[thesilverone10]

After last time I filled up I reset the trip meter and today I filled up it said I drove 61.4 miles and put it 3.038 gallons. That equals 20.21 mpg. It is a 2010 with 43000 miles. I dont know what could be wrong for it to be getting so low mpg. I don't floor it at all. It has a clean air filter, oil changed recently, tires at 30psi, 87 octane shell and bp gas. I did use the AC a couple days last week when the weather was hot but it shouldnt use that much gas at least I wouldnt think. Any help as to what could be wrong before I bring it in? Check engine light isnt on. Doesnt seem to have any loss of power which really puzzles me too .

 

[cd32409]

Straight line winds? Clogged fuel injectors? High speeds/rpms? (even if you don't floor it)


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[thesilverone10]

I guess ill try some fuel injector cleaner and see what happens. Its an automatic and I rev up to 3000 rpm before it shifts. I should be getting well above 20 mpg average in a car like this.

 

[jeepnuts311]

If your state's epa/emissions regs are like Georgias, Then it is about time for your gas stations to be switching over to summer gas, which always gives you worse fuel economy than winter gas. We switched over about a month ago, but it gets hotter earlier here in GA.

You should be getting better than 20, but your car probably didn't like that first tank of the new blend, I'm betting you get some back the next tank. Should be running at least high 20s/low 30s even with AC on in the summer.

-Tim

 

[LeanBurn]

I am not sure I have ever seen someone top off the tank after driving only ~60 miles. It doesn't give a very good picture over all. I have driven 60 miles and got more than 51 mpgUS on the dashboard readout as an average...and then the rest of the tank balanced it out to the low 40s.

It would also help to know what kind of setting you are driving in ie all city, lots of hills.

If you are after fuel economy look at pumping up your tires a little more than 30 psi, mine are set to 36-40psi.

 

[jeepnuts311]

Leanburn is right, I didn't even pay attention to the miles driven or gallons pumped in your post, just assumed you'd filled up.

An old nozzle or a fuel station that does not use stage 2 vapor recovery could pop the nozzle off earlier than another station that does use stage 2. It is possible that you weren't all the way full the first time, a half gallon more the second time around changes your equation quite a bit. up to 24mpg, you really need a full tank to give you a good average.

You can travel 0 miles on 1 gallon if you're idling, also you can travel closer to 40 miles on a gallon if you're coasting quite a bit.

More on summer gas...
http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/summer-fuel.htm
http://www.theoildrum.com/node/2374

 

[cd32409]

Yeah the summer swap over is always rough...I had a 95 grand am when I lived in Atlanta that normally got about 26-30 but the first month or so it'd drop down to low 20s.

In my corolla I still only notice a difference when passing through there as I don't think Mississippi has crossed over quite yet.


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[thesilverone10]

Its mostly flat not too many hills and mostly (90%) city driving. Im going to put some fuel injector cleaner in there and see if that helps any. So you are saying that I should wait until the fuel tank is empty and calculate the mileage on filling up the tank from empty? Im going to see if I get better mpg. Otherwise into the dealership ill go.

 

[thesilverone10]

Im just mainly concerned why Its as low as 20mpg right now thats my main concern. The dash says 20-22 mpg average also (goes up and down as I am driving).

 

[sinnaever]

60 miles is no where near enough to base your fuel efficiency on. Drive a few hundred, and fill up when you are below a 1/4 and calculate again.

You said 90% city is your daily driving, so if you are driving in stop and go for 60miles then you will be about 20mpg... Try basing it on more miles.

As for tips, check your filters, tire pressure, and make sure you don't have a kitchen sink in your trunk. Check your brakes for proper engagement because a sticky caliper would wreak havoc on your MPG.

 

[emptyminded42]

60 miles is no where near enough to base your fuel efficiency on. Drive a few hundred, and fill up when you are below a 1/4 and calculate again.

You said 90% city is your daily driving, so if you are driving in stop and go for 60miles then you will be about 20mpg... Try basing it on more miles.

As for tips, check your filters, tire pressure, and make sure you don't have a kitchen sink in your trunk. Check your brakes for proper engagement because a sticky caliper would wreak havoc on your MPG.

+1 I got around 20-22 mpg around my college campus (lots of stop signs and lights) for the 3 years I had this car at school, so having low mileage isn't unusual (I have a 2010 S auto). I agree with the sentiment of going further before you fill up, too, so I a) wouldn't worry about it and b) go to a 1/4 tank before checking your mileage.

