Have you tried cleaning the MAF with some spray electronics cleaner?

 

I have a Gibson exhaust and KN intake on my 4.0 DC and ive noticed the same things, HP go up and gas mileage go down. I expected this though. Theres no way that gaining HP is gona improve gas mileage or stay the same. You are using more fuel now to the more air being sucked in with the intake. I just didnt think it was feasible to get better gas mileage while gaining more power. I too am averaging like 14 mpg on my 6spd,and 16-17 on hwy. all with AC on though.

 

WOW thats really poor i have the K/N and magna flow exhaust i get 19mpg. Never have i got 12mpg eeek that sucks man. When i installed the K/N i didnt unplug my battery. I drive heavy too. 75-80. Would suck if you have to take to the dealer theyll bitch about the intake. Hope you get this fixed. You have the AFE intake havent seen that post pics...

 

I have a K&N off-road intake, magna flow catback. Started off driving cheapest 87 oct in town. If I pushed it, I could drain a tank in a few hours. Switched to 93 for a few weeks then down to 89 with a light foot I can make a tank last a week. Keep your rpms below 2.5 when driving in traffic and 3 everywhere else when passing and mpg will go up.

 

According to consumer reports. nothing will improve your gas milage except driving habits. Not me, consumer reports.

 

I have a Gibson exhaust and KN intake on my 4.0 DC and ive noticed the same things, HP go up and gas mileage go down. I expected this though. Theres no way that gaining HP is gona improve gas mileage or stay the same. You are using more fuel now to the more air being sucked in with the intake. I just didnt think it was feasible to get better gas mileage while gaining more power. I too am averaging like 14 mpg on my 6spd,and 16-17 on hwy. all with AC on though.

All these performance upgrades should atleast maintain/help with mpg- as what Gadget from URD said, we should check out our Mass Air Flow Sensor. Aftermarket intakes do differ from the stock intakes- they don't actually duplicate the flow where the MAF Sensor was installed in. Yes, we're getting more hp but it's because of more efficient burning of gas and fuel. Why is everybody else is getting better mileage than us?

Afe link: http://www.afefilters.com/54-10592%20Toyota%20Tacoma%20Review.htm

 

WOW thats really poor i have the K/N and magna flow exhaust i get 19mpg. Never have i got 12mpg eeek that sucks man. When i installed the K/N i didnt unplug my battery. I drive heavy too. 75-80. Would suck if you have to take to the dealer theyll bitch about the intake. Hope you get this fixed. You have the AFE intake havent seen that post pics...

Definitely worth the money.... After I installed this, it was a definite 10(atleast)hp upgrade! this link actually what pushed me to buy it...http://www.afefilters.com/54-10592%20Toyota%20Tacoma%20Review.htm

 

It's already been said. If you expect better perforance there is a price to pay. There is always a trade-off.

12 mpg is quite low though. Maybe you got some bad gas. Maybe you need an oil change. Maybe your MAF is coated with oil. Maybe you drive your truck like a race car. Point is, there are WAY too many variables as to why your mpg sucks.

It drives me crazy everytime someone starts a "what kind of mpg are you getting?" There are 19 different configurations with thousands of different driving styles. Add in some mods in the mix and forget about it.

Modding is great but it sucks when you have to troubleshoot.

Only you are going to figure this out. All I can suggest is:
1) Clean your MAF with some CRC Electronics Cleaner.
2) Get some Chevron Techron, Gumout Regane or Redline SL-1 injector cleaner.
3) Change your oil if you think it may need it.
4) Unplug your battery for 20+ minutes. Drive normally for a week or two.

These are all simple cheap things to try, if it doesn't improve in two weeks:
1) Replace or clean intake filter.
2) Replace intake with stock box. It ain't working for you. Is a questionable 3-5HP worth a loss in about 5 mpg / 100 miles per tank / and an extra $25 per tank?

 

^ well said


I laughed when I saw "19 hp gain"

 

wow sounds good 19hps though hard to beleive. There isnt much difference from that and the KN. Only the fact that its closed. Sucks that your getting that low of mpg's thought. Hope its the MAF sensor. Good luck.

 

WOW. This is one giant piece of fluff marketing. Where did they get these baseline HP numbers? I certainly hope you are getting more than 160HP to the wheels after you installed that intake.

This isn't even the right engine that they dynoed. It can't be. (edit: I see that they are taking their measurements at 3300 rpms. How can this be accurate? Not even K&N is greedy enough to boast 19 HP gain.)

 

My MAF sensor is clean, already checked it. I only use Chevron or Shell 93 octane and I just got an oil change about 3 weeks ago and I am driving "normal" again. At first, when I just got the intake and exhaust installed, yes- I was rev and gas pedal happy- I'm over it now cause I realized the impact on my mpg. There has got to be something wrong and I'm on a mission to find out what....I'm happy with the performance gains but dang, atleast it should stay the same if I'm driving normal (12-13 mpg just plain sucks!), don't you think?

