Im also a math nerd. Ok, so you are considering 24k for a sienna with 80 k miles. Compare that to a new one, say, my 2023 Sienna which will likely last 200,000 miles, and so will yours. (Actually the hybrids tend to outlast and have less maintenance than the ICE in many vehicles. Why? Because the electric motor is propelling your car a significant portion of the time. If its 10 percent, then a 200,000 mile Sienna has the equivilant of 180,000 on the engine with the hybrid.
Back to the example. My Sienna was 45k. Divide that by 200,000 miles (estimated useful life) and you get .225 cents per mile of your car which is "used up" each mile you drive.
Now, work your's. Again lets assume you get 200,000 miles (no guarantee..especially when you often have no idea how the last guy maintained the car). This means you have 120,000 miles left to go of useful life. 24,500 divided by 120,000 miles is 20.4 cents per mile. Hypothetically this suggests the used car is a better buy than the new one, but, this does not consider some very important factors:
1. Your new car will have a warranty, the used one will cost more if you buy it, and probably be inferior to the new car warranty.
2. You will get much better fuel economy with the new car. If both cars get epa mileage, then the sienna hybrid will save 2381 gallons of gasoline vs the 2016 gas model.
At 4.00 per gallon that is 7.9 cents PER MILE less for the hybrid in fuel vs the ICE sienna.
3. Remember, about 80 percent of your repairs will occur in the "last" 20 percent of the cars life. Very often this means it costs more to keep that old jalopy running than to replace it. A dead, not running car is not worth much on trade.
If you add the subtract the fuel savings (7.9 cents per mile) from the original 22.5 cents per mile (new), then the new sienna will cost just 14.6 cents a mile (equivilant) after the fuel savings is deducted, which is far less than the 20.4 cents a mile on the 2016 Sienna.
For that reason, the 2016 "sounds" cheap, but, when you run the numbers, its no good. I can also tell you there is great peace of mind, driving a newer car in warranty. If it breaks, I call the dealer and tell them to fix it under warranty. Its someone else's problem, not mine. Generally a near new car is highly less likely to fail than an old clunker.
I used to buy cheap cars and fix them for decades. I bought a $400 Chrysler and drove it 2 years. But, Im done working on them..I dont even change the oil any more. I served my time working on old cars. Im retired now, and a car is "to serve my needs", and "its not my job" to get a second job to "feed" a car. I would not feed that 2016 money. Instead, you can consider alternatives, especially if you dont need that much room. Corolla Cross is very interesting, new, at not much more than 24,500. You can redo that math on each car you consider. Its not hard. Edmunds "TCO" True cost to own is usefull, too, for comparison.
Cost of Car Ownership - 5-Year Cost Calculator | Edmunds.com
While this is an unusual market that will unlikely go on forever, the least expensive way for me to drive is to buy a new sienna and trade it in about every 2-3 years on another new one. Right now, a 2 year old Sienna is worth "very close" to what a new one costs. This means zero depreciation. Beat that!
