Where is my gas going? - Toyota Yaris Forums

Keith Tinari · 10-06-2009, 08:27 AM

When I bought this car I was averaging around 40mpg. Thats great maybe almost worth the WRX trade in. I did some small mods, lowered, light wide wheels with a tire comparable in height to the stock ones, the TRD exhaust, and a K&N drop in. Reset the ECU and now I'm getting around 30mpgs. It never gets driven hard because its a Yaris, I'd still get there late lol. I also did the break in, and the 1500 and 3000 mile oil changes. I'm running 5-30 oil and 87 octane like Toyota suggests. Any ideas?

Tamago · 10-06-2009, 08:29 AM

probably all those "power" mods you've been blowing your money on

in all seriousness, it's the wide tires that are doing it.

Keith Tinari · 10-06-2009, 08:39 AM

youre kidding me really? when I was on the advans I was running the same tires and still getting around 40! too much rolling resistance?

thebarber · 10-06-2009, 09:18 AM

wide tires hurts the mpgs for sure.

im running 205's and im down a couple mpg's

Tamago · 10-06-2009, 09:43 AM

yes, and those silly "power" mods are doing it too. what's your AFR's looking like?

Keith Tinari · 10-06-2009, 09:50 AM

I have no clue to be honest. I didnt buy either of them for power. I just didnt want to ghetto the car up with a big tach so I put an exhaust on it to hear it. Im not used to quiet cars like this. My old Subaru used to set off car alarms. and the K&N I thought would help MPGs get better.

BTW Barber I am running 205 50 15s on 15x7.5s, I guess the footprint is rather large for a car this size. This pretains to nothin but with a half tank of gas and me in it my car weighs 2520. I thought that was cool.

TLyttle · 10-06-2009, 12:26 PM

My guess would be the tires: wide tires eat gasoline, simple as that. Colder weather doesn't help. I've used K&N filters, to the detriment of fuel mileage. I don't think the exhaust system change helps much either.

Anything you do to increase performance (acceleration) is going to show up on your pump bills. Performance means ALL PHASES of the car, not just acceleration, and includes fuel economy. The Yaris seems to be a very tightly-balanced car, and changes are likely to upset that balance...

Tamago · 10-06-2009, 12:47 PM

Quote:

Originally Posted by Keith Tinari

I have no clue to be honest. I didnt buy either of them for power.

you didn't buy them for better fuel economy either ;)

oh, and if you're lowered, you've created a great deal of toe-in at the rear of your car. this is another cause of bad fuel economy. get that rear toe fixed

b_hickman11 · 10-06-2009, 01:11 PM

Quote:

Originally Posted by Tamago

you didn't buy them for better fuel economy either ;)

oh, and if you're lowered, you've created a great deal of toe-in at the rear of your car. this is another cause of bad fuel economy. get that rear toe fixed

and thats the only 2 reasons?? I think not.

jambo101 · 10-06-2009, 01:20 PM

Coming from a WRX and with all the mods you've put on the car i'm suspecting your idea of easy driving is whats netting you 30mpg,i'll bet if my idea of easy driving were put to your car you'd be back up to 40+mpg.Doesnt take much to ruin a good mpg result on a tank of gas.

SpaceShot · 10-06-2009, 01:57 PM

Use a digital gauge and check the tire pressure. With a wide low profile tire you might not even notice it being toward the low side. Try it for a week with 32psi (if not already there), and then a second week at something closer to the max sidewall rating.

Consider an ecometer or scangauge II. You don't think you are driving hard, but the near instant feedback may tell you otherwise. With some practice you can get used to coasting with the terain along your route and see your trip average Mpgs start going back up.

Also as the weather gets cooler you will drop a couple Mpg. Look at your route and see if you can find a way to be on the side roads a few extra minutes before hitting the freeway in the morning. For the winter consider blocking the lower grille below the bumper.

