Horrible Gas Mileage

[joey3002]

Hoping you guys might be able to give me some advice or next step before I take it to dealer.. My wifes 2006 Xa is getting horrible gas milage. She is getting about 160-170 miles on a full tank. She does manly city driving but still.. I have replaced the plugs (iridiums), oil, oil filter (k&n), air filter, cabin filter, drained 30% of the trans fluid, seafoamed the system first. That is the complete list of everything I have done in the 2 months she has owned it. What else can I do or what else could be driving her mpg so low? thanks

[JIMXB]

Wow that MPG is low about 15 MPG avg.

0.032 gap on the spark plugs?

Improperly aligned or inflated tires can lower fuel economy by increasing rolling resistance. The proper tire pressure for your vehicle is usually found on a sticker in the driver's side door jamb. I use 32 psi on my xB + xA stock tires with no problems.

What motor oil grade are u using?

But, other than this u should not a big difference on MPG.
City MPG is rated at 31 for auto xA with a 11.9 gal. gas tank

This may have nothing to do with MPG. U mentioned you drained the trans 30%. What did u use to fill it back up with??? Cause I have an automatic xB + xA. I had brought my car to a Amcco transmission to change trans fluid in my xB + they said our car use special trans fluid Toyota Type IV ATF that they don't carry + they advise u need the correct fluid not to substitute with anything else + to bring back to the dealer to do correct.
My wife went to a quick oil change place once + they use a generic trans oil on xA which I found out after + had to get it drained out by the dealer + have them fill correctly. I understand that some people have been using Synthetic trans oil Enos or Royal Purple.

Good Luck

[joey3002]

Originally Posted by JIMXB

Is the car automatic or stick?

Improperly aligned or inflated tires can lower fuel economy by increasing rolling resistance. The proper tire pressure for your vehicle is usually found on a sticker in the driver's side door jamb. I use 32 psi on my xB + xA stock tires with no problems.


What motor oil grade are u using?

This may have nothing to do with MPG. U mentioned you drained the trans 30%. What did u use to fill it back up with??? Cause I have an automatic xB + xA. I had brought my car to a Amcco transmission to change trans fluid in my xB + they said our car use special trans fluid Toyota Type IV ATF that they don't carry + they advise u need the correct fluid not to substitute with anything else + to bring back to the dealer to do correct.
My wife went to a quick oil change place once + they use a generic trans oil on xA which I found out after + had to get it drained out by the dealer + have them fill correctly. I understand that some people have been using Synthetic trans oil Enos or Royal Purple.

Good Luck

I will check pressure tonight
5w30
I used normal trans fluid but I did double check the Type.
What is normal for this car? I wanted to update as well.. its a 2006.. sorry about the mixup.

[AnotherDude]

Try a fuel system cleaner, check tires to make sure they're at the correct psi, they still have tread, driving habits are a HUGE factor to MPG also (make sure she is driving it conservatively and keeping the rpms below 3k).

Also, depending on the mileage on the xA, you might need to do some more maintenance work as well.

[joey3002]

Originally Posted by AnotherDude

Try a fuel system cleaner, check tires to make sure they're at the correct psi, they still have tread, driving habits are a HUGE factor to MPG also (make sure she is driving it conservatively and keeping the rpms below 3k).

Also, depending on the mileage on the xA, you might need to do some more maintenance work as well.

What fuel cleaner do you recommend? What other maintenance do you think?

[engifineer]

About the only fuel cleaner that is worth a crap is BG44k. It is the only one my dads shop has ever recommended and the one Toyota dealerships and some others use. The cheap off the shelf stuff at stores does a tiny bit to maybe help keep a clean system clean, but BG's actually does a great job cleaning a dirty system. I have seen great results using it on systems that have been neglected, and typically run it through my cars about every 50,000 miles. Seafoam is ok for bad carbon buildups, but bg is best as a complete cleaner.

I dont see that being your mileage issue though.

Can you swap cars with her for a while to eliminate driver style being the culprit?

My tc has hald a running avg of around 25mpg combined since I bought it in 04. I shift at about 3000 -3500 rpm most times, dont beat on it but dont drive like a granny either. Even after autox test n tunes where it sees 40+ runs near redline it still gets 15-20 mpg. So something else is up on your xa if mileage is super low.

[eboardracer]

normal maintenance, or the lack thereof, should not decrease a nearly 30mpg car down to 15mpg. My advice is that you should probably do a fuel system clean out, make sure your spark plugs are properly gapped, make sure the air filter is clean, and most importantly check you MAF sensor and oxygen sensor.

Just my 2 cents.

[joey3002]

I bought iridiums, they come pre-gapped but I did not double check.. I guess I know what I am doing sunday.

For the MAF... how do I check/clean that? With the O2, is there a way to test them? I am not throwing any codes.

thanks

[JIMXB]

[quote=joey3002;3972693]I bought iridiums, they come pre-gapped but I did not double check.. I guess I know what I am doing sunday.

For the MAF... how do I check/clean that? With the O2, is there a way to test them? I am not throwing any codes.

The iridiums are usually pregap 0.032 or 0.044 on the xA/xB spark plugs depending on the Mfg. part#. Scion recommends .032 gap, but some SL people are using the .044. There are many blogs on this gap size topic for Pro + Cons.

