2003 Sonata questions

My 03 Sonata with small 2.7 V6 engine is getting deplorable gas mileage. The
best mileage so far is only been 18.45 mpg. Vehicle has over 1000 miles on
odometer. This is 2 miles less per gallon then I was getting on a 96
Chrysler T&C van with a 3.8. I will be taking it back to dealer for repair
of this problem.

Also, has anyone noticed when first starting the vehicle after standing for
a few hours, the 2-3 up shift is delayed for the first mile or so. This
appears to have just started and it won't up shift until the rpm is nearly
3000. After a mile of driving the 2-3 up shifting occurs under 2000 rpm.
3000 rpm is too high for a cold engine. Anyone else noticed this problem?
Bob

 

My '94 Dodge Spirit with 2.5 in-line 4 gets 19 mpg. Your mileage looks fine
from my point of view.

 

You say small 2.7 V-6,is there a "big" 2.7 V-6?I don't think so.You don't
explain if the driving is in town or on the highway ,or both.18.45 mpg is
good for around town.I get 27 on the highway.There are too many variables
and differences to compare the mpg from one vehicle to another(size of
engine,weight,model etc.)I think you need to establish more meaningful and
accurate facts before you take it back to a dealer because you"think" the
mpg on your car is unsatisfactory.Think it over. Good luck.

 

First, where are you driving? City or Highway? If it's the former,
your numbers are just about right. Second, keep in mind that your
mileage will increase slightly after about 1500 miles and the engine
has been properly broken in. Third, the intake and exhaust systems on
Hyundai vehicles (especially on those with the "Delta" 2.7L engine)
are VERY restrictive. You can add another 0.5-1.0 MPG by installing a
K&N air filter and another 2-3 MPG by installing a larger-diameter,
less-restrictive exhaust system from the last cat back. Fourth,
Hyundai vehicles run VERY rich, to the tune of 10.5:1 (how do you
think they get away with that 10.0:1 compression ratio on 87 Octane
gas?). If you want to lean it out with a piggyback computer then you
can gain another 3-4 MPG.

The shift points are fluid and depend greatly on how heavy your foot
is. 3000 RPM is nothing, cold engine or not. I try to keep mine
under 3500 until the temp needle moves off of the peg and under 4000
until the temp needle passes the first line on the gauge. I wouldn't
worry about it.

 

Please don't top-post. Message rearranged to comply with Usenet
conventions.

Auto or manual? More precise odometer reading? My old Sable had
78,000 miles on it, so I could say it has "over 1000 miles" and be
correct.

Hyundai makes a 3.0L V6, but it's not available in the 2003 Sonata
according to their website. 2.7L could be described as "small" in
comparison to, say, the 3.5L V6 in a 2002 Nissan Maxima.

Estimated mileage for a 2003 V6 Sonata is 19/27 (auto) 20/27 (manual).
If the OP has an auto tranny and was doing city driving, the mileage is
fine. Also remember that the mileage will be worse until the break-in
period has elapsed (1200 miles for a Sonata?) and the rings and such
won't fully seat until about 3000 miles.

Don't forget personal driving style. If you're always flooring it at
stoplights, your mileage will be worse than if you accelerate gently,
and driving long distances at 80 uses more gas than driving long
distances at 70.

Aye.

 

My Sonata 2.7 with Auto tranny took about 10.000 Km (6000 miles) before
stabilizing mileage.
Now it is usually above 8 Kl/l (about 22-23 mpg).
Before I had about 7,5 Km/l (21 mpg).
Said this , the mileage depends very much from driving style and if in city
or highway.

Zotto

 

i think your cars transmission holds the gear longer when cold to speed up
the warming process to burn fuel properly and lwhen driven in cooler
climates, seen posts on thc.org and they sat same thing as you, but told by
duke on there that its proper for it to be doing that. Hes a hyundai tech in
southern On.

 

For city driving, 18 is about right; about 27 hwy. Avg should be about 22
for mixed driving.

About the 2 to 3 upshift, all hyundai autos seem to do that---I had a 2002
Elantra that did it in addition to my present 2004 Sonata GLS. It has to do
with the temp of the tranny fluid and the "adaptive learning" feature of the
Hyundai autos.

 

I have a 98 SOnata, and I get 21 MPG on Regular and 23 MPG on AMACO Premium.
Your mileage is not bad for a small V-8.

2MPG difference can be reflected in gas quality (some such as AMOCO burn
better) , type of driving. (if the van made long trips and the Sonata City
driving), seaonal driving (summer gas evaporates and often lowers MPG),
equipment on the vehicle, and even tires on the car can affect driving
MPG's.

 

Are you referring, when you mention the exhaust system of the muffler and
tailpipes???

 

When I said that the exhaust was very restrictive I was referring to
everything: exhaust manifolds, cats, piping, resonator, and muffler.
What I suggested replacing was everything from the last cat to the tip
of the tail pipe (this would be some pipe, a resonator, and a
muffler). This will give a slight power gain, as well as better gas
mileage. If you want to replace your exhaust manifolds with a pair of
3-1 headers and replace your cats with high-flow variants you will
gain quite a bit of high-end HP (at the cost of some low-end torque)
and several more MPG. Regardless of what you may replace, always make
sure that you get your pipes mandrel-bent instead of crush-bent.

Oh, I almost forgot, if you replace a cat with a high-flow model you
will void the 80K/8yr warranty on emission control. If you install
headers you will not be smog-legal in CA as there are currently no
headers for the Delta that are CARB-certified.

 

Have simular problem 03 Elantra 21mpg .call Hyundai said no codes no
fix!!!! Corporate never returned calls..
Have also 3.0 Acura CL 1999 getting 30 on hywy 25 city figure that ......
Will probably sell Hyundai by self buy a pre-driven Acura CL or TL both
good history AND MPG

 

I had the same problem with my Sonata 2002.

But now with my 2004, it's OK.