Enhancing 4runner power mpg
#1
Enhancing 4runner power mpg
So i've heard a lot about bigger gears, maf sensors, ISR mods, my question is I have a 94 4runner v6 and i have the 3.90 gears in it ( not 4.10) and from what i'm reading is if I upgrade to say 4.56 or 4.88 it would boost power, and possible to boost mpg a little.
I'm running stock size tires and it is an automatic.
I'm going to be doing a full tuneup soon and swaping in a supra maf sensor as well as doing the ISR mod.
Maybe headers? Maybe not, who knows... and of course the exhaust system upgrade.
I'm currently getting 15.4mpg and I'm a VERY light driver. So assuming I did all of these upgrades, i'm sure I could see a decent increase in power/mpg with my driving style.
However the purpose of this post is to find out would it be a waste to throw some 4.56 or 4.88 on my truck if i'm running stock tire size? Or would it actually be beneficial? Also its a 2wd 4runner.
Thanks for your advise!
I'm running stock size tires and it is an automatic.
I'm going to be doing a full tuneup soon and swaping in a supra maf sensor as well as doing the ISR mod.
Maybe headers? Maybe not, who knows... and of course the exhaust system upgrade.
I'm currently getting 15.4mpg and I'm a VERY light driver. So assuming I did all of these upgrades, i'm sure I could see a decent increase in power/mpg with my driving style.
However the purpose of this post is to find out would it be a waste to throw some 4.56 or 4.88 on my truck if i'm running stock tire size? Or would it actually be beneficial? Also its a 2wd 4runner.
Thanks for your advise!
Last edited by Joe86; 05-01-2012 at 12:11 PM.
#2
Registered User
iTrader: (1)
swap in a 3.4
exhaust is probably the 'best' power mod but still weak.
Alcohol injection helps, I run a 50/50 mix of methanol and dH2O; cleans, lowers emissions, adds power, improves mpgs.... (sorry, I'm just on a mission to promote alky injection, I'm addicted)
this should get you going...
https://www.yotatech.com/forums/f116...r-3vze-220853/
exhaust is probably the 'best' power mod but still weak.
Alcohol injection helps, I run a 50/50 mix of methanol and dH2O; cleans, lowers emissions, adds power, improves mpgs.... (sorry, I'm just on a mission to promote alky injection, I'm addicted)
this should get you going...
https://www.yotatech.com/forums/f116...r-3vze-220853/
#4
Thanks for your reply however that did not answer my question.
My question again is will the 4.56 or 4.88 help the truck or not versus the stock 3.90?
Also i'm not going to do a 3.4 swap in the truck, I just can't fathom the idea of putting over $3k into a truck that is only worth $3k.
I'd rather take the $3k save it and put it towards an actual 3rd gen
My question again is will the 4.56 or 4.88 help the truck or not versus the stock 3.90?
Also i'm not going to do a 3.4 swap in the truck, I just can't fathom the idea of putting over $3k into a truck that is only worth $3k.
I'd rather take the $3k save it and put it towards an actual 3rd gen
#5
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Do you do mostly highway speeds, or in town driving? I ask becuz the shorter gears will def give you a boost in speed (power stays the same), but at highway speeds, the motor will turn higher rpm's, thus netting worse fuel economy. The taller gears may be worse economy for in town driving, but should net better highway speed mpg's.
In all honesty tho... there isnt much you can do to boost your fuel economy, these motors drink like sailors :-)
In all honesty tho... there isnt much you can do to boost your fuel economy, these motors drink like sailors :-)
#6
Do you do mostly highway speeds, or in town driving? I ask becuz the shorter gears will def give you a boost in speed (power stays the same), but at highway speeds, the motor will turn higher rpm's, thus netting worse fuel economy. The taller gears may be worse economy for in town driving, but should net better highway speed mpg's.
In all honesty tho... there isnt much you can do to boost your fuel economy, these motors drink like sailors :-)
In all honesty tho... there isnt much you can do to boost your fuel economy, these motors drink like sailors :-)
In my 87 22re 4runner, I can't drive over 75 because I have 529's and 33's and the engine is just about revving 4k rpm if I go any faster-- my mpg has remained unchanged even with all the extra height and wind resistance. Plus I can accelerate up hills now. The tradeoff in my case was lower top speed. A lot lower.
#7
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Thanks for your reply however that did not answer my question.
My question again is will the 4.56 or 4.88 help the truck or not versus the stock 3.90?
