it does cause the transmission to downshift, and the ECM cuts off all fuel flow to get a little more compression braking effect from the engine as long as the throttle is completely closed.

 

[Waffle]

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.

Do you have a link to the scan gauge you used? Luckily for me, the FJ is a weekend car, I have my civic during the week.

 

[FJC_April_2006]

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.

Hi Glenarch, If you would, could you please reply with the brand and model number scan guage you used that allows you to view your FJ's instant fuel consumption? I need to start doing this, too!

Thank,
Will J
2007 FJ with around 26k. First FJ to land in Alaska. Bought brand new in April 2006.
I work remote so I do not drive much, but when I do, I love my FJ!

 

[FLR1]

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

 

[pheller]

Make sure your tire pressure is correct. Maybe a little over. Low pressure can hurt fuel economy. I’m running Grabber X3 MT 33” with a 2.5” lift. Still get about 15 mpg on average.

 

[Little_Joe1]

When I run my 285 STT Pro’s on Steelies I see a consistent 2mpg drop with all other variables constant compared to stock wheels and tires.
This with no other added weight but with OME lift. Auto transmission.


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[Rafael_fjc07]

‘If you don’t like your mileage now, just put in those 4.56 gears! You’ll be crying.

I have an ‘07, basically stock, 17” wheels and All Terrain Michelin’s. No heavy bumpers, no big steel skid plates.

I get 16 mpg when all of my driving is in town And up to 21+ when I am all highway. In the winter I do a warmup, mainly to get the fluids moving.

I virtually never drive above 2,000 rpm, which is about 70 mph, except on an occasional pass.

As has been said many times on this site - pushing a brick through the wind.

I didn't get it... I'll be crying because those 4.56 gears will work as hell or because they're a waste of money?

 

[Ruuster13]

I didn't get it... I'll be crying because those 4.56 gears will work as hell or because they're a waste of money?

Because that gearing will keep you at higher rpm while driving on a highway. Amongst a few other things.

 

[Ragingbull02]

So...if I can ask - I did certain mods to my motorcycle which required a reflash. I added a fuel tuner because the fuel map was tight on fuel delivery. Results were superb and I averaged decent mpg, hp and overall happy with the result. For all you old hands here, would it benefit the op, or all of us for that matter, to get a reflash/tuner and dyno tune these vehicles?

 

[FJtest]

So...if I can ask - I did certain mods to my motorcycle which required a reflash. I added a fuel tuner because the fuel map was tight on fuel delivery. Results were superb and I averaged decent mpg, hp and overall happy with the result. For all you old hands here, would it benefit the op, or all of us for that matter, to get a reflash/tuner and dyno tune these vehicles?

There are several different aftermarket "tunes" available for the 1GR-FE engine that certainly add top-end power if only premium fuel is used, and modify the transmission shift programming, but I haven't heard any first-hand reports where ANY tune reduced fuel consumption.

Reduced fuel consumption is typically not the objective of an expensive ECM remapping.

 

[Glenarch]

the ones we used were the OBDLink LX with Torque APP. Now we use the Kenwood head units with Maestro RR, both truck FJs have speedo calibrations done for the larger tire sizes

 

[CabinCruiser]

What would you recommend?

RAV4. FJs have terrible fuel mileage, but nobody really buys them for that. Or return it to stock and enjoy 17-20 at best.

 

[CabinCruiser]

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:

 

[Powderhound]

2007 6MT, stock, 151,000 miles, used 99% for daily driving, 1% backwoods skiing. I run Kumho crugen ht 51 265/70-17 8 months and Bridgestone blizzaks same size 4 months, on stock alloys at 32 psi. No roof rack. New stock air filter, plugs, and mass air flow and throttle body are cleaned every 30k. Haven't changed any oxygen sensors but am thinking about it now after reading this thread! Also, I use 87 octane no name fuel because I drive like I'm driving Miss Daisy (shift @ 2000 rpm) and have not noticed any mileage difference with premium. Also use full synthetic 5w30 year round.

The ht 51's are a highway touring tire, very quiet and smooth riding, all season with the mountain snowflake symbol, and long lasting. The blizzaks are winter only tires.

Results over many tests: At 68 mph on non-mountainous highway only travel, cruise control on (in 6th only), just driver on board I get 21.5 mpg consistently with the all seasons, and 20.0 mpg with the winters. The fj is already warmed up before the starting and final fill ups. I don't know how much ambient temperatures or winter fuel matters. My guess is the tires cause most of the difference.

 

[CabinCruiser]

2007 6MT, stock, 151,000 miles, used 99% for daily driving, 1% backwoods skiing. I run Kumho crugen ht 51 265/70-17 8 months and Bridgestone blizzaks same size 4 months, on stock alloys at 32 psi. No roof rack. New stock air filter, plugs, and mass air flow and throttle body are cleaned every 30k. Haven't changed any oxygen sensors but am thinking about it now after reading this thread! Also, I use 87 octane no name fuel because I drive like I'm driving Miss Daisy (shift @ 2000 rpm) and have not noticed any mileage difference with premium. Also use full synthetic 5w30 year round.

The ht 51's are a highway touring tire, very quiet and smooth riding, all season with the mountain snowflake symbol, and long lasting. The blizzaks are winter only tires.

Results over many tests: At 68 mph on non-mountainous highway only travel, cruise control on (in 6th only), just driver on board I get 21.5 mpg consistently with the all seasons, and 20.0 mpg with the winters. The fj is already warmed up before the starting and final fill ups. I don't know how much ambient temperatures or winter fuel matters. My guess is the tires cause most of the difference.

What elevation? Air plays a role.

 

[norm356]

its interesting how many threads start out with a question from someone, and it ends up being a loooooong list of everyone posting what their mpg is

 

[FJtest]

its interesting how many threads start out with a question from someone, and it ends up being a loooooong list of everyone posting what their mpg is

True, but it seems like many of these threads start out with someone complaining about their FJ's fuel consumption, and how they can never get better than 12 MPG no matter what they do.

In addition to technical suggestions on how to keep the fuel feedback system operating correctly and hints on driving technique, providing actual long-term MPG data from multiple owners with both MT and AT models with various levels of mods provides some means of comparing what MPG you are getting vs what it is actually possible to get.

 

[Winterpeg]

aka Real-Life data vs what the window sticker says you should get....

 

[fjforles]

Get a prius, that will improve your gas mileage [emoji3]

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