My GL with the 16" wheels and Michelin tires rides quite well.

Matt

Our GLS rides quite well on the 16" Michelins, but it is definitely
firmer than you're going to get on a traditional full-sized American
sedan. I have not driven an LX so don't know how it compares.

Highest we've gotten so far (according to trip computer) is 29.7 mpg,
this was on a trip driving 65 mph for the most part, using cruise
control. Current average is in mixed driving is 24.3 mpg. This seems
pretty respectable to me for a vehicle of this type, the Sonata is
hardly a tiny economy car. We found that the gas mileage increased
noticably after putting a couple of thousand miles on the car.

Ya, they're "sporty".  Not much in the comfort department. It's a normal
characteristic of low profiles. You give up quiet and comfort for
performance.

My Sonata V6 has the 16" wheels, and the tires have a pretty good ride and
are quieter over expansion joints. You may be able to trade even with
someone. Talk to your dealer and ask him to put you in contact with someone
that wants 17's. The 16's are still somewhat low profile, so don't expect a
100% improvement.

When you're used to riding in a land yacht, any sporty mid size car is quite
a comedown in comfort. You'll get used to it, and come to appreciate the
firm ride and precision handling that your Marquis couldn't come close to.

I went for a short trip last weekend, and nearly broke 30 MPG at 29.68. I
only have 2600 miles on the car, so I have no doubt I will get 30+ on long
stretches. You'll get there!

The lower the profile (aspect ratio) of the tire, the rougher the ride.
As you increase the diameter of the wheel, the tire sidewall
dimension, and aspect ratio,  must decrease.  The tire's sidewall
functions as a spring, just as does your suspension.

Early radial tires had an aspect ratio of 80, a.k.a. 80-series tires -
a rather narrow treadwidth on a 15 inch tire, for example.  The ride
was generally very good. As the ratio dropped to 78-series, 75-series,
70-series, 65-series, 60-series, 55-series, and so on, the sidewall
height continually became smaller.  There is less sidewall to absorb
the road imperfections, and certainly pot holes, etc.  Wheel damage is
much more likely with the newer designs with very low profile tires.
Tire sidewall technology has improved, but it doesn't change the fact
there is less "spring" available at the tire to absorb impact forces.

Yes, a GLS will provide a smoother ride than the LX.  That said, you
probably could find a tire that will provide a better ride than the
stock tires on the LX.  Your Mercury probably had either 15" or 16"
wheels with either 70-series or 60-series tires.  And, the suspension
system is certainly more supple (by design)  than the Sonata, plus the
wheelbase is longer, thereby providing a decent ride.

IMO, the move to larger wheel diameters has a practical limit.  The
giant wheels seen on some cars today, i.e. 20" or 22", are not only
impractical for every day use, but look stupid on the cars on which
they've been installed.

Have you checked the tire pressures? The cars are shipped with 45-50 psi
in the tires and sometimes the dealers forget to lower it to correct
operating pressure.

Did you check the air pressure??????????????

Never Forget!!!
http://www.september11victims.com/september11Victims/VictimInfo.asp?ID=2654

Although I do not (yet) own one, there is more and more data suggesting that
your better bet are the 16" tires and wheels.

I know how many of you feel about Consumer Reports, but when they tested
both the GLS 4-cylinder (with the 16" tires) and the V6 (with the 17"
tires), the higher profile 16" tires actually braked the car in a
significantly shorter distance and gave a solid level of comfort, while not
giving anything up for handling.

But since you have the 17" tires, if one does not like the OEM tires, your
only other choice may be to go to a reputable tire dealer and "trade the
tires in" on something you like better.  Most better ones will do that,
since they can always sell nearly new tires at a fair price (though you may
be a tad disappointed what you get for them).

One suggestion for a softer ride is a relatively new tire called the
Goodyear Eagle ResponsEdge.  It comes in your size and speed rating (V) and
looks to be a tire in the type of family that their Assurance ComforTred is.
It is VERY new (hence a relative unknown), but looks promising.  And among
the possible alternatives (not a ton with a 'V' rating) this may be your
best bet.

