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Poor gas mileage?

I just bought a 07 Hyundai 3 door hatchback with a 1.6 ltr engine. It has 9,000 miles on it. I am getting atrocious gas mileage. 22 to 23 miles a gallon with about 50% driving in city traffic and 50% interstate driving. What should I be looking out for? What is wrong? any ideas?

Consumer Reports says 28 MPG overall for the 2007 Hyundai Accent with the 1.6. How many tanks have you burned? A small sample is less reliable than a large one. Is the weather cold? Is the car all original (tires/wheels, etc.)? Are you driving conservatively? Lots of factors could be at play here. As you keep track of MPG in the weeks and months to come, you may find your MPG figures will approach the CR figures.

Automatic or manual? Do you drive like a little old lady or the Lady from Pasadena? How exactly have you measured the mileage?

Are you warming up the engine for more than 30 seconds before driving it? (You shouldn’t)

Do you use drive-up windows at banks and fast-food joints? (Both your gas mileage and your waistline will benefit if you park the car and walk into the establishment.)

Are the tires properly inflated? (If you haven’t checked the tire pressure–especially with winter temperatures–shame on you.)

Do you race up to red lights, or do you coast?

When you drive on the highway, are you driving in the 55-60 mph range, or in the 70-75 mph range. The gas mileage rating for your car was based on driving at 55 mph, whether that is realistic or not.

Do you ever tailgate other drivers? (Believe it or not, tailgaters get much worse gas mileage than those who do not tailgate. Ask for the explanation if you do not know the reason.)

Are you carrying extra unnecessary stuff around in the car?

Do you know what viscosity oil was used when the oil was changed by the previous owner? If the oil is not 5W-20, then your gas mileage will suffer somewhat. For that matter, do you know if the oil was ever changed by the previous owner? Why not have the oil changed (be sure to specify that you want 5W-20 grade oil), just to be sure. Just remember to NEVER have your car serviced by a quick lube place!

Since the advent of computerized engine controls, very little can be adjusted on modern engines, and as a result, poor gas mileage is invariably the result of either worn out parts or driver behavior. Since the car only has 9k on the odometer, it is not likely that any worn-out parts are involved, thus making it more likely that driver behavior is the root cause of the gas mileage that you are achieving currently.

If you imagine that there is a raw egg between your foot and the pedals (both gas and brake), this will help you to maximize your gas mileage. Very gentle application of the gas and the brake is the best way to best good gas mileage, and driving with a conscious effort to avoid breaking that imaginary egg will help you to do this.

Wow! Even 28 Or 29 MPG Sounds Really Low. We Drive Large V-6 American Cars That Average Higher.

MPG will probably be lower in cold winter driving conditions.

Are you averaging several tanks of gas? You can’t do just one or two and get useful information.

Does the gas you are buying contain ethanol? Ethanol reduces fuel economy. Try straight gasoline.

Are you letting the car warm up before you get in and go? This will cut into MPG. Fuel economy ratings don’t factor in warm-ups. Try a few tanks just getting in and going.

Make sure the parking brake is released.

Should the MPG not get up closer to or top 28-29, I would let the dealer know. This car should still be under warranty. Be sure they document your complaint in writing.
I wonder if you have a dragging brake that’s not fully releasing.

Do you ever smell gasoline, other than during and right after filling up?

If there is no “check engine” light what could,should the Dealer do? Perform their own mpg test? take the owners figures as “offical”? give the owner a seminar on what affects mpg?

The dealer can check out the car. They can use a scan tool to see if the engine is ordering a rich fuel mixture. This would show as Fuel Trims. They can check the scan information for many other things which affect fuel economy (engine coolant temperature, whether the engine computer is going into close loop operation, etc.)
These are some of the things the dealer can do. Will they make any checks, or fall back on standard B/S (er…er…I mean rational, reasonable, alternative explanations)? [This English! Somtime, she stick to roof of mouth, no?!]

Also, They Can Check For Something Dragging Or Hanging-Up.

The Dealer must justify doing these “check outs” in order for the warranty claim to be paid.

Is the customer saying “poor mpg” good enough to justify these check outs (in absence of a check engine light)?The Dealer does not want to “eat” what they must pay the mechanic.Or we could rely on SOP and cheat the mechanic.

Now if the customer claimed a brake pull or said he smelled what he considered odor from the brakes that should justify a brake check out.He may just get a Advisor or Manager test drive rather than a mechanic to check out the brakes,remember the complaint must be verified before dispatch (in theory).

