I understand this thread may have been beat to death in the past, but I was wonder your thoughts... I had a 2005 Chevrolet 2500HD woth 6.0L. Damn awesome truck, but the MPG wasn't so good towing. I installed the Hypertech chip and I didn't notice anything. then I took it back to 4wheel parts for a Gibson exaust trade and then also installed an Airraid coold air intake. At this time I noticed a differance in MPG, not so much HP but better MPG.

My questions, can I do the same for my 94 3.slo? also, does anybody make an aftermarket Mass Air Sensor that will help with the MPG? will a larger exhaust and intake help with the overall MPG?

Also, why does it feel like I have a load allllll the time??? I was told by an old friend this weekend that I should install Manual Locks as the front driveshaft is spinning full time on the freeway and this will be a load on the drivetrain. What are your thoughts on that?.

I'm just freeken amazed, this is the first car I've ever owned that will not make it to Las Vegas on a full tank. I can't understand, I see hundreds upon thousands of mid 90's 4Runners and assume they are all getting better MPG than I. is 16MPG about average? my 6.0 Chevy got better and my 6.6 Diesel gets 21 avarage at 65MPH. Luv my Yota, but damn, Fuel cost is killin me.

 

couple things:

1) Swap it to a manual if its an automatic.

2) Volant, K&N, or you can do the ISR mod with an open filter as an air filter... should help a little but not much.

3) The exhaust is very restrictive on these v6s. Headers supposedly help ( i had them on mine, but never noticed an increase in mileage, I found myself pressing the gas down more because of the sound ) but you can probably do a cat back and might help it a little.

4) gearing. what tires are you running? If you're running 31s, try going to a 4.30. if you're running 32s, try going to a 4.56. if you're running 33s, try going to a 4.88. 34s+ 5.29s.

5) less skinny pedal.

 

6) 3.4 swap

My 88 3.0 automatic is a slug.

:wabbit2:

 

What's an ISR MOD?

not sure if the headers are legal in Cal?

31" tires and not sure what my gearing is?

I don't have a heavy foot. even when the posted speed is 70, i still set CC for 65. doing everything I can to get better MPG. it's not a commuter, but still don't like filling the tank in this tank.

Gearing will prolly help as every little tiny hill climb on the freeway, I'll need to hold it at 4K RPM just to keep up with traffic.

 

an ISR mod is a relatively cheap alternative to an intake. search it, theres tons of info on it.

Headers are smog legal in california. Search Doug Thorley headers or LC engineering headers. you need the LEGAL versions. they sell both smog legal and illegal

 

16 MPG is average, and there's not a lot you can do to change that.

You can get a new engine computer manufactured specifically for that application that would probably make some difference. Engine management systems have come a LONG way since the late eighties/early nineties. I'm sure that would be cost prohibitive.

It's an early fuel injected engine in a 4000 pound vehicle. It is what it is.

Also, as you said, it's been beat to death (in multiple threads).....so why start ANOTHER one??

 

I am getting 21-23 on average in my 3.0. I "tuned" the AFM and it seemed to help the torque and mileage, not by a lot, but it was noticeable. This is on 5 speed manual, manual hubs, 31" tires, stock gearing, stock headers, exhaust, and intake.

 

For what it's worth, I have noticed that mileage is pretty speed-sensitive; there is about a 10% difference between 65 and 61mph. (You can do your own calculation for whether it is worth it either way).

I get about 20mpg on the hwy, and 15 "in town." (But I live in a hilly area.) And I'm perfectly happy with that.

 

OK, share details on how you "tuned" your VAFM~

Are you talking about changing the adjustment inside it?

And bystock headers I assume you mean stock exhaust manifold...?

 

ISR mod if nothing else frees up like 100 cubic feet in the engine bay... looks way better, sounds different and may help net a fraction of a MPG for ya.

I have alky injection on mine (2gph nozzle) running a 50/50 mix of dH2O and methanol, it seems to help quite a bit with power but especially mileage. Also replace O2 sensor and stuff like that if they're old, I picked up stupid mileage with just a new sensor (original had like 160k on it, replaced it and went from 16 to 20mpg's, no joke.) lately, I'm lucky to get more than 17mpg's the way I drive.

 

Yea, tell us more...

 

What about the mass air sensor, anybody doing anything with those any more? i was going to get one for my last 6.0 Chevy and if I can remember they were about $400 and sure to get better MPG as long as you can keep your foot out of it.

 

anybody heard of this Savicorp DynoValve?. its some after market electronic PCV valve that will help increase MPG. My company has many vehicles that get 10 to 12 MPG and we are in the process of installing them on our service vans as we speak. from the website...
DynoValve ® Overview

 

x2 ^
when you wear out the 3.slo swap a 3.4 and you will get what you want/need, more power and better gas mileage.

 

For the 90 quadrillionth time...YOU HAVE AN AIR FLOW METER(AFM), YOU DO NOT HAVE A MASS AIR FLOW SENSOR(MAF).They are not equivalent. One does not do the exact same thing as the other, one is for metering air flow(in terms of volume), the other is for sensing air flow(in terms of mass). Volume ≠ Mass.

An AFM signal can be calibrated/adjusted mechanically(by setting the vane return spring tension). A MAF sensor signal is not adjustable or able to be calibrated mechanically. One is much easier to tune with than the other...take a guess which...

You can also play with the base/initial ignition timing advance. More advanced tends to yield better engine performance.

And/or run higher octane fuel. That alone will get you better mpg without having to do a thing(complements of the ECU via the knock sensor signal). Though it might not save you any money on gas, you'll also gain some extra HP with that extra mpg. It pays for itself one way or the other IMO(which is why I run premium in all my vehicles). And it can actually save you a little money over regular in the long run, depending on how you drive.

All the details on how to go about experimenting with the things I've mentioned you will find if you search for them.

PS, that PCV valve mod I can promise you won't get you squat in terms of mpg.

 

what uhhh, would that,, even have to do with mpg?
Didnt realize the standard pcv system had huge mpg robbing flaws..

And yes I visited the web site. Doesnt really explain how it helps by doing what it doing.

 

There are multiple threads about this. You open the top of the AFM and there is a gear that you adjust to tighten the spring that tensions air vane. Simple ten minute job. You should be able to find a detailed thread by searching for AFM tuning or similar key words. I had the thread bookmarked, I'll see if I can find it.

 

What is everyone's thoughts on the 3.4 w/ a 5spd? Im in the market for a yota and just want to know whats good and what ain't I've heard the 3.4 with a 5spd is the best combo toyota ever made but give me your input! also truck and motor have 187k

 

Honestly count your blessings you get 16.(I say that slightly jokingly.) Mine was getting a solid 13 around town and 15 on the highway before it came out. One of the first things I would check is the condition of your plugs and wires. It might surprise you how much of a difference that plugs and wire can make. The timing AFM and Oxygen sensor can also have a huge impact on mileage and performance. Honestly the 3.0 isn't known for mileage or power either one.

 

Actually, the 4.0 with 6 speed is the best combo they ever made but that's not a viable option in our trucks.