Mpg seems very low

[unko]

Just picked up a 1997 4runner with the 5vz with 160000 miles. It's a 5speed 4wd with roof racks.
I already changed the oil and filter, aswell as air filter a new clutch master and trans and diff fluid. Cleaned the throttle body it was pretty gunky and I already seafoam the motor thru the vacuum method

My mpg seems very low, I think I'm averaging any where from 14 to 17 mpg.
If I fill her up all the way (chevron) by half tank I only put on 100 miles, and gas prices in hawaii sucks bad. With my last fill up I also added a bottle of techron fuel injector cleaner.

Anyone else getting the same mileage as me?
Is there anything I could do to enhance my mpg? Would new plugs and wires help?
Also I think It maybe slowly burning some oil, lately I've been having to add everytime I check the dipstick it's a little lower than full. Looked underneath and it's as dry as a desert. I never heard of anyone's 5vz leaking or burning oil I know it's pretty rare. My last change I dumped a whole quart of Lucus oil stabilizer and napa 5w-30. If I need a thicker oil which viscosity should I go with?

Thanks in advance, sorry for the scroll.

 

[02SE]

I have a '97 4WD V6 5 speed with the larger optional tires, which I bought new off the lot in '97. They were rated at 15 MPG city, 19 MPG highway.

I'd say you're in the ballpark for expected MPG.

 

[TastyRunner]

That is exactly what I get and my t4r is a 2001 sr5. The best I have gotten is 18. I think I am on my original spark plugs too so I am going to do some routine maintenance soon.

Try the deckplate mod. I am going to soon!

 

[unko]

Ok I feel a little better lol. Well it does help to know I'm not the only one suffering with mpg. But I really love the truck and I this is my first v6 so I guess it's all new to me. I do plan on changing plugs and wires soon thou, I will be buying oem toyota replacement parts for both. I looking for a solution to combat my low mpg still thou, and that deck plate mod does seem like a cool weekend project with some good benefits.

The truck runs great but there is a few things I need to address, sway bar end links up front is fully separated, brake rotors are warped some I guess due to the shaking of the wheel during hard deceleration, but all in all a happy and healthy 17 year old truck.

Before buying a 3rd gen I was really set on one because I knew these 3.4 will last for many many miles, nothing but good reviews on these motors. Can't wait to get a lift and some tires.

Here's how she sits as of now

Thanks for the replies guys, helped in assuring my mpg is fine.

 

[eatmorechickenx]

Drive VERY easy and dont go over 65. With 32 duratracs, I get just under 24 mpg with cruise on 50, 22 on 55-60, 20 at 65, and 16-17 over 70. Just a little testing for u guys. By the way these these numbers are spot on. Accurate odometer thoroughly tested with gps. Depending on how easily I launch from lights I range anywhere from 14-19 mpg. Its in how you drive it. Its an suv not a sports car.

 

[eatmorechickenx]

By the way, mine also just turned 300k yesterday and has low compression on one cylinder just for some perspective.

 

[Arnezie]

18.5 average on my 2000 auto Trans

 

[Kryptoroxx]

Nice rig! Hope it gives you, any years of service.

Just as a suggestion and if you feel like doing it you could check your valves. I was getting the same numbers as you were with a 3rz and I changed all but 5 of my valve shims. Now I am back in the 20s where I should be. I know the 5vz is a little more pita than the 3rz though (more valves and less room). This cam be expensive as the shims are like 8 bucks a pop and you habe to attain a special 50 dollar tool. Mine worked out to 150 or so but it beat the stealership by a lot

Another little culprit easily fixed is your vacuum lines. You can use oem or silicone but cracked vacuum lines cam create a little leak and throw you off a little. Cheap replacement. I did mine for 35 bucks.

Tires can be a mpg gobbler if they are heavy or oversized.

Seafoam can help clean stuff up if you put some in the gas tank and some in the crankcase (about 500mi before an oil change). Your oil will be midnight black I assure you. You can also put it through a vacuum line and clean your valves up a bit. Suck in a quarter can and then shut it off for 5 min. Turn it back on and let it idle till the white smoke stops. I would recommend not doing this at home if your neighbors are touchy. It will smoke for about 10-15 min depending on how dirty it is.

You can also clean your throttle body as well as your intake manifold pleniums. Make sure you use throttle body cleaner and not carb cleaner. Big difference and you will destroy your throttle body.

The biggest one though like mentioned above is how you drive.

 

[Nunyabiz]

3rd gens apparently just suck MPG wise compared to newer engines.
I wouldn't expect too much better mpg no matter what you do.

I would however change your oil to a quality synthetic like a 5W30 Amsoil.
That "may" help your oil situation OR if you have an actual leak from dried out seals it might show you where that problem is when it cleans out the gunk.
Also make sure you replace the PCV VALVE this could be your oil problem.

