Newby MPG Questions (Look out!)

[Yaryaryaris]

Hi everyone,

I'm a long time MPG-head (metro Xfi's, festivas, tercels, echos, etc.) recently got a good deal on what was my modest dream car (07 Yaris HB 5-spd) only options: A/C and cruise. I NEVER use the A/C (I wouldn't use it on the surface of the son, just out of principle)...

Anyway, I got it used with approx. 35K The only "mod" it came with is a K&N air intake (it was a surprise, not told to me until I flew from Mn. to Utah to fetch the car) I figured it wouldn't hurt MPG's, and might even help.

On my way back to Mn. I drove exactly 57MPH with one other person in the car and averaged around 39MPG.

I found this VERY disappointing considering my Echo (2-dr, 5-spd) got 50+MPG's driven this way (I never got less than 45MPG with that car)

But wait, it gets worse. I realize it's winter (and Mn. has plenty of it) but I can't get this car to get anything over 35MPG NO MATTER HOW EASY I DRIVE!!! Sure, I could push it around with the engine off.

I'm an experienced max-mpg driver, never speed, slow take-offs, low RPM's coasting when possible, etc.

My research regarding this so far has been that the relevant differences between the Echo and Yaris are: weight (Yaris is heavier) wheels (Yaris' are bigger and wider) and shape (I've read the HB has more drag than the sedan)

But I've been reading here on this forum (and other accounts elsewhere) of people getting much better MPG's with my exact Yaris, and even AT models.

Questions: Could the K&N filter be negatively effecting MPG's

I also run my tires at 44PSI (yeap, it's a rough ride, but I'm all about the MPG's)

Any advice would be much appreciated. I put in a request for the stock intake available over on the FS section BTW.

Brenton

[BailOut]

Welcome to the Yaris family, Brenton!

It sounds to me like the previous owner drove the car rather hard. The Yaris' ECU "learns" one's driving style and will run richer or leaner accordingly.

Try pulling the ECU fuse in the block under the hood for 15 minutes to reset it, and then give it a few weeks to adapt to your hypermiling style.

[Yaris Hilton]

I've seen reports of over-oiled K&N filters coating the mass airflow sensors with oil and messing up the mixture. Can't hurt to clean it. There's a thread on here somewhere on doing that. You should be getting better mileage cruising like that.

[TLyttle]

I ain't supposed to say this, but I have had less-than-stellar performance from K&N filters. Previous vehicles often suffered after the K&N installation, rectified by modifying the vehicle to take a larger paper filter. Sometimes this is not possible (my Volvo 245 is next), but a little bit of backyard engineering is all that it takes to make a decent (in one case, 10%) difference to fuel mileage, without damaging performance...

[Yaryaryaris]

I went out tonight and pulled two small fuses. If I'm readin the back of the lid correctly, the ECU is the small 15 amp about half way down the line? I also pulled the 7.5 next to it in case I'm reading it wrong.

Thanks for that advice, it's very possible (likely) the former owner didn't care as much about MPG's as I do, and thus drove it "normal"

And thanks for the welcome. I'll be here a lot.

Brenton

[Yaryaryaris]

Another Quick Question: Since the Echo and Yaris use the same drive train (as far I know) might the echo have a taller final drive ratio in the manual trans? It was like this with the metros (XFi trans runs lower RPMs at cruise, increasing the MPG's dramatically)

Just curious. I would switch mine out if it was the case.

Brenton

[jambo101]

If you have your heater controls in the defrost range the air conditioner continually cycles on and off,may not make much of a difference but that combined with other factors such as oil viscosity,engine tune,tires rolling resistance can all add up to lost efficiency,my scan gauge gives me a reading in the mid 40's when doing long trips at steady highway speeds in my 08 Yaris sedan and readings in the high 40's in my 05 Echo sedan. I'd go back to stock air filter as the onboard computer may be misreading something in the filters parameters and using more gas to compensate (just a guess)
There are also some forums that take fuel efficiency to whole new levels,give em a try.
example=http://www.cleanmpg.com/forums/

[Yaris Hilton]

You don't need to pull any fuses or reset the ECU. The adaptive learning goes on all the time, and it will adjust to your driving very quickly. It doesn't affect mixture anyway, mostly transmission shift points.

