plans for spring and summer. goal: more MPG

[bigjv123]

I have an 03 V8 full time 4WD and I do a ton of driving. I'm lucky if I get 310 miles per tank, but from what I've read on here thats pretty normal. I have quite a few mods planned and I'm bored so I wanted to share and get your guys thoughts/suggestions

Synthetic gear oil: I'm going to put it in all 3 diffs...it looks like there are drain and fill plugs on all the diffs, which is awesome. I'm a MOPAR guy and I'm used to having to pop off the cover of the diff in order to change the fluid. If someone could tell me how much fluid goes in each diff that would be great.

Exhaust: first of all I am definitely going to remove the resonator and route the exhaust out the side rather than straight out the back. I'm also going to swap out the muffler probably for a magnaflow or flowmaster. Looks like the piping is 2.5" diameter can anyone confirm this?

Intake: I've seen a lot of options out there for my setup, any suggestions? Looks like there all around $300.

Synthetic Motor Oil: anyone running the 0-30 mobil 1 in this engine? I ran it in my dodge 4.7 V8 (also called for 5-30)

Electric Fan Swap: going to get rid of that god damn clutch fan and put in an electric one. For those of you that have done this...what fan did you use? I'm hoping I can find one that bolts right up with little to no modification. I will go with an aftermarket fan controller to tell the fan when to kick on/off. Any recommendations?

Any other suggestions? I'd love to be able to stretch a tank of gas to 350-375 miles after all this. Just have to wait on some funds.

 

[kkz]

What tires are you using? Judging by your gas mileage, I'd assume you're running somewhat beefy tires, or you have a heavy foot. Doubt you'll get the desired effect from doing what you have planned.

 

[bigjv123]

I'm running BFG Long Trail T/As. they came with the truck (just bought it in January). I definitely have a heavy foot...but I did those exact mods in my 2000 V8 dodge dakota and it netted me about 40-50 more miles per tank, so I'm hoping for the same here.

 

[T4Rforlife]

What size is your fuel tank? I have a 4.0 6cyl that gets me 323 miles one one tank with a 24 gallon fuel tank! So 310 isn't too shabby!

 

[bigjv123]

What size is your fuel tank? I have a 4.0 6cyl that gets me 323 miles one one tank with a 24 gallon fuel tank! So 310 isn't too shabby!

Well when I fill up with the needle resting on E i get about 19-20 gallons.

 

[MICA4R]

Electric Fan Swap: going to get rid of that god damn clutch fan and put in an electric one. For those of you that have done this...what fan did you use? I'm hoping I can find one that bolts right up with little to no modification. I will go with an aftermarket fan controller to tell the fan when to kick on/off. Any recommendations?

That's a new one! Are you trying to eliminate that "roar" on starting the engine?

It is super annoying, I think it wakes up my neighbor every morning.

 

[bigjv123]

That's a new one! Are you trying to eliminate that "roar" on starting the engine?

It is super annoying, I think it wakes up my neighbor every morning.

nope, since the clutch fan is driven by the belt it saps power from the engine. it does it even worse on start up because the fluid in the clutch is settled..thats what makes the roaring sound. granted, it is a VERY tiny amount of power, it will still make something of a difference to remove it and go electric. In my mind any load off the engine is good.

 

[banzaj]

In addition, if not done already, clean the throttle body and MAF sensor, check the alignment even if it's not pulling you right or left, replace the air filter. Check if your brake calipers are ok = wheels should be spinning relatively freely (half-stuck calipers are common on 4Runners). Depending on the mileage, replace the spark plugs - you have iridium ones on V8, they're good for 100K. Sometimes it's a good idea to replace the fuel filter inside the tank, depending on fuel quality and car's mileage. Again, depending on your mileage, you might wanna flush your transmission for the same reasons you're going to switch to synthetic on your engine - new liquid will lube and cool down better, thus causing less resistance.

 

[GMZ]

I have calculated my MPG and I am getting between 19-20.5 mpg consistently with mixed driving. 07 V8 SE 4x4, here are some things which I do to extract maximum efficiency from this beast. Bunch of fancy mods not needed for these results.

-Make sure your tires are inflated properly, all the time, mine are at 35 psi
-Do you carry a lot of crap with you? Toolboxes, bags, crap in the trunk? Get rid of it.
-Tires should be balanced
-Syn fluids might eek out a fraction more mpg but its statistical noise at that point
-Fill up at the same gas station to remove gas quality variables
-Make sure your air filter is not clogged, Im stock fwiw
-Keep your speed under 70, I try and stay around 64 for MPG and police
-Use cruise control!
-Def clean the MAF/TB I did and was surprised how dirty it was
-Since the future is uncertain, I did plugs even though Im only at 50k

The biggest things to take away from this are driving styles and tire pressure.

Ill assume you are referring to the M1 AFE? M1 themselves claim less than $150 saved over 50,000 miles. So right from the horses mouth it is pretty much marketing and a flashy bottle. Also if you look at the numbers between that and regular M1 they arent much different. Pour point and cst are almost the same. I run M1 EP myself.

 

[CAN-03runner]

Synthetic gear oil: I'm going to put it in all 3 diffs...it looks like there are drain and fill plugs on all the diffs, which is awesome. I'm a MOPAR guy and I'm used to having to pop off the cover of the diff in order to change the fluid. If someone could tell me how much fluid goes in each diff that would be great.

Unscrew the fill cap first to make sure you can actually unscrew it to fill it up again. Unscrew the drain plug. Drain fluid. Put drain plug back on. Fill up the diff. Using some kind of oil pump will make it easier. Keep filling until you can see the fluid level with the fill plug hole. It might trickle out a little. When it does, it's full. When the wheels turn and make the diff turn, you might find that you can add a little more. So check it again and top up is needed.

I went the all synthetic route. It did help my mileage. Also changed air filter and cleaned intake manifold and MAS, changed spark plugs and all that jazz etc... Over the past 2 years the mileage is not as good anymore. But I do too many short trips and stop and go traffic. And like someone mentioned already, check the brakes. Right now, I think I adjusted my ebrake too tight a few months ago.

One other thing that I've read about researching exhaust engine codes, is that the O2 sensors on the CATs should be seen as a maintenance item, but most people see them as a replace only when it fails item. They don't just fail but deteriorate. Changing those out could result in a more optimal fuel air mixture.

 

[Gerdo]

Doing everything may squeeze out another 1-2 MPG.

Switching to full synthetic oils will give you the most.

The exhaust, not so much. If you increase the diameter of the tubes, you can loose low end torque so watch that.

The intake will do almost nothing. The throttle body and the tubes feeding it should be the same size from the factory (3rd gens, the tubes are bigger than the TB).

Electric fan, the 3rd gen'ers that have done have noticed little to no increase.

Watch the right foot and loose weight out of the rig.

 

[EDness]

I mean are you trying to save $$$ on gas? Spending all that $$$ just to save 1 mpg? Is it worth it?

The best way to save gas is to lose weight in your belly. Car will be carrying less weight! =p

 

[Eastcoastrunner]

to the above poster, cruise control will NOT increase mpg, it will make it worse, if there are any hills on your commute

 

[ofcbarbrady]

Good luck.........I can barely squeeze 300 out of mine. I'm sure the tires/lift have to a lot to do with it since I was doing 360+ before. But the way I figure it now, I fill it up when it needs it. Can't worry about mpgs anymore, 'cause it's a keeper.

 

[snowbrdr033]

Could also try putting some Lucas brand injector cleaner in your next tank of gas, it helps clean things out and keep it running smoothly. I do one every oil change....plus it's not too expensive, either.