Best mods to increase Mileage?

Use a dry air filter, keep the carbon trap in there, forget key-cycled FAS, give the computer time to light the cats when you start the engine, and if it's below 50 outside take out the intake elbow.

All other standard mileage tricks apply.

 

I try to not be a dick with my posts but I have to agree with some of the others. If I wanted good mpg's I wouldnt have bought a truck. I have an 09 and get 20 on the highway and 14-16 in town. All I do is go easy on the pedal and have a k&n air filter.

 

I really wanted a V6 Prerunner of 4x4, but seeing what you guys are getting, I'm kinda glad I've just got a little RC Base 2.7 5-lug.
I know if I am towing I'm going to really want that V6, but honestly, my only expected towing is a 16ft flatbed loaded with two quads and two YZs, or if/when we move to Texas, a U-Haul.

 

Maybe you could swith to synthetic fluids, it might help a little

 

While I do like the new generation Tacoma's size and towing capacity, you have to admit that it's really about as big as a full-size half-ton used to be. For instance, with a topper the Tacoma's curb weight is about equal to a 1960s full-size Chevy pickup and its modern 236 hp 4.0 liter V-6 engine is as powerful as a stock 327 V-8. If those old Chevy trucks got 15 miles a gallon you though you were doing just fine.

Edit: Gas was 35 cents a gallon but I was getting $20 for working an 11-hour day too.

 

At least our flag looks a gazillion times better.

 

Just to clarify, I'm not "an idiot who bought a $30k truck without looking at the real life mileage". I did my research, this model was getting 18mpg CITY, I'm get 10.3mpg HIGHWAY with an egg under my foot. Am I justified in posting a MPG thread? Now take your offensive posts back to Facebook where they came from.

 

10.3 highway miles certainly justifies posting in the MPG thread. Trying to find out whats going on.
It almost seems like a potential intake restriction or a tuning issue you have there since you have respectable city mileage. Do you have an illuminated check engine light?

 

I know it has gotten more and more popular over the years. I have a friend who is a mechanic for Subaru and some of their cars offer nitrogen in them and they have to send the tires to Costco b/c they don't have the equipment. I honestly don't know what we charge out here, but I prolly won't get it in the next set I have to purchase. Thanks for info on nitrogen!

 

No there's no indicators lit up on my dash, and it hasn't lost power at all.. I'll try throwing a code reader on this weekend and see if there's anything it's not telling me.

 

It's got a leveling kit and 265/70R17's on it, I'm wondering if the change in the frame angle would affect aerodynamic's enough. The aspiration is clear so there's no restriction there. I've never heard a tacoma before mine, so I don't know if there's supposed to be a kind of ticking noise from the engine when it's idling..?

 

Not to be taken the wrong way, the first thing I'd do is double check your numbers. This takes any error out of the picture.
http://oee.nrcan.gc.ca/transportation/tools/fuel-trip-calculator/fuel-calculator-input.cfm?attr=8

Then, a few questions. Did you just buy the truck used? Whats the maintenance history, specifically spark plugs? If unknown, I'd start there, at least pull and inspect. Check tire pressure as said, if not done already. Clean the MAF with cleaner, but be carefull not to damage it.

When you say highway driving, can I assume longer trips? Short trips in cold weather = horrible milage in mine, it improves hugely in warmer weather and longer trips when the engine runs at operating temp. Check that the thermostat isn't stuck open keeping the engine from warming up, the gauge should read about 1/2 way up. Check for dragging brakes by checking for excessive heat after a longer highway trip. Check for uneven tire wear indicating alignment troubles, that will drag down milage as well.

If nothing shows up there, I'd suspect a primary O2 sensor, but the cost means you don't really just want to throw new ones at it without proper diagnostic testing.

Oh, and a bit of a ticking sound is normal, searching here will bring up LOTS on that.

 

I added a tonneau cover and a K&N drop in filter and it increased over 1 MPG... My intent was to cover things in the bed and add a little HP. I realize it's a truck and I wasn't overly wound up about the gas mileage to begin with but I'm not complaining that it increased MPGs either. Certainly not going to complain that I get further with the same tank of gas than I did before. I suspect that if I put some street tires on, it would improve even more but I will save that for next winter when I move to the snow filled mountains of Colorado.

 

10.3 hwy??? Holy balls! That's 85% load in 6th gear. I accelerate with less than that! Time to start hunting down your friction robbers. It's all a game of how far you can go with everything holding you back and it only takes one greedy player to spoil the party.

The stuff I've done definitely works. Just got 4th tank in a row over 20 mpg, and my 10 tank running average up to 20.4 mpg with today's fill (lifetime now 20.3). It's still in the 20s and low 30s for temperature every morning. Got up to 43F this afternoon, it was nice to go out and feel the sun again for a little while.

Once the dealer is done with my little radio issue that intake elbow is coming right back out. This engine HATES air less than 40F going into it. It's like adding another two cylinders' worth of fuel thirst compared to warmer air.

 

Time to repost this. Intakes don't help mpg, and even completely plugged intakes don't hurt mpg if your vehicle is less than 20 years old. HP yes, MPG no.

http://www.tacomaworld.com/forum/technical-chat/195952-air-filters-mpg.html

I'll go further than Chris and say this study doesn't even show a 1-2% loss in mpg, if anything it could show a trend toward a gain in mpg with a plugged air filter. More study required, Less air =less fuel.

