21 MPG whats wrong

[P205]

I have a 2008 yaris sedan Automatic 100% city driving

afe intake
new spark plugs
tightly inflated tires
I drive like a little old lady
usually im the only passenger 155 pounds
I cleaned my maf sensor,made sure it was sealed well
no AC
i don't let it idle for no reason
I feel like im doing everything i can possible do right but still
all summer iv been getting 21 mpg, winters here and im lettting it warm up for about 2 mins still 21mpg

[Altitude]

Start with the easiest...

How did you arrive at the number? Do you have a scangauge or similar? Are you sure you're using the right values in your calculation?

[P205]

i am getting 218 miles to my tank. on a 10 gallon tank

[jpmck03]

You completely filled the tank with exactly 10 gallons on your last fill-up? Methinks you are messing up some math there or goofed on something or another...

[Kar98]

Originally Posted by jpmck03

You completely filled the tank with exactly 10 gallons on your last fill-up? Methinks you are messing up some math there or goofed on something or another...

Give the man some credit. I'm sure he's able to divide a three digit number by ten. My bet would be with bad gas.

[P205]

Im lost, dosent this seem like bad mpg for my situation? i use sevral diffrent gas stations around

[rningonfumes]

How many tanks of 21 mpg have you been getting?

[P205]

i have had maybe 8 tanks through it since I've owned it

[tooter]

Just for fun... I'd try disconnecting a battery cable for a few minutes so that the ECU can go dumb, and then reconnect, fill up, drive normally, log your mileage for a tank and see if there's any change.

This is an easy test that costs you nothing.

[NEexpat]

Well.................

This is a real head scratcher................21 mpg is about half of what I get in the summer. From your posts I am gonna guess you are not driving around in 3rd instead of drive, also gonna guess you are not leaking fuel anywhere. If it were an isolated incident I would have guessed maybe someone is pulling your leg and stole some gas out of your tank.
Unless it is somekind of ECU problem like tooter said,.................. but boy 21mpg.

Wish I had a suggestion for you, good luck.

[Altitude]

Originally Posted by P205

Im lost, dosent this seem like bad mpg for my situation? i use sevral diffrent gas stations around

Yes, that is horrible MPG. It's 1/3 to 1/2 less than the norm. You might have a leak or as NEexpat said, someone might be siphoning it out of your tank.

Take it to a shop and have them hook up a scanner and check for any codes.

[jpmck03]

Originally Posted by Kar98

Give the man some credit. I'm sure he's able to divide a three digit number by ten. My bet would be with bad gas.

I wasn't trying to suggest that he was a complete dolt or anything like that... just that maybe he transposed a number or something when he was doing his arithmetic.

I know I've done it before...

Hopefully, P205, you get it figured out!

[alpha1]

City driving would be for the average city driving. Ex. of others experience with a yaris http://www.fueleconomy.gov/feg/Find....hicle&id=25894
Perhaps your city is not average and very very congested with backups due to airports etc. making you sit and idle on the road.
Many variable like warm up/ idle time/ sitting in the car running the heater/ac listening to music/ foot riding the brake/emergency brake on/ air filter needs to be cleaned/

If above is good, definitely inflate your tires to a higher psi if possible; empty excess weight from the vehicle; check for other maintenance issues.

Other good idea: http://www.yarisworld.com/forums/showthread.php?t=39818

[rningonfumes]

Okay, something is really wrong in my opinion. Most of us would have to gun it and all out throttle every where we go to even touch 30s.

How short are your trips? You may be letting it warm up for 2 minutes but you are in Alaska. This is summer numbers for you? Really short trips combined with low temperature climates might show that your engine isn't warmed up at all and you're constantly driving with the engine trying to warm up.

If it is the case that you have really short trips, for one tank try going on longer trips.

I'm also going to ask some very stupid questions not saying that you are necessarily the stupid one. We've had to ask this before to others:
1. Are you sure you're not driving in 3rd?
2. Are you sure you're not driving with the parking brake on?
3. Does the cold engine light actually go off?
4. How old lady is your "old lady driving?"

Sounds like you're doing everything right so far.

[e39a]

Tire size? Cylinder compression issues?

[P205]

my trips are very short 2 miles to work, 2 miles to the girlfriends house.
When you say driveing in 3d. it shows d3 on the trans switch so i put it on D3
its an automatic cold engin light usaully i drive when its out. half the time i take off when i think its about warm to go then the light gose out before im out of my street
and for driveing like a old lady. i take of very slow at every stop never accel fast. never hit over 45

[rningonfumes]

That'll do it. 2 miles is very short.

About the driving in 3D.... One side is D ( all gears to include 4th) and one side is 3 for 3rd gear. Are you sure you're on the "D" side. Again this issue has come up before with people not familiar with gated shifters.

I'm going to call it on the 2 miles. To be sure, try going out for a longer distance for just one tank. This means pulling in 5 + miles on work (to and from) and the girlfriend's house (to and from).

[P205]

allright i have been driveing in 3 this hole time