Regaining lost MPGs

[DaleJrDolphins]

Hello! I have always calculated my MPG at fillups and it seems that even my highway/long trip MPGs have declined. I have always taken great care of this vehicle and it now has 82k miles on it. Ive always used ful synthetic 5w-20, have always cycled through adding injector and carb cleaner/injector cleaner/ complete fuel system cleaner every other fillup, I change my air filter every spring, keep good check on my tire pressures, have already serviced my radiator, changed the plugs, and just yesterday did an entire brake job.....WHERE SHOULD I BE LOOKING NEXT? I used to get like 40.5-42mpg on long trips traveling about 5-10 mph over the limit (limits being 55-75mph depending on state) now it seems that number is down to about 36mpg.
The question is....WHERE SHOULD I BE LOOKING NEXT OR WHAT AREAS DO I STILL NEED TO PERFORM MAINTENANCE in order to keep this car as close to new as i can?
Thank you

[WeeYari]

Same here. I'm tracking about 7% worse over last year. No changes to maintenance, setup, or driving habits.

I'll be watching this thread.

[suckerface]

Have you tried a MAF cleaner? It could be dirty, and not reading air flow properly, and injecting more (?) gas as a result. You can pick up a can of cleaner at any auto parts store for under $10. Check out http://www.microimageonline.com/foru...ir-flow-sensor for a DIY guide.

[WeeYari]

^ yes.

[NEexpat]

^+1 suckerface

Yup, I was thinking that as well.

WeeYari, have you looked at yours?

[barryware]

70 mph seems to be the "wall" on my yaris. Anything over that, my mpg drops substantially.

Have your alignment checked. If the tires are not all pointing in the right direction, they are fighting each other and will also make your mpg decrease.

A few months ago.. I was driving a 400 mile trip. One pit stop, I felt each tire and the left rear was a lot warmer than the right rear. Had an alignment done and that increased my mpg (highway) by 2 ~ 3+

[DaleJrDolphins]

Thank you barryware. I will have that checked. I was thinking that the more likely case was the cat conv and muffler getting older and blocked up but didnt want to lead the conversation down a road intentionally....wanted to see where it went naturally.
In the case of the tires though...i have been watching for even wear and it "seems" that they are wearing evenly. The other thing that made me thing exhaust system was the somewhat small shuttering with the engine/exhaust that I hear/feel....but thats mostly when its colder outside. Any thoughts to that?

[DaleJrDolphins]

im a pretty smart and capable guy...but I never knew to clean the MAFS like this! i just youtubed it, how easy!! Damn...learn something new everyday!
Thanks again....even if this isnt the problem I am gonna clean it anyway!
: )

[barryware]

Originally Posted by DaleJrDolphins

<snip>
In the case of the tires though...i have been watching for even wear and it "seems" that they are wearing evenly. <snip>

Unless your alignment is really out, you won't really see it in the tires if you rotate them often with a light car like the Yaris. I rotate my tires every 7500 miles.

My steering wheel was straight and the cars handling was tight. When I felt the tires with my hand (after a couple hundred miles down the highway), one was much warmer than the others..

The fronts were warmer than the rears (as expected) but the fronts seemed equal in temp. The rears were not equal.

That could also be the result of diff tire pressure but when ever I set out on a few hundred mile journey among other things, I always check the tire pressure so that should not be an issue.

[marcus]

i get about the same from 5 years back just had to baby the car... also about 2 years back i went to toyota seems like they may have flashed my ecu which totally change the gas meter bar where it falls off on per bar basis..

[DaleJrDolphins]

so no concern about the exhaust system yet???

in a semi related topic....I am really trying to get maximum economy first, but also maximum performance as long as its not at the cost of economy....any thoughts on high performance air filters?

Thanks again

[bobolinko]

Originally Posted by DaleJrDolphins

The question is....WHERE SHOULD I BE LOOKING NEXT OR WHAT AREAS DO I STILL NEED TO PERFORM MAINTENANCE in order to keep this car as close to new as i can?
Thank you

I, too have noticed a BIG drop in my mileage. Mine is only 30K mi, and I had a drop from 42 to 27! It was a SUDDEN DROP and I have nothing wrong with my car. I have a Subaru as well, and noticed the same radical drop in mileage. I have attributed this sudden drop to the gasoline. I tried a "smaller" gas station, and the mileage returned on both cars, but now the smaller station, too has poor MPG. I think the gas has less punch to it as I notice a lower performance on my "butt Dyno" also.....

Just my 2 cents....

[DaleJrDolphins]

BOBOLINKO---

You know....im no expert, but when I pulled my plugs I noticed one looked like it may have been "dead", and I noticed improved EVERYTHING once I changed them....i think that was around 50Kmiles for me.

[DaleJrDolphins]

So, I cleaned the MAFsensor, AND I drilled a bunch of holes in the bottom (pre-filter of course) of the Air intake box....since I didnt want to completely lose the box after I already ordered a K&N made to fit high performance filter and I also wasnt looking for a louder/throatier sound.
THANK YOU SOOO MUCH for teaching me this MAF cleaner tip! it seems to me like something you should be taught when youre taught to change the oil/air filter/etc!!! but for whatever reason I had never heard this one before.

[tooter]

There may be another cause for decreased mileage which has nothing to do with the condition of your Yaris... and that's the kind of gas you are putting into your tank.

Alcohol blends 5% 10% 15% E85's typically yield poorer gas mileage over straight gasoline. My 2012 even has a warning not to run E85 in it.

Present gas mileage everage is 39.2 mpg with almost no 5th gear freeway driving

[new-yaris-owner]

Fill up with high octane fuel once in a while will help ?

[baseballfan416]

Octane isn't the issue.

It's the fact that corn-based gas burns at a hotter temp, causing a thermodynamic nightmare (unless of course the engine is designed to handle e85).

[DaleJrDolphins]

SO, I just squirted some carb cleaner on the throat and now it wont start.........I cant find the cable to control the throttle myself either
PLEASE HELP ASAP!!
Yikes....that was scary...so after a half hour I shut the hood and try again and notice it didnt stall as quick and I wondered if there was too much air getting in there....so I put everything back together and eureka! it works perfectly! So I am figuring that because the MAF Sensor wasnt sensing any air and so it probably made the fuel so rich that it was stalling. Im wondering if anyone else had any thoughts about this....should I just say fudge it and not clean it? should I have someone else control the throttle from the drivers seat and barely open it up to stick the straw in and spray?

Happy Yaris-ing!
and by the way...i notice a TON of improvement after cleaning the maf and drilling holes in the bottom of the airbox.