 

Actually the best thing to do to our intakes for mileage is make the airflow over the MAF as smooth as possible. Noisy intakes sound cool but all those unmuffled harmonics going back and forth down the pipe can jack up the readings. It works fine with lots of airflow movement but when it's minimal (cruise conditions) it can confuse the computer and make some really weird stuff happen when waves heading up the pipe interfere with those going back to the engine. If they resonate too much in the MAF the air can be metered multiple times, etc etc.

Carbon trap and dry filters absorb the pressure waves coming up the intake, minimizing the level of waves reflected from the atmosphere end of the intake, and smooth things out down the line. A plugged filter can even muffle it more, not that it's good to run around with one.

Now speed density systems are a different animal. A noisy intake CAN make better mileage on one of those.

 

^ Evidence?.......evidence........evidence......etc.

 

He's getting 20mpg out of a V6 4x4... must be doing something right

 

No doubt with a v6 stick getting 20 takes some skill.

I'm asking for evidence on the "If they resonate too much in the MAF the air can be metered multiple times, etc etc."

and

"Now speed density systems are a different animal. A noisy intake CAN make better mileage on one of those."

and

" A plugged filter can even muffle it more, not that it's good to run around with one."

The evidence I posted say plugged isn't bad for mpg, and the more plugged a filter gets the more dirt it traps. Hardly a bad thing, though certainly HP will drop. The topic is MPG.

 

One of these days I'm gonna figure out what derp means. That word exists not in the north.


Lets see how far my tired brain can compute this evening.

As for evidence, I'm no automotive engineer so I can't give qualitative reports to what I posted, but I can elaborate on the logic of it.

First, basics on the way the MAF sensor operates. As most here know, ours uses a heated wire that the air going through the sensor passes over, the temperature of that wire is measured and regulated by the circuitry in the sensor, and the voltage needed to keep it at that temperature is the info sent to the ECU. It then calculates airflow from that data.

The problem is that it doesn't pass all the air over the wire - that's not practical. The essential part is that the ECU uses known variables to guess what's really going on.

The first thing to consider is the design of it. If you look at the sensor carefully, it holds the meter wires way up inside the tube. The motion of air in the intake pushes it up one side of the meter to the wires and back down again. However, the intake system is hardly a place of smooth airflow. The cycle of the engine inevitably causes pulses (read: start and stop) within the air motion that as long as they interfere with each other in a known manner don't affect the operation of the MAF. When the system is changed in any way, these waves no longer behave in a known fashion, and can cause calibration issues that the ECU will have to compensate for. I believe this is what caused fairly substantial "dead zones" in my truck's acceleration under certain conditions when the carbon trap was first removed that later disappeared. This is what I refer to when I stated it was possible for air to be metered multiple times, or to amend that, also possible for metering to nearly stop and lose accuracy, if the condition exists when the harmonic disruptions within the intake also disrupting flow within the sensor do so in a way not originally programmed to be compensated for.

Under low load conditions the airspeed passing the sensor is far less and it is much more prone to eddies and such interfering with its operation. If you want to test this out for yourself, just pull the air straightener screen in the airbox under the carbon trap and see how poorly the truck drives.

It's going to have interference; the ECU is going to compensate when it happens; however, if you can watch your long term fuel trims (like on a UG) in live time you'd see them changing with minute changes in rpm, much more so with the intake in something other than stock form (just a K&N drop in doubled its typical daily range). When this happens, it means the fuel tables Toyota put in don't match what the o2 sensors are spitting out and it constantly has to change the multipliers. This gives minor inefficiency in throttle tip-in enrichment and the initial fuel delivery at new engine speeds.

If you want to talk aftermarket intakes, an additional concern is whether they matched the diameter of the original tube exactly, but the same calibration issues as above exist.

Next part, skipping to the plugged filter...

Air restriction works both ways across a filter. If it can't get in, it can't get out either. That means it will dampen pressure waves up the intake that reflect back down the tube once they hit the big plenum we call the atmosphere. Ever wonder why a K&N filter "makes" so much noise? It simply lets those pressure waves have all kinds of fun bouncing from one end of the intake system to the other and back again. The more dampening you have, the less this happens, and the fewer inconsistencies in the flow across the MAF you get. Therefore, the more plugged the filter, the quieter the intake, the smoother the airflow.

Back to the second point...

Speed density systems rely on a MAP sensor (and IAT) to determine fuel use. This means the ECU's readings are at the mercy of vacuum fluctuations in the manifold. Stock intakes often have 2 or 3 resonators with at least one in close proximity to the throttle plate to give good throttle response and quiet operation. Two things normally happen when it is changed over to a tube intake: the extra "plenum" on the other side of the throttle plate is gone, and the flow becomes more laminar in the tube. It becomes a long helmholz resonator. On some cars, the tuning of the tube can be beneficial to the point of balancing vacuum across the throttle plate at certain cruising speeds; on others, it does more harm than good if the original intake is well-designed enough or the manifold plenum big enough.

The reverse happens with a shorty stack intake. Even though it is exposed to hot air, a speed density regulated engine with a cone filter on the throttle body often returns worse mileage than with any other type of system.

***

Summary for us, on the stock box, as long as it's relatively unmolested, filter choice and presence (or lack thereof) of the carbon trap should fall within the capability of adjustment of the ECU so mileage difference would be very minimal. Other factors such as resistance to air draw into the engine are so insignificant compared to the energy needed to actually push the truck down the road that they really don't even matter.


edit: remind me not to log in when home sick. Opinionated keyboard diarrhea ensues