As for checking/cleaning the MAF, there may be pics + instructions on clubxb.com for your easy use. xB engine layout is basically the same as the xA.

How many miles do u have on the xA? Have u ever changed the $6.00 PCV valve?

Good Luck.......

[joey3002]

[quote=JIMXB;3972779]

Originally Posted by joey3002

I bought iridiums, they come pre-gapped but I did not double check.. I guess I know what I am doing sunday.

For the MAF... how do I check/clean that? With the O2, is there a way to test them? I am not throwing any codes.

The iridiums are usually pregap 0.032 or 0.044 on the xA/xB spark plugs depending on the Mfg. part#. Scion recommends .032 gap, but some SL people are using the .044. There are many blogs on this gap size topic for Pro + Cons.

As for checking/cleaning the MAF, there may be pics + instructions on clubxb.com for your easy use. xB engine layout is basically the same as the xA.

How many miles do u have on the xA? Have u ever changed the $6.00 PCV valve?

Good Luck.......

I will do those updates this weekend. As for the PCV, never. It has about 45-50k miles but I have not changed the pcv.. could that be the culprit?

thanks

[dstock1088]

Toyota either has type IV fluid (a universal fluid) or WS (world standard) which is a Toyota specific fluid.

Type IV needs changed every 60k and WS is every 100k

Check your trans dip stick. It will say down towards the end what type of fluid it needs.

Make sure your trans fluid level is correct and DO NOT substitute anything for WS.

:cheers:

[JIMXB]

[quote=joey3002;3973016][quote=JIMXB;3972779]

I will do those updates this weekend. As for the PCV, never. It has about 45-50k miles but I have not changed the pcv.. could that be the culprit?


No, PCV not the major culprit, just aware that u do your own tune up. But, as a preventative maintenace they are usually changed around 50k miles.
http://autos.yahoo.com/maintain/repa...ques079_1.html

Here's the DIY on MAF sensor
http://www.scionlife.com/forums/showthread.php?t=160320

Good Luck......

[joey3002]

Ok, did the MAF and the IAC.. cleaned them both really good. I need to get a new gap tool to check the plugs but for the next day, it will be fine. I will let you guys know.

[RiversideS13]

Have u try to reset the ecu ? Is your check engine light is intact ? What was your spark plugs part number ? Check compression ratio ? Alignment ?
Might be a mess up maf sensor or oxygen sensor

[joey3002]

hmm its getting better.. however, something that I noticed and thought it was due to the car being cold.. i'll explain

I decided to take the car out and give it a quick test.. its about 30 degrees in the northeast (average) so the car was cold when I started it. The blue light on the dash was lit as well. I took it out and at about 40/45 mph, I noticed that it really needed to shift into the last gear, however, it wouldnt. Once I hit about 50, it shifts into the OD. I do notice it shifts easier when its warm than when its warm.

Is this common? I did change out the trans fluid (30%), and last time I checked, it was full. I did use the correct fluid as well.

Thanks again guys.. I really appreciate it.

[MidnightScion]

It is normal for transmission to hold OD until engine is warmed up. Its done to protect transmission form hard use when cold.
On the note of poor MPG, I'd hook it up to scanner and observe pulsewidth of inj, O2 modulation and SHFT LTFT (shot and long fuel trim) ... compare all that to specs.
Also keeping foot off the floor helps. xA isnt particularly powerful, so it is easy to get lower MPG when driven aggressively. When I do trailblazing or mountain driving, I get low -to-mid 20's MPG.

Originally Posted by joey3002

hmm its getting better.. however, something that I noticed and thought it was due to the car being cold.. i'll explain

I decided to take the car out and give it a quick test.. its about 30 degrees in the northeast (average) so the car was cold when I started it. The blue light on the dash was lit as well. I took it out and at about 40/45 mph, I noticed that it really needed to shift into the last gear, however, it wouldnt. Once I hit about 50, it shifts into the OD. I do notice it shifts easier when its warm than when its warm.

Is this common? I did change out the trans fluid (30%), and last time I checked, it was full. I did use the correct fluid as well.

Thanks again guys.. I really appreciate it.

[joey3002]

Originally Posted by MidnightScion

It is normal for transmission to hold OD until engine is warmed up. Its done to protect transmission form hard use when cold.
On the note of poor MPG, I'd hook it up to scanner and observe pulsewidth of inj, O2 modulation and SHFT LTFT (shot and long fuel trim) ... compare all that to specs.
Also keeping foot off the floor helps. xA isnt particularly powerful, so it is easy to get lower MPG when driven aggressively. When I do trailblazing or mountain driving, I get low -to-mid 20's MPG.

Thanks, I have an appointment at the dealership Friday morning.. The car stalled today on my wife while waiting for my son at school. Still no codes though.. Oh and last night I left the negative off the battery to reset the ecu.. plugged it in this morning so that was reset.

[econobox]

Heck, there might even be a fuel leak. Probably it's running too rich for some reason. Faulty 02 sensor? MAF?

[MidnightScion]

Originally Posted by econobox

Heck, there might even be a fuel leak. Probably it's running too rich for some reason. Faulty 02 sensor? MAF?

Vacuum leak?
Does the idle hunt?
Hessitate while accelerate or cruise?