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I recently purchased a Sante Fe with 70.000 miles on it. I don't think it is getting the gas mileage it should. I calculated approximately 17.5 mpg. Oil is Good, Air Filter is new, Changed the plugs and properly gapped. What else should i do to possibly improve my gas mileage.

Thanks
 

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:00000732:

In mostly city driving (less than 15% highway), I get between 17 and 18.5 mpg and I've found that the 10% ethanol blend most states use really hurts fuel mileage. I know before Oregon made the switch I would consistently get between 19 and 21 in the city! Now I struggle to pass 22 on the highway.
 

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Thanks, yeah I know the ethanol has definately played a role, so I will probably try the stabilizers that stop the phase separation and see if that helps. The fuel filters on these are non serviceable right? I may try cleaning out the throttlebody and getting a cleaner that will get in and clean out the injectors. Has anyone ever used the sea foam treatment?
 

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My 2005 gets 12.5l to a 100km converted that is about 19 miles per gallon, far from the 28 blue book states. I will be changing my plugs and fuel filter soon so I`ll check if there is any improvement and post if any. :3gears:
 

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Actually klixie, I just remembered I took out the air intake silencer box and that did help ever so slightly. Not to mention it sounds just a little bit louder, especially at WOT.

Directions are here but I didn't really follow them as I wanted it to be easily and 100% reversible. What I did was take the intake apart and took the main hose portion to Home Depot where I found a rounded pipe end that was just slightly too large to fit the opening for the box. We took it home, lubricated the pipe end with car wash soap and slid it in. That was a year or so ago and it's still in and the car still runs great.
 

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Your gas mileage sounds about right. My 05 4WD got 14 in the city and my 06 FWD got 19 city. The 2.7 is not fuel friendly but it will last a very long time. It's a durable, proven engine.
 

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Ok so since I changed the plugs, and ran a little lucas fuel injector cleaner through it, i got 18.5 miles on this tank. I took the silencer box off yesterday and we'll see what that does. I just filled up today, so it'll be a week before I know.
 

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Hi, I just bought a 2003 SF, 3.5L, AWD, and I'm getting 10mpg in town. No joke. I don't drive fast or rev the engine much. I'm thinking this thing should be getting more like 16 or 17. Please help! And I'm not a car-nut, so if you can dumb it down, as much as possible. Thanks!
 

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:00000732:

Here's a list of things to check. I'll try to make it as easy to understand as possible.

- Check the oil and if it's anything other than a golden brown, have it changed.
- Make sure the tires are pumped up to at least 30 psi (I run 32 to 35 psi)
- Check the engine air filter and see if it's dirty.
- Your fuel injectors might also be dirty in which case they'll need to be cleaned or replaced.

If you can afford to take it to a trustworthy mechanic or Hyundai dealer, I would. 10 mpg is way down there and I think you might have seriously clogged injectors or maybe a stuck brake caliper which is creating drag and causing the engine to have to work extra hard.

Hopefully this is of some help to you.
 

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Discussion Starter #11
10mpg is horrible, is there a rough idle, how many miles are on it, sounds like it could only be running on 3 cylinders or something. Could be the clogged fuel injectors as well, but definately get it checked out by a trusted mechanic.
 

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My '04 SF 3.5L, 82k miles, is giving me about 27mpg highway (40 miles one-way to work, 90% highway). We've only had it about 5 weeks and as our old car (95 Mazda Protege, got 44MPG!) and our '05 Elantra were both 4cyl, having power under the hood with the SF got me to be very easy on the throttle from a stop which seems to help. The one week the wife took it every day to work she only got about 21mpg but it's a shorter drive (12miles) and she tends to just step and go.

So I'm happy with what I get for mileage. We knew going to a larger vehicle with a 6 cyl from the Mazda meant using more gas but the SF is a nice vehicle and we really wanted a 4WD/AWD for NH winters and just a bigger vehicle to haul our camping gear in.

Sam
 

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I was just wondering, if I wanted to clean my fuel injectors, what is the best method and chemical to use. I am also debating whether the $60 a piece replacement of them all would be a better route. Of course if i go to the factory it will be alot more a piece. I am hesitant to use the injectors at the auto parts store after a bad experience and think it may be better to give them a good cleaning.
 

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My '01 2.7 AWD gets around 19-20 MPG in town and mid-20's in pure highway driving. I have seen as good as around 27 MPG. Considering it was a significant step up from my old '96 Kia Sportage, you won't hear any complaints from me!

You might try getting a pint of Seafoam cleaner at Wal-Mart, Advance Auto, or another car parts place and putting it in a full tank of gas. It's a good fuel system cleaner.

One of my future projects is to remove the throttle body and give it a thorough cleaning out and, at the same time, use the Dremel tool and some fine sandpaper to smooth any rough edges off the aluminum casting that might cause turbulence of the air flowing through it. Can't hurt.
 

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Over here in UK we have a wonderful product for cleaning and I MEAN clean. Over the period of a tank and half the difference is astonishing. Carbon deposits vanish, to the point where you can see the serial numbers on the piston crowns. Don't laugh, go here http://www.fueltechexperts.com/. Enjoy. Glyn.
 

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Recently bought a 2002, 136,000 miles, 2.7 v6
first thing I did was flush the transmission twice
what a difference
used Amsoil synthetic ATF
Combined highway and city 19 - 20 mpg
Highway only 21 - 22 mpg
perhaps it's not the engine but the slush it has to spin in - my mechanic says to double flush the transmission every 90,000 miles or if the fluid turns less than bright pink.
worked for me!
 

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QUOTE (jsentgeorge @ Jul 12 2010, 07:59 PM) index.php?act=findpost&pid=341219
Recently bought a 2002, 136,000 miles, 2.7 v6
first thing I did was flush the transmission twice
what a difference
used Amsoil synthetic ATF
You are taking a BIG chance using third party transmission fluid!! Just because it's Amsoil doesn't mean it's best for your car's transmission.

These message boards are full of stories from people who used non-Hyundai fluid in their transmissions and ran into very expensive problems a month or two or three later. Look at it this way: The people who made your car knew what they needed to make it work right.

I consider others' mistakes a lesson for me. I would never use anything other than what the factory recommends in a case like this. It's your car. Take your own chances.
 

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Well after replacing spark plugs and cleaning intake and throttlebody and running fuel system cleaner through my car and after a few tanks I am still getting approx 18 mpg with about 20% highway or so. I guess this is what I will be expecting unless I break down and just replace the injectors or go get them cleaned out.
 

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I recently joined Fuelly and have noticed an interesting trend; the lower the fuel level is when you fill up, the better your mileage is. Now I'm not sure if this means that the car gets poor mileage with a full tank or if it's just a fluke but it is interesting.

Oh...I went to the beach yesterday and on a mostly highway tank (with lots of hills), I got just a hair under 23 mpg.
 

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When I use injector cleaner in my gas, I add the bottle designed for a full tank to 1/4 tank of gas and then drive constantly until on the empty. If you park the distillets will flash off and do no good. What you are adding is petroleum distillets which flash off real quick. THe injectors need to have the fluid thru them in order to clean. Try this and see if works for you.
 
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