 

I'm on my 2nd tank with the Gibson catback installed. Bought gas at a different station but other than that my driving habits are the same as always 70-75 on the highway usually. Previously my mpg was around 17.4-17.9 most of the time. At the end of my 2nd tank after installing the Gibson this tank for some reason produced 19.6 mpg. Went back and filled up today at the same place and will see how it goes on this tank!

 

I'm on my 2nd tank with the Gibson catback installed. Bought gas at a different station but other than that my driving habits are the same as always 70-75 on the highway usually. Previously my mpg was around 17.4-17.9 most of the time. At the end of my 2nd tank after installing the Gibson this tank for some reason produced 19.6 mpg. Went back and filled up today at the same place and will see how it goes on this tank!

I'll agree on the highway increase with a cat back exhaust. While I have the TRD exhaust, my mileage stayed exactly the same except one area. Interstate speeds, crusing around 2500+rpm with 6 spd (higher reving than auto 5 spd) has gone up at least 1 mpg. I still get best mileage in the low 2K rpm area (unchanged with exhaust).

Our two examples are two different catbacks, with similar reaults. I wouldnt think the Mangaflow would be much different. Gotta be with that intake somewhere...or the combination. good luck

 

Ok most of you guys have exhaust and intake, but what engine size and transmission do you have? Seems like the autos get better mpg than manuals, and of course the 2.7s get like 20 mpg. Thats understandable.

But u guys getting 18-20, do you have 4.0s and a 6spd w/intake/exhaust.....if u do and get great mpg then im gona have to ask toyota to check out why im not getting that.

 

Ok most of you guys have exhaust and intake, but what engine size and transmission do you have? Seems like the autos get better mpg than manuals, and of course the 2.7s get like 20 mpg. Thats understandable.

But u guys getting 18-20, do you have 4.0s and a 6spd w/intake/exhaust.....if u do and get great mpg then im gona have to ask toyota to check out why im not getting that.

there are WAY too many variables as to why your mpg sucks.

It drives me crazy everytime someone starts a "what kind of mpg are you getting?" There are 19 different configurations with thousands of different driving styles. Add in some mods in the mix and forget about it.

I went to the doctor the other day and asked why I wasn't as big as Lexington Steele.

 

K & N Engineering Inc.
Run Title: Stock 2005 Tacoma 4.0L 4x4 5spd 4g
Run Notes: Stock Baseline Run. 6789 miles. 4th gear run.
Run Date: 3/22/2005 12:10:18 PM
Stock.001: 73.25 °F, 29.09 in-Hg, SAE: 1.01
Run Title: K&N Intake Kit 2005 Tacoma 4.0L 4x4 5spd 4g
Run Notes: K&N Intake Kit installed. 6789 miles. 4th gear run.
Run Date: 3/22/2005 1:41:07 PM
FIPK.002: 74.05 °F, 29.05 in-Hg, SAE: 1.02
399025
10.31hp @ 4978rpm

http://www.kandn.com/dynocharts/63-9025.pdf

I have the 4.0 i get roughly 350 miles to a full tank running beyond the dummy light. 18mpg

Pennzoil Platinum synthetic oil
265/70R17 no lift
K/N intake magna flow exhuast.
Automatic
Going 70-80mph

 

K & N Engineering Inc.
Run Title: Stock 2005 Tacoma 4.0L 4x4 5spd 4g
Run Notes: Stock Baseline Run. 6789 miles. 4th gear run.
Run Date: 3/22/2005 12:10:18 PM
Stock.001: 73.25 °F, 29.09 in-Hg, SAE: 1.01
Run Title: K&N Intake Kit 2005 Tacoma 4.0L 4x4 5spd 4g
Run Notes: K&N Intake Kit installed. 6789 miles. 4th gear run.
Run Date: 3/22/2005 1:41:07 PM
FIPK.002: 74.05 °F, 29.05 in-Hg, SAE: 1.02
399025
10.31hp @ 4978rpm

http://www.kandn.com/dynocharts/63-9025.pdf

I have the 4.0 i get roughly 350 miles to a full tank running beyond the dummy light. 18mpg

Pennzoil Platinum synthetic oil
265/70R17 no lift
K/N intake magna flow exhuast.
Automatic
Going 70-80mph

 

Whats that for Boone?

 

I wasnt going to bother saying it but Ill try anyway. Everyone on this forum has different driving styles. Everyone on this forum drives on different roads and highways. That accounts for most of the difference in gas mileage that everyone gets, IMO.

 

Thats very true no one is saying anything wrong here, its just awkard to get 12mpg. Were just trying to help of course if you drive your tacoma like a dam Lambo then your going to get bad gas mileage.

 

12 mpg does suck Id say youve got something screwy there. I dont think the intake would make that much difference.

 

Do you really have to unplug the battery for 20minutes? Proof?

 

yeah i didnt unplug my battery at all.......

 

My Engine check light came on, the next day. When i installed my intake... I need to turn it off.