If gas is $2.5/gallon, and the Ridgeline get's 21 mpg (generous) and the Prius gets 50 mpg (average):
Cost for Ridgeline Gas Per Year: (30k/21)*$2.5 = $3,571
Cost for Prius Gas Pear Year: (30k/50)*$2.5 = $1,500
Price savings per year for driving the Prius: $2071
...and that's just gas. Tires, insurance, and general maintenance should all be cheaper. The big question is batteries...but I don't think they're that expensive and they're supposed to last a long time anyway.
$2.5k is a big difference, FI or not. One would REALLY have to value driving a truck to justify an extra ~$200/mo in operating costs.
Specifically when it comes to vehicle costs I'd say why are we hung up on truck vs. Prius when other more powerful possibilities are available?
Because OP is asking a specific question, and the answers are based on information he's already given us. Beyond basic math, I can read ;) Also, simple questions sometimes yield simple answers.
Why not drive less than 30K miles/yr to work
He states that he drives ~30k miles/yr for work. So, I'll just use common sense and assume he's not quitting his job anytime soon, otherwise he wouldn't even be asking this question.
Ask for mileage costs if you have to drive?
He already deducts his mileage I'm sure. Even if he did ask for mileage costs, he'd still realize a gain for trading vehicles, so this is a moot point as well.
Carpool with a co-worker?
Why would he be asking this question if he could do that?
Why I think this matters to the OP? If Pure Vulcan Logic was his only concern I'm going to say he can do grade school math and determine the Prius is cheaper so he would not have posted this question. Instead he'd be asking which fuel efficient car he should buy or simply posting how badass he was driving his Prius.
His question was should he trade for a Prius. So yes, It's obviously all he was concerned with. Another thing he seemed to be confused on was sunk costs. He is worried about the money he has already put into the truck, which is irrelevant to this decision.
If he drove less, there'd be less reason to own such a great vehicle to begin with. Why have an extra $10k tied up in a vehicle you hardly ever use when it could be invested and instead have a $3k car sitting around? I get what you're saying, $10k isn't going to make or break, but its still freaking $10k.
Then I would have an additional vehicle to use when.. towing, dogs, new construction jobs sites, bringing people mountain biking, camping, hauling tools/material to build a house, first dates ;) etc. My parents would also get a truck to use whenever they wanted.
Am I thinking about this correctly? Or is this a gluttony plan and should I only be focusing on having one vehicle?
If I could do it over again I would just buy the Prius and make it work. But that's not the case and just trying to make the best out of my current situation.
If your goal is FIRE and efficiency, owning a vehicle you don't use that's worth $13k is equivalent to having $13k stored under your mattress, except it's losing money to depreciation and inflation everyday. Huge waste of money.
Given the reasons you mentioned for owning a truck, I don't think you're fully committed to the idea of owning a smaller car. And that's fine, maybe a truck is best for you at this point in life. But if you can get by without the truck, I think you should do it from a purely financial standpoint.
Buying the Prius with the $12k in the bank wouldn't be as solid of an investment since, again, depreciation and inflation will erode the value of the (present day value) $13k truck. You're right, the return WOULD be greater than 1%, so it's definitely a great idea, I would just dig deep and find out if you really need the truck at all. Because obviously, getting rid of the truck
and getting the Prius is going to yield the greatest return on paper. Again, the fact that it's paid off is irrelevant to keeping it. All that means is you fully own the truck and will receive 100% of whatever you sell it for.