19.8mpg after HC removed! - Page 17 - Toyota Tundra Forums : Tundra Solutions Forum

RONE · #**241** (**permalink**) 07-14-2008, 11:25 AM

Quote:

Originally Posted by cmag1219

took out carbon filter and disconnected negative battery terminal for about 20 minutes. owned truck for a year and never reset ecu. things i've noticed after removal and reset:

1. $75 worth of gas (pump automatically stopped) yields about 18 gallons and "range" read 433 miles until empty. before removal and reset $80 to $90 worth of gas would top off fuel tank and "range" read 341 miles until empty.

2. for first few miles i sand bagged around town and followed slowest moving vehicles for truck to learn granny driving habits and "average" read has been between 18.0mpg and 17.4mpg. before removal and reset "range" read was steady at 15.7mpg after a year without reset.

3. after really getting on the throttle, haven't really noticed quicker throttle response or throaty sound

4. i hit a yellow pole in a parking garage

hope this helps.

D'oh! #4 sucks!

chixdigit · #**242** (**permalink**) 07-14-2008, 04:46 PM

Quote:

Originally Posted by chixdigit

Okay, I am gonna try this mod...
BUT, I am gonna try just re-setting the ECU first to see what that does first. I think I made my truck a gas hog when I first got it by breaking it in by driving it like a bat out of hell. I read Moto-Man's article (link on this site) about running the engine really hard for the first 20-30 miles to "seat the rings" during break-in and I agreed with the logic (and member supporters) so I did it.. After reading ALL of this thread, I think I trained the ECU to suck gas!!! I admit that I am running bigger tires (305/55/20 Toyo A/T's), but I am consistently averaging 12.7mpg!!!
My driving includes heavy rush hour stop n go traffic along a 3 mile parkway twice a day, and then the rest is pretty much highway driving. Again, I admit that I have wider, heavier tires but 12.7mpg!! And THAT is driving 70 on the highway and not really ever punching the gas on starts or passing!
I am going to re-set my ECU tonight and see how my MPG does with my MUCH more reasonable driving than I did when I FIRST got the truck- to break it in.. I will drive it on my daily work commute for a full week, and post how just re-setting the ECU worked for me. I hope (and think) that just doing this will help.
After this week, I will take out the HC filter this weekend, re-set the ECU again, and see how THAT does.
Any other recommendations regarding this mod?

Here is my update so far: (and I haven't even done the mod yet!)
I reset my ECU on Monday evening- July 7th... This is my "baseline" to see if this mod helps MY mileage at all. I am (somewhat) happy to announce that JUST disconnecting my neg battery cable for 20 minutes the re-connecting has changed my avg fuel mileage from the 12.7 that I was very consistently getting to 13.1 at the end of my 250 mile test window. This consisted of Tues-Friday of my normal "work week" driving (outlined above, and Saturday and Sunday of random weekend driving.
Since I never saw true "tankful avg" over 13 prior to this ECU reset, I am convinced that just doing this helped a little already. I am going to use 13.1mpg as my baseline for the HC filter removal, which I will do tonight.
I'll keep you all posted.

Curb71 · #**243** (**permalink**) 07-15-2008, 03:54 AM

Quote:

Originally Posted by HotWheelsUMD

Yes, the TRD CAI does have the HC filter in it. It is very easy to identify and remove. It is inside of the top portion of the intake. It is a flat, white filter. Use a small flat-head screwdriver to pop it out (it is plastic riveted in). Sorry, I did not take pics, but it is very simple. Good luck.

thanks for the info. snapped the frame of the HC filter in two places but got it out atleast.

azmatsci · #**244** (**permalink**) 07-15-2008, 09:41 AM

I can confirm as well. I went from 15.7 to 17.4 with the HC filter removed, trying to be consistant with driving as much as possible. But I will admit when you try to be consistant, you are not being consistant with when you wern't trying, if that makes sense. I then droped in a K&N and reset the ECU and went to 18.4. Then I changed my driving habits and I am up to 19.4 with about 75% highway driving.

Anyway, driving better (keeping under 2k RPM, speed limits or no more than 5 over, etc), and the mods, I will take the 4MPG.

chixdigit · #**245** (**permalink**) 07-15-2008, 05:33 PM

Quote:

Originally Posted by azmatsci

I can confirm as well. I went from 15.7 to 17.4 with the HC filter removed, trying to be consistant with driving as much as possible. But I will admit when you try to be consistant, you are not being consistant with when you wern't trying, if that makes sense. I then droped in a K&N and reset the ECU and went to 18.4. Then I changed my driving habits and I am up to 19.4 with about 75% highway driving.

Anyway, driving better (keeping under 2k RPM, speed limits or no more than 5 over, etc), and the mods, I will take the 4MPG.

Sorry for the stupid question, but is the K&N air filter an "oiled" type filter?

