So I've had my 09 Sonata Limited I4 for about 4000 miles, and I'm not experiencing the increase in MPG that I thought I would. MY daily commute is about 8 miles, half in the city, half on the highway. Even with consistently tame driving in both conditions, I seem to hover around 21-22 mpg combined. That can't possibly be right, can it? And yes, I am using the Sonata's computer to compute my average for a tank, but I always do a quick calc when I fill up and have found that the computer is usually close enough. I'm wondering if in their haste to get me my new car (when i bought it, it was completely wrapped in plastic, and had to be "prepped" for a day before I could take it home) if something got missed engine wise, and maybe that's why i'm getting worse than expected mileage. Am I crazy? Has anyone else experienced this? Let me know.

Thanks,
Brad

Darn you could have had a V6! Give it some time Brad as the Sonata should improve.

When they 'Prep' the Car (if they really do anything at all?) the Engine is not

touched. :57:

You have sort of a short drive. Engines tend to operate the most efficiently after driving a decent amount of distance (I'm not sure whether 8 miles qualifies). Especially with a 1/2 mix of city/highway, I would expect a little bit higher MPG, but 22 isn't the worst I've seen for an I4. I'm assuming this is 8 miles each way, right?

I'm not car savvy so let's see what other posters say.

its absolutely because of your commute..

8 miles.. half city half highway.. that means you are on the highway for less than 5 miutes? you're never going to get "near 30 mpg" mileage with an 8 mile commute, even with the I4.. your car hardly has time to warm up before you turn it back off... put it in perspective to my commute.. 37 miles each way, 95-97% highway (i have the V6) and i average above 27 mpg (in the summer i average well over 28)...i have 47k miles on the car and i give my car a chance to warm up on the highway.. the first 10-15 miles you drive in your car for the trip will not give you as good of mileage as the rest afterwards.. your trip doesnt allow for that....

also, 4k miles isnt exactly an engine that is really "broken in".. once you get past 10k - 15k miles, that's when your real mileage increase will happen....

Try inflating your tyres from 30psi to 32psi.....should help

could even go up to 34... but if your PSI is at 30, as faisalmg said, i would put a bit more air in them...

My 06 LX V6 did not start a mileage increase until after 10,000 miles. I've heard many reports of the same from other Sonata owners. At least for the V6 10,000 to 12,000 miles seems the magic point for MPG.

I have a new 08 i4 4 speed auto-- 4000 km on the odometer. My last couple of fillups work out to 7.4L/100 km which is 31 to 32 US mpg. My trips are 25 miles to town with quite a grade on the return. I find that the mpg computer is right on. The only thing is that I become fixated on it --- certainly has made me a "hyper" driver.
This mpg is not as good as I ecpected but is acceptable considering the size of this car. Looking forward to a 500 mile trip to see what I get.

31 to 32 US MPG is not what you expected??? seriously? that's pretty good mileage, even for the I4...

however, i have found that the trip PC is never "right on".. in fact, mine can be off 1-2 MPG from manual calculation and is not uncommon to be off that much..

Hey bigdog
Our commutes sound about the same. My 06 4 gets between 22.6 and 23.9 depending on my foot. Let's hope you improve.

I figured it had alot to do with my short commute, but I just wanted to run my situation past everyone and see if anyone had any ideas. Thanks for the feedback.

Well I do 70 highway, 30 city. 40 miles a day. Getting 30-32 MPG, without hypermiling.
Try to reset ecu ad go for 100/200 miles highway ad see what happens.

Short commutes are alays KILLING your gas mileage (and your engine too...). Especially when you drive at high speed with the engine not yet at operting temperature, like in my case.... 6.5 miles commute each way, and we live 2 miles from the expressway.... I now have 20,000 on the odometer and my average is 24 mpg. But taking her for a long trip, driving 2-3 hour at a steady speed of 65-70, I was getting 33-34 mpg, so I'm not worried. Yes, 4,000 is not "old" enough for mileage increase. Wait for 10,000.

When we were looking at new Sonatas last year. I was in favor of the V6, my wife wanted to stay with a I4 because of the gas prices going up. Our old Elantra was a I4 and I wanted to upgrade to the V6 and the bigger Sonata. Two new 2007 Sonatas sitting side by side at the dealer both of them were white. One was a GLS I4 and the other a SE V6. Prices listed were not that much different and on the stickers for the MPG, the GLS I4 21MPG city, 31 MPG Highway. The SE V6 20 MPG city, 30 MPG highway. After seeing this, my wife conceeded and we bought the SE V6. Now after 8 months and almost 11k miles, it is averaging 22 in town which is mostly short trips of 10 miles or less and 32 on the long highway trips, which are usually 150 - 200 miles rt. On our longer trips that were both over 1200 miles round trip, the mileage was better (except when I was pushing the limit and doing 20 over the speed limit coming back from the Blackhills). I know I am happy with the mileage and if gas prices go down, I might try the highest grade of gasoline to see if the mileage increases. A lot of people I know say the by switching to the higher grade of gasoline, while it is more per gallon, they get better mileage thus it offsets the higher cost per gallon as compared to the lesser grade of gas.

cmerica - while it is true that you MIGHT see some very mile MPG increase by switching to higher octane fuel (although, our car is designed to run at optimal efficiency at 87 grade gas), it is my opinion (and the opinion of many on here) that any possible gains you make by switching to higher gas does NOT offset the price increase per gallon. in some cars that may be true (cars that are designed to run better at higher octane gas), the Sonata is not one of them...

just my 2¢

bigdogbts,


When Sonatas get poor mileage, it's just about always because of driving habits.

Cruising above 65mph is one of the main culprits. Hitting 80mph daily is a real mileage killer, especially if the car is not fully warmed up.

Check your computer's average speed. My wife averages 38-39mph (I forget) and gets ~28mpg in her V6 on a 22 mile daily commute. If your average MPH is well below or well above that number, your mileage will probably suffer.

This post has been edited by bobad: Oct 5 2008, 08:33 AM

I have the 2006 V6 model.

According to mapquest I commute 35.08 miles a day ONE-way.
(Not including any pit-stops which are sure to happen.)

31.40 miles is highway

3.68 mi is "city" (Only 2.5 is "real" city driving (downtown Manhattan), The 1.2 miles to the highway from my house is mostly on a "county route' which is a 4-lane divided roadway with minimal stops.)

I average ~25 mpg but I can ALMOST get to 30mpg if I drive it smooth enough.

It is about 1.3 miles to the highway from my house and if I reset the mpg meter at home I will get no more than 20mpg getting there.
As soon as I get on the highway I can achieve over 30mpg and sustain 25+ until I get into Manhattan. From there I almost always see my mileage drop to the low 20's.

More or less, I think it is your short commute that hurts your mpg, but in the end you are still using very little fuel!!!! (I'm jealous)
I wouldn't expect to get more than 25mpg on your commute.
But if you commuted like I do you would easily be hitting 27-28+ mpg.


This post has been edited by dcjwlee: Oct 5 2008, 06:52 PM