Bad fuel economy - Toyota Yaris Forums

Yaris2468 · 03-17-2012, 01:05 AM

:

Yaris2468 · 03-17-2012, 01:21 AM

Also there is a lot of black carbon deposit in the exhaust. When I showed them at Toyota they said its normal though.

SAV912 · 03-17-2012, 02:56 AM

Is it a regular occurence or was it 400 KM on one particular tank?

If it was just one tank, it could be an anomaly. Bad winter gas, cold winter conditions, a particularly high amount of city driving...it adds up.

If it is ongoing, I'd recommend cleaning off the MAF and throttle body. That will complement the air filter and spark plugs. Possibly switch to full synthetic (5w/30, I run 0w/20 but that might be too thin for Canada) oil as well.

-C

Yaris2468 · 03-17-2012, 02:30 PM

Its been about 4 tanks like that. very consistent. I was told synthetic isn't the best for my car overall. the MAF and throttle body.. can I do that myself or does a mechanic?

SAV912 · 03-17-2012, 02:44 PM

The MAF is very easy to do, you just have to be very careful handling it. Two screws, a paper towel to sit it on, and time. That's all you need. The throttle body is a bit more difficult, but there are plenty of Do It Yourself/How Tos listed in the DIY Maintenance forum. As far as how consistent this is, I'd still be inclined to chalk it up to winter blends and cold temperatures. Of course, I can't say that is 100% your only reason.

Whoever told you synthetic wasn't the best for our cars is full of tartar sauce. The ONLY reason you wouldn't run synthetic is if you car is very old and has a ton of miles. Syn can loosen bits of sludge that have otherwise plugged a potential leak. But even an '07 shouldn't be that old that synthetic would pose a problem. I'd get it switched over pronto. It's a bit more expensive to run synthetic but the returns in fuel mileage and overall performance balance it out in your favor. I've run Mobil 1 FE 0W/20 the entire time I've owned mine, more than two years now. Hope this helps.

-C

daf62757 · 03-18-2012, 11:50 PM

I just went through a rough stretch of bad mileage. I started using Lucas fuel additive again and my MPG average went from 33 mpg to 40 mpg. You have to be consistent in your use and always have a bottle ready to pour into the tank.

SAV912 · 03-19-2012, 01:54 PM

SeaFoam would also likely help, if there are carbon deposits in the exhaust. It is a delicate procedure though and I wouldn't recommend doing the vacuum line portion without a buddy to help out.

-C

caper26 · 03-22-2012, 08:48 AM

Quote:

Originally Posted by daf62757

I just went through a rough stretch of bad mileage. I started using Lucas fuel additive again and my MPG average went from 33 mpg to 40 mpg. You have to be consistent in your use and always have a bottle ready to pour into the tank.

Which one of [THESE] do you use??

daf62757 · 03-22-2012, 09:38 PM

Quote:

Originally Posted by caper26

Which one of [THESE] do you use??

I use the middle one. The Lucas fuel treatment. I buy it in the gallon jug to save money.

One thing I have noticed is that Lucas had a genius to make the fuel treatment, but a complete moron to design the plastic bottles they come in. Every size I have bought leaks and causes a mess. I have wound up buying two small bottles and pouring the gallon jug into these smaller bottles and using them as I go.

caper26 · 04-16-2012, 02:08 PM

Excellent. Got my summer tires on today and a bottle of the FT, and will fuel up shortly and dump a bottle in the tank and see what happens!! Temp supposed to be up for next few days too (over 20 C)

caper26 · 04-16-2012, 06:40 PM

Also cleaned the MAF sensor and vacuumed out the intake box and air filter

curtmaxwall · 04-17-2012, 08:34 AM

There are lots of reasons behind the bad fuel economy. There are all system parts contributing in bad fuel economy due to their bad behaviors or lack of maintenance. The first thing would be the Air fuel ratio sensor, catalytic converter, oxygen sensor and rust in air filter and fuel filter. Maintain all fuel supply system parts in proper manner including fuel filter, fuel pump, fuel sensor etc.

caper26 · 04-17-2012, 10:11 AM

Car has only been on the road 1 year with 13,000 km. I hope nothing else is wrong besides what has been mentioned.

caper26 · 04-18-2012, 08:23 PM

I did some things are initially getting drastic results, but may be due to outside temps as well. check my thread 600/450 km in the FE forum if interested.

03-17-2012, 01:05 AM	#1
Yaris2468 Drives: 2007 Yaris hatchback automatic Join Date: Mar 2012 Location: Bc Posts: 3	Bad fuel economy : Last edited by Yaris2468; 03-19-2012 at 03:24 PM.

