94 3.0L V-6, 4x4, Automatic, 4:56 Gears, 31" Tires, Intake Mod, Downey Headers with 2.5 Exhaust all the way and it only averages 17 to 18 mpg. when it's babied. That a mix of highway and city driving but mostly highway.

Well I took a real good look at the vacume hoses and they all look good as new.
Should they be replaced simply because of thier age?


Best regards,
Glenn Schentag

Thanks for the response.
Do you know of a way for me to check the air tempreture sensor without replacing it? and is that the thermostat you mean?

Thanks again

Glenn Schentag

Thanks,
Your truck most resembles mine.
I'D BE THRILLED WITH 17MPG HWY OR CITY.
As of my last tank, 16 gals went into 220 miles @13.75/MPG
all most all of that was highway at 55-60mph. No 4x4.
If I could average 17mpg I'd be a happy camper. I'm just putting too many mile to be happy with 10-14.
Thanks for your thoughts. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Sounds about right but are you using US or imperial MPG ? I run a 88(190) degree thermostat from a v6 camry and it improved my milage especialy in cold weather . 20 mpg (imperial) is the best I ever get.

I have lockers, 5:29's, 35's, and I get between 20 and 21 driving to and from work. That's thru the hill country. The only motor mod I have is an EB RV cam. Stock exhaust, ect.

I can see an auto costing you about 3 MPG.

Granted, I have a 22re, but either way 10-15 is pretty bad. My wifes Suburban does better than that, and it weighs twice and much and has two more cylinders.

How did you test the O2 sensor ?

I have a '95 4Runner, 3.0, auto, 31's and 4.88's.
I get 18 mpg around town.



Fred

This is good advice, especially for your 3.0/auto since it is a known/common problem.

When the t-stat goes bad, it doesn't open when it should. This keeps the hot coolant from getting to the engine temp sensor. The engine thinks its still cold, so it runs a richer fuel mixture and also keeps the tranny from going into overdrive and lets it rev higher before down-shifting. It is designed to do this to help get the engine up to operating temperature more quickly to reduce smog emissions. This combo makes for very poor fuel economy when the t-stat is bad. The t-stat is cheap/simple place to start troubleshooting.

A co-worker of mine had these exact sypmtoms and the t-stat fixed it. He was grateful!

Hi there,

Thanks for the response.
A local mechanic said the O2 sensor was putting out reading a voltage that would indicate rich to the computer. However the computer does not make the appropriate adjustment.

I have been out of town for a week and have not spent any more time on this. I am going to do the thermostat next. That sounds like an inexpensive test

Thanks again for you input.

I'll post my results.

Cheers,
<img src="/forums/images/graemlins/cheers.gif" alt="" />
Glenn