[b_hickman11]

Does the AC compressor have it's own fuse? If so maybe you could just pull it? Not for sure if everything else would still work though.

[Yaryaryaris]

Originally Posted by b_hickman11

Does the AC compressor have it's own fuse? If so maybe you could just pull it? Not for sure if everything else would still work though.

If someone knows the answer to this, and where it's located, I'll try it.

Thanks,
Brenton

[Astroman]

Someone did find the part number for a belt designed for our engines without AC. The defrost should work w/o the AC, but slower. Having the AC linked up clears the windows up almost instantly.

[Yaryaryaris]

Here's a pic of the K&N unit:

http://www.flickr.com/photos/40581861@N03/4192984839/

There's no filth or oil anywhere that I can see. The little black boxy unit with wires coming off it (MAS?) rests a little lose on the silver tube, and air probably can slip underneath it. A possible issue?

Brenton

[jambo101]

An informative previous topic on AC and the defrost and a tutorial in the first post on how to bypass the system.
http://www.yarisworld.com/forums/sho...hlight=defrost

[jonismyname]

just found this thread after pming yar yar yaris everything already posted. sorry dude. looking at the picture, that's not a kn air intake, probably an ebay critter, and probably improperly installed. the MAF would def be a concern. google "clean MAF" or something along those lines. like i said in PM, CRC (chemical company) makes a MAF cleaner that is safe to hose it down with. NAPA sells it.

for the AC, you can unplug the wire going to the electronic clutch, which will not allow it to engage. this will only spin the outer pulley on the compressor, which is very light. just cover things up if you leave it unplugged, or use a fair bit of dielectric grease. something.

[Yaryaryaris]

Jon, thank you for the info both here and PM's.

Question: Is the stock Echo intake the same as the Yaris? I'm sure I can find a wrecked Echo easier than a Yaris (Cheaper too)

I'm in the market for a stock intake anyone.

Thanks everyone else as well.

Brenton

[Yaryaryaris]

I recieved this reply for my WTB Air intake:

What type of Yaris do you have .[/QUOTE]

Response:

Hi, Great! 2007 HB 5-spd.

How much and when can you ship it?

Brenton

But an error pops up "LA Yaris won't allow PM's"

Can anyone contact him/her and say I'll take it?

Thanks

[chew246214]

Larger then stock tires will effect your MPG not questions, Also I have noticed I have put on Michelin X ice snow tires and filled up the tank at the same time... Before with the crappy stock goodyears (BTW are scary in the snow) was an average of 44.9 MPG... Now instantly with the snows down to 38.2 MPG...on the same daily roads. They stick a lot more to the road, Have a lot more surface area (siping) and weigh more, oh I also forgot to mention the wonderful hum that goes along with them as the road surfaces change. I am not concerned with the mile decrease for the few months a year I will be riding on them.. My concern was sliding off the road at 2 miles per hour while trying to turn..... Tires can make all the difference in the world..... Forgot to mention some areas of the country also use different gas mixtures for different times of the year that also makes a difference... Just my experience

[Yaryaryaris]

Okay, so far no luck finding a stock air box (here or elsewhere) a few on car-part.com, but wanting $350 bucks (I was afraid of that) I bought my Yaris HB off eBay, flew to Utah to fetch it, show up, walk around (looks great) pop the hood "what's that?" oh, after market air filter, wife through away the stock one"--not good.

I'm convinced it's "working against me" (as Jon put it) in the MPG's department. The MAS doesn't even rest snug on it's port (was being held on by one screw!) I'm monkeying with that, but much prefer a stock air box (not a modder)

Question: Can someone point me in the direction of where all the hoses attach onto an after-market intake? I'm also guessing mine is hooked up wrong.

Still teased out 41 MPG's yesterday on a 500 mile trip.

Thanks,
Brenton