I just got a new job and I'll be driving about 2000 miles/month (@1400hwy & 600city) starting in about ten days. I've had my truck for over two months now. I like everything about the truck, and wrestled with a smog gremlin, but finally got over that hurdle (the pre-cat O2 sensor wire was damaged on the way to the ECU), and passed smog without an issue after it was fixed, but my fuel consumption remains the same! So far I have replaced the timing belt, oem upstream O2 sensor, oem spark plugs, new air & fuel filters (Pep Boys), and changed engine oil (Castrol 10-30).

What I have not replaced is the rotor, cap, and spark plug wires. These seem fine, and I'm not having any type of engine miss or anything like that. I posted this on another thread, but here's the mileage I'm getting:

Only city driving with AC: @12-13 mpg
City/hwy mixed with AC: @13.5-14.2 mpg
All highway with AC & headwind from Palm Springs to LA: 15.4 mpg
All highway with AC & tailwind from LA to Palm Springs: 18.3 mpg
All highway without AC & tailwind LA to Palm Springs: 19.37 mpg

Do these numbers make it seem like there's something wrong with the engine? If there was something wrong with it, like one of the sensors not working properly or if it was running rich for some reason, would it still pass smog?

By the way I am running 31x10.5x15 and the stock size is supposed to be 225x75x15. I've checked many times while driving on the freeway (by checking the distance to a certain city), and it's exactly 10% off. For example, if the odometer says I've done 100 miles, when calculating mpg's I use 110 miles.

Finally, even after passing smog, during sudden downshifts on the freeway (when I step on the pedal and the rpm goes to @4k) the engine light came on, with code 27 (downstream O2 sensor issue) twice so far. My mechanic thought he fixed it as he found something wrong with the wiring, but it hasn't solved the problem. IF the signal from the downstream O2 isn't getting to the ECU, would I be getting bad mpg?

I don't want to sell this truck, but I just can't afford to pump that much gas into it either When new, it was supposed to get 15city/19hwy (as mine is the 2wd model). I was thinking that If I'm able to fix whatever is wrong (described above) and then spend @ another $400 on the following:

1) ISR mod - $50
2) Crossover elimination $200
3) High flow offset Borla muffler $130

Would I be able to get @16/17mpg in the city and 19/21 on the highway? is this possible, or is it just wishful thinking??

 

I'm gonna say it's probably wishful thinking. I get almost 16 on the highway, about 12-14 around town if i'm lucky. I have an ISR, and a nice hi-flow exhaust setup. It's just not gonna happen with this motor...

 

Damn... you've got the set-up I just explained to try and improve mpg's... Guess I won't even try Thanks for your input!

 

No problem, I feel safe in saying that you would get the same response from any 3.0 owner on here, it's been debated over and over. The only thing I don't have that you mentioned is headers, however for the price and benefit I would quickly get a v8 swap going rather than bothering with this dead weight motor. Good luck to you, and if you're looking for another 4runner type vehicle just look toward a newer model, those numbers are far more realistic from what I have seen.

 

Okay, I'm thinking of maybe a 2001-2005 Rav4. I would like to keep my budget to about $8k, but can stretch to about $10k if it's a good car. My main priority is that it gets over 25mpg on the highway and its relatively comfortable. Other options I suppose are maybe an older Lexus ES300, camry, or accord? I don't mind an older, but reliable 4-cylinder SUV... any suggestions??

 

I think you're onthe right track. I'm looking for a dd right now as well actually, but I would like awd so I'm leaning toward a subaru. If you're looking for amazing mpg's tho you may want to look at a tdi vw.

 

keep the truck, pick up a nice mid 90's Japanese compact for commuting duty.

 

8 mm wires will help your mpg, manual hubs will help. alcohol/methane injection will help. stock tires will help. im getting about 18 mpg's driving like a race car with my 3vze.

 

x2 thats what i do.
95 acura integra 35 mpg...if i keep my foot out of it.

 

alcohol injection x2, this seriously helps even on this motor!

no need for an expensive controller either, just an on/off switch with about a 2-3 gph nozzle will net you at least 1mpg on average, especially in town driving where you are accelerating a lot. plus it cleans your engine

 

5 speed swap lol

 

Yep...

 

goin back to the stock will help, less rollin resistance, and less weight, and maybe a possible regear, if you want to keep the 31's. But I would go with a cheap 90's DD, like previously suggested, and keep the Toy for fun stuff.......

 

I get anywhere from 19.3 to 19.8 mpg going back and forth to work I have 31x10.5 its a 58 mile round trip 6 days a week probably 45 miles highway and I have 256,000 miles on my old 3.0

 

That mileage sounds about right. I have the same motor and auto trans. 31X10.5x15s and I get almost get 17mpg highway without ac. I am thinking about a stock set of tires to drive around with just for the gas savings.