3k trip what to do before the trip

There is no reason to change the oil before you go unless the next oil change would be due well before your trip is over.

Use whatever tire pressure you normally use, preferably someplace between the door jamb pressure and the sidewall pressure.

Fill the gas tank before you run out when you know you can still make it to the next open gas station. If you're a nervous nelly that fills at 1/2 -1/4 tank, keep doing that so you can stay in your comfort zone. If you normally run your tank lower, be aware that it can be a longer distance between stations in the West.

A break every 2 or 3 hours is reasonable, although I usually go at least 3 hours.

Carry something to drink with you, water is best. I prefer to not eat while driving, it's easy to stuff your face with too much food while you are just sitting there driving. You will also need less food while driving, 3 full meals will make you sluggish. Eat smaller amounts at least 3 times a day.

Pick some places/things to see/do on the way. Setting and meeting intermediate fun goals makes the trip seem less formidable.

 

The longest road trips I've done are ~860 miles, one way or a roundtrip of ~525 miles, each way. Oil change depends on whether you're due for it or might need it in the middle of the trip.

Besides checking your tire pressure, do so for your spare. Check that you don't have any low fluid levels. Make sure you bring a flashlight, tire gauge and electrically operated air pump along, in case you get a flat. Uhh.... as for gas, run it as low as you feel comfortable, keeping in mind how far the next gas station might be.

I'd bring along some fast music along w/audiobooks, podcasts or streaming audio (spoken and music), if available (e.g. NPR News app, Pandora, etc.)

 

1. Check all engine compartment fluids and replenish as needed. If any routine maintenance is overdue, have that done now.
2. Bring along windshield washer fluid.
3. Check the tires and replace if marginal. You don't need to have a high-speed blowout and be stuck on the side of the road.
4. Tire pressure should be checked when the tires are cold, before you have driven on them that day.
5. My personal policy is to refuel and take care of the car before I take my driving break. You'll have to decide what works for you.
6. Regarding when to refuel, I suggest you do so at 3 bars; frequently highway signs will show when you can expect the next gas station (of course, you are counting on that station being open...)

 

Don't worry about the car, but you need to take care of yourself. Sleep in a real bed every night.