Hello, Ive got a 99 4runner sr5 sport. Ive been averaging around 15mpg city maybe 17mpg freeway. I have 118,000 mi. been running amsoil oil in the crank, diffs and tcase. ngk irridiums, cleaned maf, chevron gas, 265/75's, 1 or 2 inch lift pp/springs. I do have a thule cargo box and live at 6600 feet. with cold winters. the truck runs great but 200-210mi filling 14 gal is brutal @ $3.50/gal. Ive read all the threads and have gotten tons of great info. do you guys think the cold weather, slightly biggger tires and that cargo box would produce these numbers. I did throw a code before i cleaned the maf, but not for 20,000mi. fuel filter, or front o2 sensor? ant input is appreciated. I know we all are trying to optimize performance and efficiency. thanks in advance. you the man.

 

The cargo box isn't helping. Remove the box and drive for a full tank and let us know what you get.

 

I will try that, but was thinking my round town driving is too slow, to affect mileage less, than 40mph. i figured the cargo box would affect mileage more at highway speeds. but will pop it off 2nite, and will report results after the next tank. thanks pruney

 

15 mpg city is pretty good for 118,000 miles. You could try changing the fuel filter. Is it and auto or manual?

 

I'm sure elton will chime in on this soon... with his 21mpg! whew. i thought that was impossible, but i got close...

went on a 300 mile I-5 run to vancouver, wa and got 20.9 mpg. and ever since then, been getting between 19.5 and 20.9 every tank. this is about 40% city and 60% highway. but still- average it out, and all city would probably be 17-18. i've done nothing to it, save an oil change (chevron 5w30 and napa filter). a newer air filter was in it jan. (from dealer), don't know status of fuel filter... i think you just need to go 600 miles on the highway, trick the ecu, and then get 19+ mpg from then on! worked for me

nothing in the back, nothing on the stock rack, 265/70/16 HTs. even had the a/c going about 50% of the time!

 

lol

 

before I sold my camry I had a thule bike rack on it and lost about 2-3 mpg. so like others have said try removing the cargo box and see what happens.

 

Here is my experience--

I commute 100 miles on the highway everyday. When I was 100% stock, I was getting averaging 20MPG. Then, all I did was put on 265/70/17's (I had 265/70/16's and 265/65/17's, and they both resulted in the same MPG) and it brought my MPG down 2MPG. I took very careful notes of my driving style, traffic conditions, even the actual gas station.

So, your main culprits are the bigger tires and cargo box. Cold winters don't have anything to do with MPG. The winter gas mixture will drive the MPG down, too.

You should buy another set of rims and put stock tires on there if you want better MPG.

 

Yep... Lighter wheels. Stock 16x7's weigh in at exactly 22.5 lbs.

www.centerlinewheels.com

Stingray III's, Champ XL's are just a couple examples of 16x8's that weigh 18 lbs per rim. They go on overstock sale from time to time for $150 in polished finish.

 

I have a California spec 1999 4Runner 5spd 3.4L and I get about the same. I never get any lower than 16mpg anywhere though. The highway mileage just depends on the speed with the 5spd. If I drive at 50 mph I can get 20mpg. At 75 mph when I drive on I-90 to and from school I get 18 with a bike rack. I put a TrueFlow filter in and have been getting better mileage. I bet any filter would do it though, the other was dirty.

 

Remove the cargo box......I lost 2-3 mpg when I put my safari rack on

 

I average 13mpg. Haha. I guess thats what a basket on top, 33's with steelies, 4.88's and a couple extra hundred pounds throughout will do though. Kinda sucks. Oh well.

 

I have a load warrior on mine and those racks really won't hinder mileage aroiund town,it's once you're over 50mph the rack will become a problem. With the rack or w/o I get anywhere from 15.5 to just a hair over 17mpg around town with a little highway. I get just over 250 a tank and usually fillup with 15 gallons on average. I have 127k on the odo and D load rated Nittos.

My mom gets just over 20mpg with almost all highway in her '99 Limited.

 

p nut is right on, I went from 17-18 in town and the occasional 23+ on roadtrips but when I upgraded from all season tires to 265/75/16 8ply Wildcountry TXR I dropped almost 2-3 in town, almost 3 on roadtrips. 2000 4x4 runner with 121k, dino oil in diffs and dino tranny fluid, all maintainance work done on time, including tranny flush, wires, plugs, et al.

 

i got 19.7 on the last tank, we will see how i do this tank as i just did the deck plate mod. I would think that it will be better but it hard not to get in it when it sounds so cool.

 

I was getting almost 13 MPG a few weeks ago trhen I did the whole Seafoam treatment. OH HOW I LOVE THE SEAFOAM!!! I've been through three tanks since then and now my average is just a hair over 19!

 

Post fuel economy stuff in this thread: https://www.yotatech.com/forums/f2/we-need-more-3rd-gen-4runners-86034/

 

I just pulled 19.6 MPG on the I 5 LA to SFO. The deck plate mod works last week with out it on the same drive i got 17.5 mpg. So with that i think that i am going to install a biger deck plate(like 6"). we will see how it dose on the wa back to LA on Sunday

 

i have a 91pickup, i filled up and got 352 miles to the tank before i filled up again...and when i filled up after that i put in 17.6 gallons which puts my MPG at exactly 20MPG...and im prolly getting more cuz i have bigger tires without any compensation on the speedo, odo, or trip. thats all rural town driving tho...soon as i get on the highway my gas mileage decreases, but im denoting that to my truck having the aerodynamics of a brick, going 75-80mph, and being over 3k rpm's...not exactly prime rpm's for max fuel mileage...

 

With 265x70x16, no lift & stock wheels I was getting 19 mpg in the 98 4runner. With a 2.5" Revtek lift, 285x75x16 and new Helo wheels, I get 15-16 mpg. ((Man...just filled up (again!). $40+ for 15 gallons??!!...))