Maybe some of the readers can post what happened when the claimed “poor mpg”

I bet “no check engine light no action”.

You could have a independant inspect,it is a option,and then work getting reimbursed if any concern is found. (use this tool after getting rejected by the Dealer)

I agree with oldschool.

In the absence of a CEL or any specific symptoms other than the unconfirmed “uses too much gas”, I don’t believe that a diagnostic scan would be done free-of-charge by the dealership. Think about it–Since a huge number of new car owners are convinced that their vehicle is using too much gas, dealerships would be doing all of this probably unwarranted (and un-warrantied) diagnostic work free-of-charge constantly. No business can afford to chase ghosts–so to speak–on their own dime.

If the OP is prepared to pay the cost of this procedure, then by all means go to the dealership. However, I would suggest that the OP first try implementing the suggestions that CSA and I made.

If the car is getting abnormally bad fuel mileage this means a rich mixture and the CEL should be coming on along with a code or two being set.

Getting into something like this can be a slippery slope when warranty is involved because warranty is not going to pay for checking a dozen things based on a complaint of bad fuel mileage.
On a car like this warranty is only going to pay for the direct replacement of a known bad part and maybe (and that’s a HUGE maybe) half an hour for all diagnosis.

With a rating of 28 and the OP getting 23 it’s quite possible that driving habits could be behind this. (And yes I know, no one on Earth abuses their car or drives them hard.)

It is Winter. Your gasoline might have 10% ethanol. If the weather is cold and you have the lousy mileage gasoline, you may only get 22 to 23 MPG. If you have highway mileage of 34, you are right on the mark. I guess you will have to wait for a long trip to find out anything. Which city traffic you are talking about can make a difference.

Depending upon where you live, winter mpgs can suffer big time. Losing 10-15% as compared to summer mpg results is typical. I typically get 22-23 in the summer, but consider myself lucky to get 20 mpg in the winter. Some of this has to do with less efficient gas (with ethanol), some has to do with driving through snow which increases drag, as does grease in the wheel bearings, transmission fluid and engine oil, all thicker when cold, all making parts harder to move in them.

22-23 does suck for an Accent. You should be getting at least 25 with your type of driving, probably much more. If you take it out on a highway trip (at least 50 miles) and it doesn’t produce a reading higher than 30 mpg, you have a problem.

One last question - are you going to the same filling station each time and pulling the nozzle out the filler neck after the first time the pump shuts off? I know that if I check gas mileage while using different filling stations, sometimes even different pumps at the same station, it throws the mpg rating off. Different pumps shut off at different points in the filling process, leaving you with up to a .5 gallon more or less, causing an inaccurate gas mileage reading.

I actually AM a relatively old lady (55) and drive like one. It’s funny because it is true. I live 10 miles from work. 3 mi city, 7 mi highway. Time is 50% on hwy and 50% city.

The Hyundai is an automatic. No check engine light.

I am neurotic about checking air in the tires and do that at least once a week. My last car was a 90 Tempo so I checked everything once a week. I am amazed by the Hyundai mileage as I got 23 avg mpg in the Tempo.

I live in Texas so cold isn’t really cold. I know that there are winter additives here though so thanks for that.

I carry nothing in the car except myself and groceries sometimes. I am not a plus size girl. No large dog, no cargo. Extra shoes sometimes…

I bought it about a month ago and have measured 3 tanks of gas by using the trip meter and the info from the gas pump. My brother thought that it might have been that the previous owner used low octane gas and recommended that I put mid grade in it for a few times to see if that would help. So I have been using 90. I have no idea what the dealership put in it.

I took it back to the dealership yesterday to see if they could find a problem (maybe dirty injectors?) but they said everything checked out with a diagnostic check and to take it to the dealer.

As far as I know the equipment is all original. I will continue to monitor the mileage and please give me any more ideas that occur to you.

Anyone know what mileage you need to change to synthetic oil?

What do you mean when you say the said to you, “take it to the Dealer” did you buy from a non-dealer? (nothing wrong with that)

I am 54 don’t feel like a old man

Are you asking how long you should run on mineral oil before you switch to syn?

Don’t expect any mpg increase by using a higher octane fuel than required.

Did they give any idea how elaborate the diagnostic check they did was?

You drive 10 miles to work, and back(?) You probably drive less than when you drove the other car. This less time, and mileage, results in a larger percentage of time that the engine is warming to operating temperature.
It won’t reach the EPA figures because of the cold engine periods.
The check engine light isn’t dependent upon engine efficiency. It is turned on when faulty signals are detected from components; or, when the emissions worsen by 150% – as mandated by EPA’s OBD II standards.