Tamago · 10-06-2009, 01:59 PM

Quote:

Originally Posted by b_hickman11

and thats the only 2 reasons?? I think not.

english lesson time. i said "another" not "the only other"

Keith Tinari · 10-06-2009, 02:09 PM

Quote:

Originally Posted by SpaceShot

Use a digital gauge and check the tire pressure. With a wide low profile tire you might not even notice it being toward the low side. Try it for a week with 32psi (if not already there), and then a second week at something closer to the max sidewall rating.

Consider an ecometer or scangauge II. You don't think you are driving hard, but the near instant feedback may tell you otherwise. With some practice you can get used to coasting with the terain along your route and see your trip average Mpgs start going back up.

Also as the weather gets cooler you will drop a couple Mpg. Look at your route and see if you can find a way to be on the side roads a few extra minutes before hitting the freeway in the morning. For the winter consider blocking the lower grille below the bumper.

I actually have them set currently at 32 psi, using my very expensive gauge at work. (I'm a mechanic) I tried closer to 40 and it made the car a little too rough. I used to run 45 in my Subaru but it wasnt as uncomfortable as this car is at that PSI. I have to admit I dont do much coasting because my drive consists of mostly hilly windy backroads. And when you get off the throttle it takes forever to get back to 45. I equate this car to a small motor with a large turbo at very very low boost lol. I just wanted to make sure there wasnt something wrong with this car. Our Motis at work cannot connect to my car so I cant see fuel trims. is there any software for our cars?

Subarus use a program called open ECU where all you need is the free software, a Tactrix cable and a laptop to see everything and tune. My tuner used it reliably to tune my car at 21psi with 565cc injectors and still keep the IDC at around 75% and optimal AFRs.

Tamago · 10-06-2009, 02:33 PM

yes, it's called a scangauge. already mentioned in this thread. ;)

Loren · 10-06-2009, 04:20 PM

I'm running 215/45-15 Toyos and can still net 40 mpg regularly around town and 44+ on the highway.

My guess is the OP's problem is that he's made significant "sound" mods. A car that SOUNDS good inspires the driver to drive it such that it can be heard.

Tamago · 10-06-2009, 04:35 PM

Loren! good to have you back!

ROCKLAND TOYOTA · 10-06-2009, 04:53 PM

Quote:

Originally Posted by Keith Tinari

It never gets driven hard because its a Yaris, ?

1stToyota · 10-06-2009, 04:53 PM

Quote:

Originally Posted by Keith Tinari

I actually have them set currently at 32 psi, using my very expensive gauge at work. (I'm a mechanic) I tried closer to 40 and it made the car a little too rough. I used to run 45 in my Subaru but it wasnt as uncomfortable as this car is at that PSI. I have to admit I dont do much coasting because my drive consists of mostly hilly windy backroads. And when you get off the throttle it takes forever to get back to 45. I equate this car to a small motor with a large turbo at very very low boost lol. I just wanted to make sure there wasnt something wrong with this car. Our Motis at work cannot connect to my car so I cant see fuel trims. is there any software for our cars?

Subarus use a program called open ECU where all you need is the free software, a Tactrix cable and a laptop to see everything and tune. My tuner used it reliably to tune my car at 21psi with 565cc injectors and still keep the IDC at around 75% and optimal AFRs.

Quote:

Originally Posted by Tamago

yes, it's called a scangauge. already mentioned in this thread. ;)

Or a Genisys

Just hooked mine up a few minutes ago for fun; full datastream info for my engine, etc...and my tires ranged from 68-70 degrees, 33.4-33.7 psi

10-06-2009, 08:27 AM	#1
Keith Tinari Scrubble with a poke. Drives: 2009 Yaris LB Join Date: Jul 2009 Location: Holland PA. Posts: 166	Where is my gas going? When I bought this car I was averaging around 40mpg. Thats great maybe almost worth the WRX trade in. I did some small mods, lowered, light wide wheels with a tire comparable in height to the stock ones, the TRD exhaust, and a K&N drop in. Reset the ECU and now I'm getting around 30mpgs. It never gets driven hard because its a Yaris, I'd still get there late lol. I also did the break in, and the 1500 and 3000 mile oil changes. I'm running 5-30 oil and 87 octane like Toyota suggests. Any ideas? __________________ "If you cannot find truth right where you are, where else do you expect to find it?" Dogen