Also i'm not going to do a 3.4 swap in the truck, I just can't fathom the idea of putting over $3k into a truck that is only worth $3k.
I'd rather take the $3k save it and put it towards an actual 3rd gen
My question again is will the 4.56 or 4.88 help the truck or not versus the stock 3.90?
Also i'm not going to do a 3.4 swap in the truck, I just can't fathom the idea of putting over $3k into a truck that is only worth $3k.
I'd rather take the $3k save it and put it towards an actual 3rd gen
I think the best combination is the typical 4.10:1 gears (manual) 4.30:1 gears (auto) with the stock tire size from the factory (225-75R15 i believe).
Be aware that changing gear ratio means the speedo is out of calibration and that will effect your MPG unless you compensate in your calculations at each refuel.
My 91 truck from the factory was getting almost 25MPG with 4.10:1gears/manual trans/stock tires. Moved up to 32x11.50 ATs and lost ~ 3MPG (after corrections to the calculations due to speedo calibration) When I stepped up to 38.5x16 swampers and regeared to 5.29:1, my mileage was down to 18MPG (and this tire/gear combo corrected the offset in the speedo to almost perfect - within 1% accuracy)
The trick is to keep the engine within its optimal power band. Having the engine struggle because its running too low an RPM range or racing because it is running too high an RPM range will hurt fuel economy. Oh and you can hurt mileage running high RPMs since the computer likes to keep the engine at an optimal air/fuel ratio. More air means more fuel consumption. going downhill with your foot out of the skinny pedal means the throttle is closed more meaning less air. the opposite hold true for uphill.
Last edited by cblackard; 05-02-2012 at 09:59 AM. Reason: additional input
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#9
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Um, not exactly. Gas mileage is defined by how much fuel goes into the engine per mile. The RPM's do not predict gas mileage-- injector pulse width does. Think of it this way: If you were going down a hill at 70mph, you would get better mileage because the force of gravity is assisting the engine, thus lowering the injector pulse width and simulating a lighter vehicle. On a flat surface at 70mph, you still have the same rpm, but higher injector pulse width and thus lower mpg.
Going downhill no matter the type of trans, motor, or weight of the vehicle will always drop the RPM. So driving downhill is not the same thing as driving on a flat surface.
I understand what your getting at with injector pulse width, but to say RPM has nothing to do with it is wrong, as you drop RPM's the ECU adjusts the fuel needed (IPW), they are variables that cannot stand alone, one directly effects the other...
#10
Going downhill no matter the type of trans, motor, or weight of the vehicle will always drop the RPM. So driving downhill is not the same thing as driving on a flat surface.
I understand what your getting at with injector pulse width, but to say RPM has nothing to do with it is wrong, as you drop RPM's the ECU adjusts the fuel needed (IPW), they are variables that cannot stand alone, one directly effects the other...
I understand what your getting at with injector pulse width, but to say RPM has nothing to do with it is wrong, as you drop RPM's the ECU adjusts the fuel needed (IPW), they are variables that cannot stand alone, one directly effects the other...
When MPG tests are done in real life, they are done by using a flowmeter which determines EXACTLY how much fuel flows to the engine per second at a specific speed under specific conditions. It doesn't matter what the engine is doing to maintain that speed, it could be 100 rpm or 135,000 rpm, both cases are irrelevant as long as the amount of fuel flowing per second can be measured with the car maintaining a constant speed.
#12
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#16
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^yup, should be in your door. My 5speed '93 runner has 4.56 gears stock with 31" tires, I think the autos came with 4.33? dunno for sure, but 3.90 is pretty bad unless you only do highway driving. I realize it's a 2wd so the gearing is different naturally...
figure out what tire size you wish to run long term and go from there.
http://www.ttora.com/forum/showthread.php?t=56784
there are plenty of tire size rpm/gear calculators and charts floating around, the link here is one of them...
figure out what tire size you wish to run long term and go from there.
http://www.ttora.com/forum/showthread.php?t=56784
there are plenty of tire size rpm/gear calculators and charts floating around, the link here is one of them...
#19
Registered User
For all that, you could take your money for gears, tires, recalibration, etc and put it toward a Prius, put the saved gas mileage money toward the monthly payment....problem solved.
#20
I just got a 91 4runner on 36 swampers and im hitting 13 mpg in town. Im jealous! Just got it so I've yet to swap off the swamps and add exhaust. I've just got an open cat and im in CA hahaha