Which is better for a long trip, owned car vs rental car?

That would depend on what your particular priorities are, and as a
corrollary, the general condition of your own car.

If your own car is in robust condition, then driving it will save you
all the cost of car rental & whatever extra insurance the desk clerk
suckers you into. On the other hand, if your car isn't in tip-top
shape, then pushing it on a long haul may cost you a considerable
amount after the trip is over, in the form of repairing/replacing
whatever reached critical age during the trip.

A few years ago I took a longish road trip of a couple of weeks. The
car I owned at that time had well over 150,000 miles on it, and needed
some peripheral engine component replaced every few months. It was
very reliable for getting me to work each day, but I certainly wasn't
about to drive it several hours each day for days on end, only to be
putting it into the garage immediately thereafter, or even possibly
needing to replace it altogether. So, I rented a car, which took a
great deal of concern off my shoulders. I was able to just relax and
enjoy the trip.

For the 2004 election, a friend of mine was traveling several hundred
miles to Ohio to monitor polling facilities. I urged her to rent a car
despite the fact she had a nearly new Saab that was carefully
maintained by her mechanic father. "If it breaks down," I said,
"They'll bring you a new one." She pooh-poohed my recommendation and
she set out with another eager young poli-sci major.

Four days later she returned. The republicans had engaged in a number
of underhanded tricks and she had gotten in a relatively minor car
accident. She had to leave her car there, rent a car to come back
home, keep the rental for use, and then fly back to Ohio to retrieve
her car in three weeks after it was repaired.

A few days after she sheepishly related the story, Saturday Night Live
rebroadcast an episode with Mike Meyers doing his "Middle-aged Man"
skit and we caught it. We howled as Meyers counseled a young couple on
various matters and wrote our own coda to the routine involving
renting a car versus using your own.

Get a good deal on a rental and save your on car. Costs to operate run
a good 50 cents per mile for your car and you can often do better with
a rental. Get a nice, comfy car with satellite radio and you'll be in
heaven.

For a long trip it is always better to have a own car.because u can
get it ensured and in case of any mishap,  can clame the loss. and
also it reduces the tension from us. because there is always a tension
for having some damage in the rented car. so my sugestion is always to
have owne car for a long trip...
Bye
Have a nice time..
-Pratik