I have a 99 4runner and cannot figure out how many gallons of gas the tank can hold. The owners manual says 18 or 15.4, but when I run it to empty and the light comes on and still drive 20 more miles, I only am able to put in 13.8 gallons! Whats up with that? The dealer couldn't give me more information. Can anyone help?

I am not really sure about the max capacity but there is a TSB for the fuel gauge reading in accurately. This causes the gauge to come off of full very quickly and the fuel light to come on when there is plenty still in the tank. If it bothers you, you can get the new fuel sender but it means dropping the tank to put it in. Personally, I just got used to it.

i have a 97 4runner, and i have a somewhat similar issue with the gas gauge. It reads "normally" till it gets low, and then the light comes one, when about 14.5 of the 18.5 gallons is comsumed. I have just grown used to it.. Its actally really nice for road trips. Light comes on, i still have about 4 gallons left to go on.. more than once that has been a good thing.

Max capacity is 18.5 gallons. And yes, I've verified that several times. It's the same for all '96-'02 4Runners.

It sounds like you haven't had the fuel TSB performed on it. (TSB = technical service bulletin). The dealer performed the fix for free if you went there when the TSB came out. It's been at least a few years, so you might need to pay to have it done now. (I'm not certain if free TSB fixes "expire" or not).

Prior to the fix, the low fuel light comes on with 4-5 gallons left. One time I remember running out of gas 97 miles after the low fuel light turned on. It would also come off of full pretty fast. The gauge did other screwy things for me too. One time I ran out of gas while the gauge still showed 3/4 full.

After they performed the TSB by replacing the instrument panel and fuel sensor in the tank, the low fuel light now turns on with about 2-2.5 gallons left. The gauge acts great now.

If you do a search on this forum, you can find more info about it.

(edit) Here's a link to a copy of that TSB still posted on a friend's web page:
http://www.reapur.com/car/4runner/fuel%20tsb/tsb_el010_p4.pdf

An old forum post about the topic:
Link here

Looks like it was only fixed free under the original 36 month/36,000 mile warranty.

To further confirm, 18.5 gallons.

I learned to live with the inaccuracy and go by the trip meter. 260 miles meant to fill up...

Mike

Thanks for all the feedback. It has been very helpfull. The last one was the best.

The previous owner thought the mileage was horrible on the runner but it was just the sending unit issue.
I've learned to live with it.
When my light comes on......... I have 5 gallons left.
I can usually go 300 to 325+ on a tank.
One of my pet peeves with the runner. I'm always filling it up! Kenny S>

I should also mention that my 4Runner is heavily modified which has affected MPG to where it didn't level out to when it was new. To know your exact mileage you will need to do some calculations.

Also, at 260 mi. it wasn't out of gas but it indicated that it was time to find gas and fill up...

Mike

Hi Ben,

Like I said when you wrote to me a while back, it is 18.5 gallons. Glad you found this forum, you will find a lot of really knowledgable people here, like my friend Jeff the Marmot. Welcome to the forum!

-Sherpa

One of the things I've learned about the 4Runner gas tank design is that it starts burping gas back through the vent pipe and shuts off the nozzle at a point where another gallon of gas will easily go in if you feed it slowly..

It seems to help if you turn the filler nozzle horizontal with the filler hose to the rear.

And on a trip out west where we were going into a really remote area and needed all the gas we could stuff in.. I learned that you can actually stuff more than a gallon in the tank (and extra 1/2 to 1 gallon.. e.g. 1 1/2 to 2 gallons total) if you feed it reallllll slow..