Do a compression check

About the only way you might see a slight improvement in mpg IF everything else is fine such as change plugs and wires, 02 sensors, etc is to get it breathing better by doing the deckplate mod PLUS changing out the stock intake to an AirRaid to delete the silencer PLUS replacing the stock muffler with a better flowing one.
This could possibly net you as much as 2mpg on highway probably less than 1mpg city.
Since you are on an island I assume that most of your driving is fairly short trips, lots of stops and up and down hills so if that is true then you may see zero improvement mileage wise.
I only average about 13mpg 100% city, short trips, stop N go, hills.
But have seen over 21mpg 100% highway after changing out the intake and muffler.

 

[TastyRunner]

I live in the Phoenix area so going 65 on the highway is a death sentence. LOL. I average 70-75 and still get around 17 or 18 tops, plus it has been windy here so far this spring/ summer.

 

[CallMeAnEngineer]

Sounds pretty normal

 

[jgue467]

Drive VERY easy and dont go over 65.... Its in how you drive it. Its an suv not a sports car.

My Porsche only gets 18 (3.2 boxer 6 cyl) in mixed driving, my runner (5vz) gets 18+ in mixed driving (16 city/20 hwy)! Go figure! :banana:

 

[unko]

Wow thanks for the positive comments and some great advice on maintenance I should do.
Hearing from you guys I think a lot of it has to do with my driving habit, I am a bit of a lead foot, coming off a
red light I like smashing the skinny pedal and I like to be around 70mph a lot lol. My last 5speed car was an integra so blame the little kid in me.

Well looks like I will be doing a seafoam treatment to the gas and oil my next change. But I got a lot of great ideas on what I could possibly change, like vacuum lines, check compression, valves and what not. I also plan on cleaning the throttle body again and maf as well.

But the ISR and deckplate mod seems like a great start, just need to save up some clams to do the exhaust. Would replacing just the exhaust can with stock piping be a bad idea?

 

[ARC]

Unko what island are you on? What kind if driving are you doing? If you are commuting in stop and go everyday on the H1 then I say you are doing pretty good. But sea foam is known to destroy plugs so I would do that ASAP.

I got 25mpg out of my 5 speed prior to lifting and now get about 20mpg. Although it is hard to know since usually there is lots of hard wheeling in between fill ups now. My point being you should be able to see low 20's no problem depending on driving style and traffic. Though I generally get better Mpg out of vehicles than most people. I average 21mpg in my Daily Driver 5.7 liter Tundra.

My 4runner has no mods to improve gas mileage and has 24x,xxx miles on it.

 

[unko]

I'm located on oahu, and yes it being an island I do a lot of city stop and go traffic. I'm starting to feel its all about my driving habit, and conditions.

Yeah I've heard about seafoam fouling plugs but it hasn't ever happened to me. I might let the motor suck up some washer fluid to give the internals a nice steam clean and see what effect that has on my beast of a motor lol.

 

[piecesparts]

My 97 was getting a steady 17 to 17.5 MPG driving back and forth to work. I just recently changed the muffler out for a Magnaflow and now the MPG is steady at 18.5 MPG, and to top it off, it runs better on the highway.

 

[unko]

After getting an alarm with remote start I plan on buying an exhaust. With my minitruck toyotas I would always get a flowmaster, mainly for the sound but I don't think it's much of a performance exhaust. I've never had any other exhaust, what's a good exhaust to accompany our motors? I heard borla is good for toyota, and magma flow just seems to universals for an exhaust but I could be wrong.

 

[98WhiteT4R]

I get 16 combined which isn't too bad with 33s

 

[drdolittlerwc]

My mpg seems very low, I think I'm averaging any where from 14 to 17 mpg.
If I fill her up all the way (chevron) by half tank I only put on 100 miles, and gas prices in hawaii sucks bad. With my last fill up I also added a bottle of techron fuel injector cleaner.

Anyone else getting the same mileage as me?

Not sure if anyone mentioned yet, but the fuel gauge on the 3rd gen is a little on the faulty side. I couldn't believe it myself when I first saw mine drop that quickly (90-100 miles in half a tank), thought I was driving a 454, but the needle slows after that and REALLY creeps.

Then I started figuring my mileage was 16-17mpg (standard combo city/highway). Then we drove 34k to Belize from San Francisco and my mileage jumped to approx. 20mpg (60-65mph on cruise control). The computer is always 'learning' and will adapt to your driving.

Not sure about gas prices in Hawaii, but here in Belize it's almost $6us/gal. I recently switched to butane/propane @ $2.35/gal. My mpg dropped but my savings remained. Before I was paying approx. $0.77/mile now it's $0.38/mile. HUGE!!

Still totally happy to have it here! And MANY are asking to buy it!

 

[Lavender Steel]

Not sure if anyone mentioned yet, but the fuel gauge on the 3rd gen is a little on the faulty side. I couldn't believe it myself when I first saw mine drop that quickly (90-100 miles in half a tank), thought I was driving a 454, but the needle slows after that and REALLY creeps.

I've noticed this as well, my friend's 4th gen is the same way.

Has anyone pulled a gas tank and taken pictures? I'm curious if the tank has a uniform cross-section throughout it's height? Does it sit level?

The fuel gauge works off a float, correct? So it's not measuring volume - just the fuel level.... this could cause the inconsistent rate of change.