10-06-2009, 08:39 AM	#3
Keith Tinari Scrubble with a poke. Drives: 2009 Yaris LB Join Date: Jul 2009 Location: Holland PA. Posts: 166	youre kidding me really? when I was on the advans I was running the same tires and still getting around 40! too much rolling resistance? __________________ "If you cannot find truth right where you are, where else do you expect to find it?" Dogen

10-06-2009, 09:18 AM	#4
thebarber daily driver View User's Garage Drives: the #wrecho Join Date: Jun 2006 Location: Grand Rapids, MI Posts: 5,877	wide tires hurts the mpgs for sure. im running 205's and im down a couple mpg's __________________

10-06-2009, 09:50 AM	#6
Keith Tinari Scrubble with a poke. Drives: 2009 Yaris LB Join Date: Jul 2009 Location: Holland PA. Posts: 166	I have no clue to be honest. I didnt buy either of them for power. I just didnt want to ghetto the car up with a big tach so I put an exhaust on it to hear it. Im not used to quiet cars like this. My old Subaru used to set off car alarms. and the K&N I thought would help MPGs get better. BTW Barber I am running 205 50 15s on 15x7.5s, I guess the footprint is rather large for a car this size. This pretains to nothin but with a half tank of gas and me in it my car weighs 2520. I thought that was cool. __________________ "If you cannot find truth right where you are, where else do you expect to find it?" Dogen

10-06-2009, 04:20 PM	#15
Loren What? Drives: 2007 Yaris LB Join Date: Nov 2008 Location: Safety Harbor, FL Posts: 1,006	I'm running 215/45-15 Toyos and can still net 40 mpg regularly around town and 44+ on the highway. My guess is the OP's problem is that he's made significant "sound" mods. A car that SOUNDS good inspires the driver to drive it such that it can be heard. __________________ ----------------------- Loren@InvisibleSun.org -----------------------

10-06-2009, 12:26 PM	#7
TLyttle Drives: 07 Yaris sedan Join Date: Jun 2007 Location: Keremeos BC Posts: 986	My guess would be the tires: wide tires eat gasoline, simple as that. Colder weather doesn't help. I've used K&N filters, to the detriment of fuel mileage. I don't think the exhaust system change helps much either. Anything you do to increase performance (acceleration) is going to show up on your pump bills. Performance means ALL PHASES of the car, not just acceleration, and includes fuel economy. The Yaris seems to be a very tightly-balanced car, and changes are likely to upset that balance...

10-06-2009, 01:20 PM	#10
jambo101 Drives: yaris 08 sedan Join Date: Oct 2008 Location: Montreal Canada Posts: 1,286	Coming from a WRX and with all the mods you've put on the car i'm suspecting your idea of easy driving is whats netting you 30mpg,i'll bet if my idea of easy driving were put to your car you'd be back up to 40+mpg.Doesnt take much to ruin a good mpg result on a tank of gas.

10-06-2009, 01:57 PM	#11
SpaceShot Drives: 2008 Yaris 5 speed HB Join Date: Oct 2008 Location: NH Posts: 171	Use a digital gauge and check the tire pressure. With a wide low profile tire you might not even notice it being toward the low side. Try it for a week with 32psi (if not already there), and then a second week at something closer to the max sidewall rating. Consider an ecometer or scangauge II. You don't think you are driving hard, but the near instant feedback may tell you otherwise. With some practice you can get used to coasting with the terain along your route and see your trip average Mpgs start going back up. Also as the weather gets cooler you will drop a couple Mpg. Look at your route and see if you can find a way to be on the side roads a few extra minutes before hitting the freeway in the morning. For the winter consider blocking the lower grille below the bumper.

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