Optimal MPG for FJ Cruiser (1 Viewer)

[imzjustplayin]

I'm creating this thread in hope that people will post the things they've noticed or they've done in order to get the best MPG from their FJ Cruiser. I'd be interested in hearing what MPG people get with their FJ at a given cruising speed. I have a sneaking suspicion that if you could drive the FJ at a constant 35mph, you'd get better mileage than had you continuously been driving at 55mph.

First off I would like to ask a question of my own:

When is overdrive enabled on the FJ cruiser? 35mph or 45mph? What speed does torque converter lockup occur at? And also, does the FJ allow the utilization of overdrive AND bring the RPMs down to 1000? It just seems like that once overdrive is enabled, the FJ sits at 1500RPM and climbs from there (depending on speed). Has anyone DYNO'ed the FJ cruiser yet? Does it have graphs from idle all the way to the rev limiter? I believe I saw one DYNO sheet but it started at 1500rpm and even then it didn't seem to make much sense in the numbers it had. 25lbs of torque at 1500rpm? Seriously?

 

[tddfj]

dont know if the overdrive is set for a certain speed. i live i a subdivision all the way at the back and at 25 mph it will go to 5th gear. and rpm drop to below 1000 a lot of timesi will put it in 4th gear when i am on streets for a good distance that are 25 to 35 mph because trans likes to shift a lot from 4th to 5th because of the electronic throtle and trans being tied together to work better. just getson my nerves.

 

[imzjustplayin]

dont know if the overdrive is set for a certain speed. i live i a subdivision all the way at the back and at 25 mph it will go to 5th gear. and rpm drop to below 1000 a lot of timesi will put it in 4th gear when i am on streets for a good distance that are 25 to 35 mph because trans likes to shift a lot from 4th to 5th because of the electronic throtle and trans being tied together to work better. just getson my nerves.

I don't think it shifts into 5th gear at 25mph because I've noticed that once it gets to 34mph it will shift one more time.

 

[tddfj]

no i know forsure its in 5th because ive counted the shifts before you need to hold a steady speed for it shift to 5th.

 

[Niner]

I think 5th gear at 25 and lock the converter at 35

 

[Blues Dawg]

No T/C for me. I've got a manual tranny. Stuff impacting mileage that I've noticed:

The Good - I changed the exhaust to a magnaflo muffler and installed the TRD CAI and gained about 1 mpg in the city and and went from about 16.5 to 19+ on the highway (cruising in the 70-75 range).

The Bad - BFG AT KO's Suck (gas). Second truck with these tires and the cost me at least 1-2 mpg on both.

Take into account I also am running the OME lift and OEM roof rack - both will impact aerodynamics and reduce mileage.

Carl

 

[spaldam]

I've got the 6MT with TRD package (i.e. BFG's). I get around 15-16 on average, mostly freeway at around 70 MPH. I also can't go much slower then 45 in 6th without lugging the engine and that's on a slight decline. 5th does fine above 40ish.

Keep in mind that your driving habits will have a big effect too, and just because your going slow in a high gear doesn't mean you're getting really good gas mileage. If you travel faster, using the same amount of gas in the same amount of time, your MPG improves because the distance you traveled in that amount of time also improved. If you have to push on the peddle too much, you'll do better if you down shifted.

 

[DominicG]

i went from 12mpg (before and after lift and 33"s) average to around 18mpg average. keep it under 2k rpm all around and your mileage will jump. 21-2200 rpm is where the gas starts to disappear fast

 

[nashvegas]

Dominicg- Did Your Engine Light Every Come On After Installing The Cold Air Intake. I Just Installed A K&n Cai And Both The Engine And Vsc Lights Are On. Any Ideas?

 

[Blues Dawg]

Dominicg- Did Your Engine Light Every Come On After Installing The Cold Air Intake. I Just Installed A K&n Cai And Both The Engine And Vsc Lights Are On. Any Ideas?

It came on when I developed an air leak, effectively bypassing the filter. Had to have it reset. Also, apparently this may alos happen if you do the install without disconnecting the battery. Inspect for leaks in the air supply connections and if none found, try disconnecting the negative side of your battery and reconnect after about a minute.

Carl

 

[imzjustplayin]

I've got the 6MT with TRD package (i.e. BFG's). I get around 15-16 on average, mostly freeway at around 70 MPH. I also can't go much slower then 45 in 6th without lugging the engine and that's on a slight decline. 5th does fine above 40ish.

Keep in mind that your driving habits will have a big effect too, and just because your going slow in a high gear doesn't mean you're getting really good gas mileage. If you travel faster, using the same amount of gas in the same amount of time, your MPG improves because the distance you traveled in that amount of time also improved. If you have to push on the peddle too much, you'll do better if you down shifted.

