Another few things to consider. You KNOW the vehicle you have now, you don’t know this SUV, you don’t know what repairs have been done or need to be done on it, while you do on the vehicle you currently own.
Also, SUVs tend to be a higher insurance rate, and newer vehicles generally cost more to insure than old ones. Many companies will require you to pay the first month of insurance up front on a new vehicle, even if you are already insured with them. They will also run a credit check, do you want anyone running a credit check right now? Remember your credit rating generally goes down as you pay off debt, which equals higher insurance rates. The more credit checks ran the lower your rate goes, and they will run a credit check for the new loan as well.
Plus then you have to consider the cost of sales ads to sell your existing one, excise tax and tags for the new vehicle. If you have to replace any parts or tires on either one, which is going to be more expensive parts wise? There is a lot more to compare besides gas mileage and current loan rates.
Speaking of loan rates are you certain you can get another loan and if you do what will the interest rate be? You definitely don’t want to go up in rate.
Sorry if I am being a downer, but I am a math nerd and if you are going to run a cost comparison, you need to consider all the costs.
When I was delivering flowers I put items in the seat and floor board to level the back seat out, including a piece of plywood and it made a nice flat surface to haul the thousands of dollars worth of fragile flowers. Would doing something similar make it easier on you?