EDIT: I will point out, however, that my car does fine on the highway (35+) and averages around 30 mpg in more normal "commuting to work" scenarios (more highway than surface roads).

 

[SmashedPumpkins]

Leanburn is right, I didn't even pay attention to the miles driven or gallons pumped in your post, just assumed you'd filled up.

An old nozzle or a fuel station that does not use stage 2 vapor recovery could pop the nozzle off earlier than another station that does use stage 2. It is possible that you weren't all the way full the first time, a half gallon more the second time around changes your equation quite a bit. up to 24mpg, you really need a full tank to give you a good average.

You can travel 0 miles on 1 gallon if you're idling, also you can travel closer to 40 miles on a gallon if you're coasting quite a bit.

More on summer gas...
http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/summer-fuel.htm
http://www.theoildrum.com/node/2374

My guess is this is your problem.

 

[SuperchargedMR2]

Most things have been covered already. No need to freak out over a top off of only 3 gallons & 60 miles. There is no way that can be overly accurate with such a small sample. If you were driving in city trafic with the a/c on who knows. I get around 17 mpg going up the hill to my house but it all evens out in the long run. Your tires are too low also so add some air in them. I never run below 35 psi in any car so 30 seems really low & will hurt your mpg. Always fill your tank when around 1/4 tank & over time you will get a great idea of your mpg. If something is wrong then it will show up quickly. On my 94 Corolla I had a bad O2 sensor & I saw the average mpg go from the low 30's to 21 mpg over 2 tanks. Got it fixed & it went right back up to 33 mpg. :thumbsup:

And one more thing....sign up at Fuelly.com so you can easily track everything. :clap:

 

[thesilverone10]

Shweet. Hey thanks a lot for Ur help. :thumbsup:

 

[FlawedLegacy]

moved to correct sub forum

 

[robcy]

I did a few weeks in the city last year for work, and the Accent that I drove at the time did 21 mpg over 2 tank fulls. Normally it did around 32 mpg. But the constant stop, and go, and traffic jams killed my mileage.

I agree that 30psi on the tires is low, but don't expect 30+ mpg with 90% city driving unless you get a hybrid.

 

[anomaly]

i was getting around 28-30mpg (24mph avg. speed) for a while then took my tire pressure up to 36-38psi and now im getting 32-33mpg. this is with me driving "spirited" in city traffic were i rarely get to stay at the speed limit for very long before someone needs to slowdown and turn or a light turns red. i feel id probably get around 35 or more if i could lay off the gas pedal.

i do notice around 37psi and up on the stock "S" wheels and tires that wet traction starts to fade fast... id say 35-36 is the sweet spot for me.

i also dont carry much weight with me in the car. im 220lbs my back pack is about 30lbs and i have a light weight sub-woofer set up that weighs in at just 24lbs (wires and all). as far as random junk i keep it to a minimum, 5lbs including things like phone charger, snow scrapper and owners manual, etc.

one of my best friends has a 2009 Le auto. he gets like 24mpg in the same city driving like a grandma, but hes also got maybe 400lbs of crap in his car and no real maintenance done after the free ride at Toyota ended.

 

[SuperchargedMR2]

i do notice around 37psi and up on the stock "S" wheels and tires that wet traction starts to fade fast...

FYI, hydroplanning is reduced with higher tire pressure so you may be experiencing something else.

 

[anomaly]

never said the word "hydroplaning", but yea. thanks for the wink.

I was referring to starting from a stop and losing traction while in a turn.

I have several sharp turns around town that i have enter/exit speeds memorized before the tires start to screech. i started noticing screeching at much lower speeds after 36/38psi (front/rear). the effect seem exponential the higher you go after that point on the stock S wheel package.

im currently running 36/38 as a "best of both worlds" approach (handling/rolling resistance) but im not trying to trash my tires in hopes of slightly better MPG so im monitoring the center of my tread for now.

seems counter productive to have to pay for tires prematurely just to save a buck or three every fill up.

 

[LeanBurn]

If you are running the sub par stock rubber they are well known for their inability to handle well and low tread life.

FWIW, there have been several tests done on hypermiler websites that show no significant increased wear from having the pressure closer to the usual side wall max of 44psi compared to near stock pressure levels, (not that I endorse going that high or higher) and some report even longer life out of their tires at higher pressures.

I have run 36-38psi on my car tires for years and always got excellent mileage out of them. I am currently running 40psi with no issues and if anything handling response seems increased.