How many mph and rpms can my car sustain if I'm going to be driving 12 hours non stop?

So I have a 2003 Honda Element awd 4 speed automatic. My car has been serviced and has been mechanically inspected. I just changed the oil 2 months ago.
The thing is me and a co-worker of mine are planning do do a cross country trip from new Jersey all the way to San Diego, Cali. This is going to be my first cross country trip and I have never attempted doing this in my life. The longest trip I've done was traveling from NJ to Miami Florida with my dad driving a performance car(Infiniti g37 that was just lease off the lot). However, my biggest concern is how will my truck keep up with traffic in some of the state's I will be traveling into? I mean my state the speed limit is typically 55 mph but I know that in most of the western states, the speed limit is around 70(I believe) but in some western states I've heard that on some highways, drivers cruise really fast as much as 80-100 mph. My concern is can my car keep up with traffic at these speeds for long durations at emperatures as high as 90-95°? This trip is estimated to take about 4-5 days along with the resting stops we will be taking but if we going to be driving for at least half the day, what speed cany car comfortably cruise at without having to worry about wearing the engine and transmission and still last me 350,000 or more miles?

You drive at mid-range of the rev counter, usually around 3000rpm.
Speed limits are limits not targets.
You will probably wear out before the car. Be sure to check oil water and tires daily.

I would guess 100 mph - but the cops will stop you; and an empty gas tank will stop you. {Texas and Wyoming are 2 of the few states that allow high speeds - but you do not have to keep up.} P S If you are in such a rush, I suggest you fly.

Well don't worry to much.avergae freeway speed in cali is like 35-45… You will be just fine. And alot annoyed by the traffic… And welcome to the best coast…

Your car can easily go as fast as the law allows until you have to stop for gas. I wouldn't recommend going 80-100 mph just to keep up with traffic, though. The highway patrol will see your out-of-state license plate, and pull you over. Stick close to the speed limit, and you will be fine. At highway speeds, your engine should run at between 2500 and 3000 RPMs. A decently maintained car should be able to do that for hours on end with no problems. Be sure to check your tires and fluids whenever you stop.

First of all, check all your fluids and rubber before you set off and check your tires and oil before you set off again after each stop. Secondly be aware of the speed limit applying to the road you are on and don't exceed it; as Percy says, they're a limit and not a target. Again as he says, somewhere in the middle of the rev counter is usually a good cruising rate.

You don't have to keep up with the locals, let 'em past if they want to go. You choose a speed that both you and the car are comfortable with, it's not a race. Just don't be the slowcoach holding up a queue of fuming drivers, that does no good at all.

Don't let your fuel get too low, in case you come across a stretch with gas stations few and far between.

Make it a cruise that you enjoy, not high-speed thrash, and both you and the car will be fine. In fact, it will probably do the car good to have an extended run, far better than short trips where it barely warms up.

Whatever the rpm is when you drive the speed limit.

If traffic is running above LEGAL speeds, you don't need to keep up. Maintain a highway speed that you are comfortable with.

Your 15-year-old Honda will be fine running at LEGALLY posted highway speeds. OR it will blow up in the middle of a freeway during local rush hour. There's no way to tell for sure, but if your car is well maintained, and you check oil and fluids every time you stop for gas, and top off as needed, the odds are in your favor.

This troll again. Kindly **** off

2003 Honda Element troll (aka 98 Nissan Altima troll) strikes again.

West Texas is the only place where 80 mph is the posted. Way too fast and I'm a professional driver. As you are new to long drives, set the cruise for the posted limit, except there 70 max. Stay in the right lane except to pass ( every where). Fuel up at or before 1/4 tank. Both get out and walk around, pee and keep hydrated as you go west, the air is dry and you can get sick. Drive daylight hours for best vision, and don't rush. Get there alive. Check fluid levels before leaving for the day. Buy a couple of quarts of oil before the trip and a gallon of your coolant, that way you won't be paying gas station prices if you do need it. Keep windows and lights clean, drive with head lights even in the day time, safety!