03-17-2012, 01:21 AM	#2
Yaris2468 Drives: 2007 Yaris hatchback automatic Join Date: Mar 2012 Location: Bc Posts: 3	Also there is a lot of black carbon deposit in the exhaust. When I showed them at Toyota they said its normal though. Last edited by Yaris2468; 03-19-2012 at 03:24 PM. Reason: :

03-17-2012, 02:56 AM	#3
SAV912 Pirate Yaaaaris View User's Garage Drives: '00 Toyota Celica GTS 6MT Join Date: Aug 2009 Location: Savannah, GA Posts: 573	Is it a regular occurence or was it 400 KM on one particular tank? If it was just one tank, it could be an anomaly. Bad winter gas, cold winter conditions, a particularly high amount of city driving...it adds up. If it is ongoing, I'd recommend cleaning off the MAF and throttle body. That will complement the air filter and spark plugs. Possibly switch to full synthetic (5w/30, I run 0w/20 but that might be too thin for Canada) oil as well. -C __________________ Georgia Bulldogs! '09 Yaris LB 5MT Sold.

03-17-2012, 02:44 PM	#5
SAV912 Pirate Yaaaaris View User's Garage Drives: '00 Toyota Celica GTS 6MT Join Date: Aug 2009 Location: Savannah, GA Posts: 573	The MAF is very easy to do, you just have to be very careful handling it. Two screws, a paper towel to sit it on, and time. That's all you need. The throttle body is a bit more difficult, but there are plenty of Do It Yourself/How Tos listed in the DIY Maintenance forum. As far as how consistent this is, I'd still be inclined to chalk it up to winter blends and cold temperatures. Of course, I can't say that is 100% your only reason. Whoever told you synthetic wasn't the best for our cars is full of tartar sauce. The ONLY reason you wouldn't run synthetic is if you car is very old and has a ton of miles. Syn can loosen bits of sludge that have otherwise plugged a potential leak. But even an '07 shouldn't be that old that synthetic would pose a problem. I'd get it switched over pronto. It's a bit more expensive to run synthetic but the returns in fuel mileage and overall performance balance it out in your favor. I've run Mobil 1 FE 0W/20 the entire time I've owned mine, more than two years now. Hope this helps. -C __________________ Georgia Bulldogs! '09 Yaris LB 5MT Sold.

03-18-2012, 11:50 PM	#6
daf62757 Nothing beats a Toyota! View User's Garage Drives: 2013 Yaris 5 dr liftback Join Date: Jan 2009 Location: Indianapolis, Indiana Posts: 564	I just went through a rough stretch of bad mileage. I started using Lucas fuel additive again and my MPG average went from 33 mpg to 40 mpg. You have to be consistent in your use and always have a bottle ready to pour into the tank. __________________ Big Dave Indianapolis, IN Synthetic Oil....its in my car.....for at least 10,000 miles!

03-17-2012, 02:30 PM	#4
Yaris2468 Drives: 2007 Yaris hatchback automatic Join Date: Mar 2012 Location: Bc Posts: 3	Its been about 4 tanks like that. very consistent. I was told synthetic isn't the best for my car overall. the MAF and throttle body.. can I do that myself or does a mechanic?

03-19-2012, 01:54 PM	#7
SAV912 Pirate Yaaaaris View User's Garage Drives: '00 Toyota Celica GTS 6MT Join Date: Aug 2009 Location: Savannah, GA Posts: 573	SeaFoam would also likely help, if there are carbon deposits in the exhaust. It is a delicate procedure though and I wouldn't recommend doing the vacuum line portion without a buddy to help out. -C __________________ Georgia Bulldogs! '09 Yaris LB 5MT Sold.

04-16-2012, 02:08 PM	#10
caper26 Drives: 2010 4D Sedan 5M w/convenience Join Date: Apr 2011 Location: Canada Posts: 86	Excellent. Got my summer tires on today and a bottle of the FT, and will fuel up shortly and dump a bottle in the tank and see what happens!! Temp supposed to be up for next few days too (over 20 C) __________________

04-16-2012, 06:40 PM	#11
caper26 Drives: 2010 4D Sedan 5M w/convenience Join Date: Apr 2011 Location: Canada Posts: 86	Also cleaned the MAF sensor and vacuumed out the intake box and air filter __________________

04-17-2012, 08:34 AM	#12
curtmaxwall Banned Drives: Toyota Yaris Spirit Join Date: Apr 2012 Location: NewYork Posts: 15	There are lots of reasons behind the bad fuel economy. There are all system parts contributing in bad fuel economy due to their bad behaviors or lack of maintenance. The first thing would be the Air fuel ratio sensor, catalytic converter, oxygen sensor and rust in air filter and fuel filter. Maintain all fuel supply system parts in proper manner including fuel filter, fuel pump, fuel sensor etc.

04-17-2012, 10:11 AM	#13
caper26 Drives: 2010 4D Sedan 5M w/convenience Join Date: Apr 2011 Location: Canada Posts: 86	Car has only been on the road 1 year with 13,000 km. I hope nothing else is wrong besides what has been mentioned. __________________

04-18-2012, 08:23 PM	#14
caper26 Drives: 2010 4D Sedan 5M w/convenience Join Date: Apr 2011 Location: Canada Posts: 86	I did some things are initially getting drastic results, but may be due to outside temps as well. check my thread 600/450 km in the FE forum if interested. __________________

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