Just remember - a 'V' rated speed tire will always be firmer than the
typical tire they put on those big Mercury's (usually an 'S' or 'T' rated
tire.

Hope this helps.

Tom Wenndt

Thought they quit making solid tires in about 1909.  My LX with the 17 inch
wheels rides like it has solid tires. feel every pebble in the road.  do the
GLS's with 16 inch wheels ride smoother? Back seat rides like a lumberwagon.
I traded in a '99 merc Grand Marquis that got 30 MPG on highway with a V-8
for this thing and it rode smoother-quieter.  still trying to get 30 MPG
with this Sonata..Oh well I have it now and would lose a ton if I get rid of
it!

I know the Merc was a land yacht. but I put in over 20000 miles a year on
LOOOOng trips.I consistantly averaged 28-30 MPG on the merc driving
speedlimie+ 5MPH across the USA. One trip from San Diego to Chicago
averaged 29.8 MPG for the entire trip and this included driving in
Albuquerque, Flagstaff and Kans City. another thing about the Sonata: when
I called Hartford Insurance they upped my premium by $520 per year 'cause
this is a "sports car"!!!  The car is ideal, cute and classy for driving
to the grocery store, church and going to see aunt Nellie but a road car -
it ain't!  I can go see aunt Nellie in my Elantra and it rides better!

Deck, you have a problem. No one would expect the sonata to float like the
merc, but it is known to be reasonable supple........the lower aspect ratio
of the 17" tire is going to be more stiff than the 16".......but things are
relative. My lx rides quite smooth compared to my S60t with its monster
low/wide toyo's tires, but not as soft as my buick! (also toyo)

Check your tire pressure, and,........ your expectations..... Enjoy the
overall handling,  ride, and performance of the sonata. ps I'm getting over
28 mpg on the hiway now, 26 around town. pps If you got 30 mpg on the merc,
I'll eat my hat.....or its got really long hiway gearing......and 0-60 in a
minute!    ppps I'm not overly impressed with the michelins on my lx, maybe
you'll want to try something else once they are worn.

Deck,

Other posters have given good advice. I will not comment on the mpg
issue.

As noted, ride quality of any car with even a slightly "sporty"
suspension, 225/50 series, V-speed-rated grand touring tires and
17-inch wheels will feel quite rough compared to a Grand Marquis.
Anyone who suggested otherwise was less than candid.

If I may ask, why did you choose the Sonata LX for your next car after
a Grand Marquis? They're pretty far apart in most buyers' eyes; I doubt
too many new car shoppers look seriously at both. The Sonata that's
(relatively) closest to the Marquis is the GLS with the V-6. That has
16-inch wheels and higher, slightly narrower tires along with a
slightly softer suspension than the LX.

Maybe the change from RWD to FWD plays a part in it, too.

As others have said, if you want to spend the money, switching tires
and/or wheels might help. Here's a thought: A switch to 16-inch wheels
and 205/60/16 tires would almost perfectly match your OEM tire size, in
re speedometer reading. It would also come closer to the tire/wheel
size you had on the Merc. (Would also be better in the snow/ice, all
else equal, if that's an issue.)

Of course the car would handle differently, which is something to
consider....but that seems to be what you want. And this would not be
cheap.

Also you might want to bag the grand touring tires and switch to
regular all-seaon radials. At 205/60/16, you could try something like
Goodyear Comfortred or Michelin Harmony. The Comfortred is H-speed
rated and the Harmony is T, if that matters to you.

Tire shop clerks will tell you it's bad to buy a tire with a lower
speed rating than the OEM tire---which may be true in general,
especially for spirited drivers---but I don't think dropping from V to
H is a big issue, considering what you want out of your car.

(Also since the Comfortred and Harmony are high-quality tires. The
Harmony is supposedly a tad rougher and noisier, per tirerack.com
reviews. The OEM Michelins on the Sonata LX get poor reviews on that
site, BTW.)

Anyway, good luck. I hope you work things out so you get a ride you
enjoy with your new car.

Regards,
Eric M