Your question about synthetic oil is really a question about oil change interval, in my mind. Check the owner’s manual for the maximum interval. Based on your driving conditions, it appears the regular, non-severe service interval can be used. Since it appears the car is still under warranty, stay within the oil change interval parameters. You can use either conventional or synthetic oil at the oil changes, your choice. Since my cars are out of warranty, I use a 7500 mile interval for synthetic and 5000 mile interval for conventional, or once per year, whichever comes first. These intervals allow me to retrieve the extra cost of synthetic by extending the synthetic interval 50%. You may or may not want to do this, and whatever you do, stay within the warranty oil change interval parameters for Hyundai.

I think I would let it go for now. It appears you are within about 10-13% of the EPA mileage, and my own gas mileage can vary 10% from one tank to another, due to driving habits, winter warm up time, and other factors.

On a different level, I can also say that I continue to be disappointed in the gas mileage I get on many rental vehicles similar to the Accent. The gas mileage in these rental cars aren’t that much better than cars I rented in the 80’s & 90’s, and one would think that car manufacturers have made enough improvements in this area, but haven’t. So far, this year, a Kia Rio has given me the best mileage (haven’t rented a Corolla or Civic recently). Dodge Neon and the Caliber have consistently provided me with very poor mileage for size of car.

I hope you don’t mind if I share your question. I’m in the same boat, but have a much older car. I haven’t actually sat down to calculate mpg, but since I drive my car so much I feel like I can tell that it’s eating more gas lately without having to actually calculate that. But if you feel I should, after you’ve read my question, please let me know, because I’m happy to figure it out.

I drive a 98 Honda Civic DX with 231,000 miles on it. I know the gas mileage isn’t what it used to be, and I’m O.K. with that. However, over the past couple of weeks, I’ve noticed my gas is disappearing more quickly than it usually does.

I have a long commute (roughly 40 miles one way) and I start my day in the early morning hours when it’s cold out. I do not sit there and run the engine in the morning; I turn it on and go. Unfortunately, I am a leadfoot, but I keep it at 65 mph. 90% of my commute is on highways, where the speed limit is 55mph. I get regular oil changes and try to take care of my car as best I can, but it isn’t always financially possible. I’ve had the engine flushed recently, as well as a transmission flush within the last 6-7 months or so.

Based on the things you have asked the original poster, I do not have excess things in my car, I do tend to race up to some lights, I tailgate sometimes (I am not proud of this!), and it’s an automatic. But none of this has become more or less over the past couple of weeks, that I can tell, so I’m not sure if it’s my driving habits or not. Oh, also, I live in Northern CA, so it’s cold, but it’s not that cold. Actually, the mornings the past couple of weeks have been the warmest mornings we’ve seen a month or two. I run the heater, but not a lot. Just enough to where I feel warm, and then I turn it off.

Nothing has changed over the past couple of weeks, as far as my commute, driving, tire pressure, etc. so I’m curious what else could be causing the gas mileage to change. Any ideas?

My first thought was that maybe I developed a hole in my gas tank, because that actually happened with one of the cars at work! Where I work, the road is gravel, and if you drive fast enough or hit the right bumps, the rocks will fly up underneath your car and you’ll hear them hitting the bottom. I’ve often wondered what kind of damage would be found underneath my car if I allowed someone to look.

Also, your tips are fantastic, especially the rotten egg one, and I plan to put most, if not all, of these to use. I am an aggressive driver and I do not like this about myself, so getting better gas mileage is (hopefully) going to convince me to change.

It’s your driving habits,Why do you think running the heater could affect your mpg?

VBishop and Walrus,
There are just so many things which can cause low mpg; but, we can cover a couple of them. I’m wondering if both of your engines are going into “closed loop” (CL) operation. When the system is in CL, the engine computer is controlling the engine for the best fuel/air operation. If it stays in OL (open loop) the engine will run richer and have lower mpg.
You can take your car to an auto parts store and ask them to scan it. If it scans with a CL, and if all the monitors are complete (run), that part is, probably, fine.
On an older car (usually) the engine thermostat can stay open, the engine doesn’t fully warm, and the engine computer can’t go into CL.
If the engine does heat, but the engine coolant temperature indication or, (iat) intake air temperature sensor) to the engine computer reads “cold”, the engine computer won’t go to CL.