When my truck was dead stock a few months ago when i bought it, i was getting about 25-26 mpg freeway. and now after doing the following: new plugs, new magnaflow catalytic converter, new flowmaster muffler, new 2.25" pipes from the headers to the tip, Lucas oil everywhere i can put it, advancing the timing, the air box mod, the AFM mod, I am currntly getting 21-23 mpg freeway! Any ideas as to why with all these mods I am not getting better mpg ..... but worse!!

 

you should be so lucky w/ that mpg!

my guess is that you got some performance mods in there and i betcha you've been testing the limits of those mods. in my many years here, ive seen posts like yours esp after people put in new cat backs, deckplate, SCs, etc.

on your next few fill ups, take it easy on the throttle and see what your mpg looks like.

bob

 

I agree with bob its amazing how much better your mpg will get if you keep your foot out of it. And yea your lucky you get in the 20's cuz i still get around 16.

 

Keep a vigilant eye on tire pressures. That's one area that many people don't think about. Low pressure is a mileage killer. I check mine once per month and keep them at 35 psi (that's for my P225's and my 31's). As the others have said, a light foot is helpful, too.

Mike in AR

 

i wish i could complain about getting 23 MPG. i get 12 on a good day. and with gas this high im not doing so well.

 

What plugs are you using?
What did you advance your timing to? Do you now need higher octane?
Other than that, I also would bet you are enjoying your new-found power and gassing it more than you used to.
I would be ecstatic to get 20 mpg.

 

AFM mod would be the culprit in my opinion. Once you screw with stock control systems you will never get it back. I learned this the hard way.

 

I woul love to get the mileage you got. I get 11 on a good day!!!!

 

Maybe advanced timing would cause it? I'm getting 16.5 (yes, along with everyone else, on a good day) and would kill for 20+. I didn't buy a 4Runner for the mpg though. Moreso for the reliability, quality, and of course the excellent Yotatech community!

 

When I advanced the time on my 3.0, it helped mileage. Of course I had to start buying mid-grade fuel at about .10 per gallon more. But I like the pep the throttle has now.

Mike in AR

 

ok contrary to everyones thoughts... I know for a fact its not a matter of me being a little hard on the throttle. When I tested the mpg, it was on the same stretch of road over 240 miles before and after (on my way to moab !!) and each time it was a constant 70 miles per hour. So no, it can not be the more aggressive driving. Besides, I have not even felt a noticable increase in any performance really. As for the AFM mod, i tried it for a while and was disappointed with the results (nothing) so it is sent to the original position... so that is not the culprit either. My plugs are Bosch Platinums, the timing is set 5 degrees forward, I do need to run a little higher octane gas, which i do, the tire pressure are check at least twice a month.
And for everyone saying I shouldn't complain about my mpg's ?? First of all I have a 4 banger, and it seems everyone that said I shouldn't complain is running a V6. Second is that after being dead stock and spending all the time and money on the mods I have done without seeing any increase in performance, or mpg's... I think I have a right to complain!!

 

Calm thyself...

I also have a 4 Banger (do you have the 22RE?) and I am getting approx. 20 - 22 highway. How many miles do you have on your truck? Could it just be from old age?

 

ya i would have to agree with ya! BTW how much did you end up spending on all that stuff?

 

DING DING DING WE HAVE A WINNER!!!!

22RE's HATE any plug but a NGK/Denso... mine stopped running 400 miles after putting Bosch plugs in, wouldnt even idle.....

Switch back to OE plugs, and go from there..

Have you changed tires?? Also, with different weather your mileage will change...but should be better in the summer...

 

Jimmeh:

I do have the 22re. I have 172945 miles one it, and no.. that is not the problem of the "old age" being how it has not been that long since I have done the stock mpg measurement and the after upgrades measurement. Im talking like no more than 5000 miles. I did all the upgrades all at once (well within a weekend)

 

My 22RE gets 18-21 with 33's, hair less with the 35's. I have 160K, and it still runs great.

If you are referencing one hwy trip... in addition to the plugs I told you about, what was the weather like? This will have an effect on mileage... If you had 5mph difference in wind that can make that much of a difference in mpg... You should track mileage on a tank basis...

 

are different plugs along with all the mods i did really going to affect my mpgs that much?? weather is not a factor being how i did the tests in pretty much the same conditions, warm, sunny dry. the tires are the same.

881stGenRunner :

just so ya know, my total exhaust system was about $425. Air box mod, AFM mod, Advancing the timing= free! Plugs= $12, K&N filter= $45, Lucas oil= $10 per quart, so yeah do the math, its alot to pay to see a DECREASE in mpg's !!

 

My 3.0 didn't like Bosch Platinums, either . Stickin' with NGK.

Mike in AR

 

When I did full exhaust, header to hi-flow mufflet, I saw an increase in MPG. I would guess that the decrease is due to something like the plugs or the timing advance. It's just not what the computer was designed for. And typically perfomance comes at lower mpg, when you using the performance.

Have you changed your O2 sensor? A degrading one of those can cause worse mileage.

And you said that the old test was months ago, which would put you in winter...generally colder. Also was there traffic the first time? Several other cars going with you will increase you mileage, even though this isnt nascar drafting still works.

25-25 is also awefully hi, was this on one tank only? Did you fill up both times from the same pump? Pumps can read a few percent off from fill to fill...there could be error right there. I once got 24 MPG on my 4runner towing 5K pounds over a montana pass...I know that wasnt correct, but the math was there... I even tried adding more gas, but the math said 24mpg.

I am not trying to call your bluff or anything, just throw more uncommon ideas out there..

 

well maybe i will change those spark plugs. see if that does anything. But i am still at a loss because with all these mods i have not really physically felt a change in my performance at all.