Mr. Creosote · #**246** (**permalink**) 07-15-2008, 08:41 PM

Yes, oiled gauze.

WySilverado · #**247** (**permalink**) 07-16-2008, 01:45 AM

I also did the HC mod but didn't reset the Computer.I'm at 13,000 miles with a K&N drop in since 1000 miles.377.3 miles on 22 gal is 17.5 mpg.Thats from Powell WY (4500ft) to the top of the Big Horn Mtns(close to 9000ft) and back(100 miles round trip).The other 270 miles was to work and back which I usually get 14mpg.I guessed with the 100 mile road trip I'd average out at 16mpg or so.17.5 is insain,only got better than that on two tanks on a Vegas road trip.I just fueled tonight,the next week and a half of normal driving will tell,no road trips,no ecm reset,just the HC mod.My normal tanks of regular driving (around town)are worst of 13 in the winter and best of 14.7 just 2 tanks ago.Best ever was 18.6 hwy.

azmatsci · #**248** (**permalink**) 07-16-2008, 10:02 AM

Quote:

Originally Posted by chixdigit

Sorry for the stupid question, but is the K&N air filter an "oiled" type filter?

Already replied to, but yes it was. I have had good experiences with them on my Explorer. And in the dusty Old Pueblo the dry filters get eaten up quicker.

mr-chessie · #**249** (**permalink**) 07-16-2008, 10:38 AM

after 17 pages, I may have missed it, so please forgive me if I did, but does my '08 4.7 engine have this filter as well?

mxsjw · #**250** (**permalink**) 07-16-2008, 10:43 AM

Quote:

Originally Posted by mr-chessie

after 17 pages, I may have missed it, so please forgive me if I did, but does my '08 4.7 engine have this filter as well?

Yes, and here is a write up in the 1st gen section on how to remove it. How-To: Removing Carbon Filter w/o Damaging It
Should be the same for your 2008.

Badfish · #**251** (**permalink**) 07-16-2008, 11:03 AM

Removed mine and reset the ECU last Friday at 18,415 miles with an average of 15.9 mpg. I'm now at 18,648 and am averaging 17.1. It keeps going up everyday too, yesterday I was at 16.8 mpg when I got home.

DJM86 · #**252** (**permalink**) 07-16-2008, 11:11 AM

Has anyone done a test where they used a device such as a scangauge unit to check the instantaneous mpg prior to removing the HC filter and then checking the instantaneous mpg after removing it under the same conditions to see if it made a difference?

Correct me if I'm wrong, but I thought the mpg reading on the Tundras is an average. So, what you see is averaged from the last time it was reset. And if you reset it now and go and drive on the freeway or attempt to get decent mpg then it should read higher without doing anything. Maybe this has already been said before. Just my $.02.

tacobuilder · #**253** (**permalink**) 07-16-2008, 12:04 PM

Just returned from a 2780 mile round trip Phoenix to Montana, Wyoming, and back. Prior to leaving I did the HC removal. I keep track of all my fuel consumption, hand calculated, and my best to date was 18.1 mpg. On this trip, after the HC removal, my best tank was 20.3, with an overall average of 19.3 mpg for the 2780 miles. Also note that this mileage covered many elevation changes. Throughout the trip I tried to maintain speeds under 70 mph. As an aside, Utah and parts of Idaho sell 85 octane fuel as their low price regular. On this trip, fuel averaged 3.99 to 4.17 per gallon. I used the 85 octane without any obvious issues. I believe the removal of the HC is a positive approach to better fuel economy, it works for me. My truck is 2008,5.7,DC, Zoomers exhaust, ARE cab high shell, with LT tires, total mileage 15313.

MechEng1 · #**254** (**permalink**) 07-16-2008, 01:36 PM

Majority of us here are believers, by just examining how very restrictive the charcoal filter is it will blow your mind away. For anything, I would not put this back until my next smog test. Have fun you guys!!

chixdigit · #**255** (**permalink**) 07-16-2008, 04:42 PM

Quote:

Originally Posted by MechEng1

Majority of us here are believers, by just examining how very restrictive the charcoal filter is it will blow your mind away. For anything, I would not put this back until my next smog test. Have fun you guys!!

I took mine out (gently- w/ out cracking it at all) on Tuesday night and I must have a different version of this filter cause mine did NOT look very restrictive at all... When I held mine up to the setting sun, I could definitley see the charcoal dispersed within the filter, but it seemed like about 50% of the area did NOT have charcoal in there. I could see sunlight right through it.
The charcoal appeared to be pretty thinly spread in my filter... I sure hope it still makes a difference for me!!!
To those that are still considering taking it out, I just used a small bladed flat head screw driver, and gently pried inward RIGHT where the plastic "rivets" were... I pried the ones in the middle of the sides first, then I pried the ones on each corner. If you go slowly, with patience, you should be able to just pry the plastic "rivets" loose without cracking the filter's edges.