Well the only way to know how much fuel is being used depending on the RPM would be to hook up to the OBD and check, which is what I'm planning on doing, also doing a dyno would help tremendously.
I was just driving on the highway today at 55mph and mind you I had just filled my tank half way and already it has lost about 1/4 of that half tank which really pissed me off since I had only driven 37miles total! How accurate is this fuel guage? Two things, either its accuracy seems to change wildly or I am getting worse mileage when driving on the highway then when I'm driving in the city at 35mph which brings the engine down to around 1000rpm opposed to 1500rpm at 55mph.

 

[spaldam]

The thing I would wonder about is that you only filled it to a half tank, or so you think. I find that fuel gages aren't very accurate when you first start the vehicle. To truly gage you're gas mileage you have to fill the tank all the way and pay attention to how much fuel when it, and how many miles you want from the last complete fill up. Keeping a running total also helps average out the discrepancies

 

[imzjustplayin]

The thing I would wonder about is that you only filled it to a half tank, or so you think. I find that fuel gages aren't very accurate when you first start the vehicle. To truly gage you're gas mileage you have to fill the tank all the way and pay attention to how much fuel when it, and how many miles you want from the last complete fill up. Keeping a running total also helps average out the discrepancies

The tank is 19 gallons, if I put in 8.7 gallons and the guage says that it's half way filled, I think I should believe it considering how late I am to fill up. One time when I did a full tank I got 19.002 Gallons and it's a 19 gallon tank! I still have the reciept.

 

[Woodeye]

The tank is 19 gallons, if I put in 8.7 gallons and the guage says that it's half way filled, I think I should believe it considering how late I am to fill up. One time when I did a full tank I got 19.002 Gallons and it's a 19 gallon tank! I still have the reciept.

You're a lucky guy! Let's go to the track or the casino! How do you get the FJ to the gas station with a totally empty tank?


Dick

 

[Blues Dawg]

One time when I did a full tank I got 19.002 Gallons and it's a 19 gallon tank! I still have the reciept.

I'd question the calibration on the pump

 

[Blues Dawg]

Did I mention I got rid of the BFG's (285/70/17) and put on Nitto T-Grapplers (315/75/16)? Well my odometer mileage went up! I'm now getting slightly more clock mileage w/ the Nittos so, when calibrated for size, I'm getting definitely better mileage.

 

[spaldam]

i went from 12mpg (before and after lift and 33"s) average to around 18mpg average. keep it under 2k rpm all around and your mileage will jump. 21-2200 rpm is where the gas starts to disappear fast

I've got the 6speed manual (basically stock), and tried to follow you recommendation. I got slightly worse gas mileage (15.2 MPG - normally closer to 16 MPG). The very next tank full I took a mostly freeway trip (about 2hour of driving), at 75 MPH most of the way, putting the RPMs between 2500 - 3000, and I got 17.5 MPG.

P.S. I use a very precise MPG calculator (and costs tracking) program on my Treo, so I'm sure the numbers are accurate.

 

[SurfPonto]

I've got the 6speed manual (basically stock), and tried to follow you recommendation. I got slightly worse gas mileage (15.2 MPG - normally closer to 16 MPG). The very next tank full I took a mostly freeway trip (about 2hour of driving), at 75 MPH most of the way, putting the RPMs between 2500 - 3000, and I got 17.5 MPG.

P.S. I use a very precise MPG calculator (and costs tracking) program on my Treo, so I'm sure the numbers are accurate.

With my MT6 I notice if I am able to keep it below 70 mph my mpg jumps.
I got close to 20 mpg when I did this. When I drive it hard it drops to 16 mpg/


Bob

 

[ckline]

I'd question the calibration on the pump

either that or somehow you coasted in on fumes and filled up to the cap?!?

Over the last week I have tried to keep the rmp's below 2k, in the city and highway. I gained maybe a half mile to a gallon vs the way I usually drive it...harder and faster. To me a half mpg isn't all that big of a deal.

Some of the other threads on the CAI are not showing as much of an increase in gas milage (sometimes only an exra mile a gallon). HOW are you guys pulling of 20mpg (what octain are you running)? Do you drive on completely flat land? I WANT 20 MPG, i just don't understand the variance between all the drivers. I have a 6, so its easy to monitor RPM's. Is the CAI truly worth it?

 

[IBFJC]

MPG

Questioning fill ups now after reading this thread...Just filled up gas light was on, receipt said 14.99G...Did I have five gallons left with the light on...???...I do a lot of city driving...I went 239 miles with 19 gallons, I get 12.57 MPG...with 15 gallons I get 15.9 MPG...91 octane just went over $4...will have to keep a close eye on it...also trying lower octane...more to follow...