LA to NYC via the south

Hey me and my friend are from northern ireland (21 and 22) and we have talked about doing this for some time now and have started putting pen to paper and working some stuff out.

Firstly our route - Starting in LA we aim to spend about 21 days total travel from the UK back again, so this gives us around about 19-20 days to get from LAX to JFK. We have a rough plan put down on paper, ill give u a brief plan -
LA for 3 nights to see how life is in american.
Then on to the Mojave national preserve along the way to Las vegas, couple of nights their just to live it up.
From vegas we plan to head to the grand canyon aiming to finish in Albuquerque that night.
From there on to Oklahoma city maybe spending the night.
Then down to Dallas aiming for Houston (night over in both or maybe just Houston depends)
On to New Orleans for a night
Then a hell of a drive to Orlando for about 2 nights
After this we sort of hit a dead spot up threw south and north Carolina until we finish our trip with a few days around Washington and New york.

Id just like to ask for some sights along the way or places we should visit, we have a few days spare at the moment they shouldn't be to hard to fill in Im sure.

The main reason Im writing this post is to do with car hire in american, we have looked a few websites and we see pretty much all of them have surcharges because of our age and additional driver charges.
We had planned to keep the main expense of this trip to a minimum (flights, car hire, fuel and food) so we could have plenty to spend as we wished.

At the moment we aimed to spend around 4000 pounds (6000 dollars give or take) in total, So we took out 1500 dollars for flights priced and checked.

Around 45 dollars a day on fuel (this is a bit iffy) which is about 800 dollars for 18 days driving.
Looked on some maps and work it out to be 4000 miles to get to the main places we need to hit but that dont take into account the places we will get lost or spend off the main route.

Accommodation we set a target of no more than 40-60 dollars per night while on the road (18 days maybe less) because we will have prepaid our hotels in LA and NYC.

Leaving Food we hoped to not spend more than about 30 dollars per day less some days more on others.

Car hire we aimed to have for about 600 dollars but after we found the charges for our age and that number was set to increase by around 50 dollars per day (2x25 for 2 drivers under age). Any advice on companies that favor the young? We need a pretty decent sized car/SUV for about 18 days max with 2 under 25 drivers that we can pick up in LA and leave at NYC.

By my maths that leaves about 2200 (again give or take) for car hire and money spent on tours and sight seeing etc.

Im would like your guys advice on how to save some of this money or were to spent extra to make the trip a total success. We don't really know the cost of "living" over there so some info would be much appreciated.
We haven't taken into consideration road tolls or any other charges that may or may not apply.

That turned into a bit of a wall of text but there is so many questions that need answered and made 100% sure before setting off this july.

Thanks Ben

Welcome to the RTA Forum!

I think that's a pretty solid plan.

Car rental is the big one, and it won't be cheap. There is no single company that's best, although based on what I've seen from some other visitors to this forum, many times you can find the best rates by going through a broker based in the UK/Europe. Shopping around is key, and getting a final number there is going to solve a very big piece of your budget picture. Going with a larger sedan will likely give you a much better value than an SUV.

Your hotel average looks reasonable, but you might be a touch on the low side. It will probably work out pretty good on average, but there will likely be a couple nights you have to pay a little more.

For food, you're going to have to do a lot of your own cooking to keep to your food budget. You might want to look at getting some sort of grill, camp stove, or a small indoor electric device like a foreman grill so you can have a hot meal without paying for restaurant meals. Eating out every day will break a $30 a day budget (unless you're talking $30 each.)

I would recommend you spend time searching the forums and the Roadtrip planning pages in the tool bars above. The Map centre will let you create different routes and find what attractions are along that route within a 100 miles. I agree that your outlined plan is a good base to work from but by the time you have added a little time in Washington and New York your trip is very biased to driving from City to City with little time to spare elsewhere. This is highlighted where you mention going from Vegas to Grand canyon and then on to Albuquerque for the night. Las Vegas to Albu is a good 10 hours of driving and it will take 3 hours just to drive through the Grand canyon South rim before you get out the car.

When using mapping programs it is worth noting that there estimated drive times are always over optimistic. They don't expect you to stop for food, gas and rest and expect the roads to be empty for you to continue on your way without any delays for congestion or construction, what a perfect world that would be ! Add 20% to the times to get a more 'real world' idea or just figure that you will average between 55 and 60 mph on main highways over a day's travel.
At the moment your trip will need around 8 day's of dedicated driving so you can work from that.