Struggling with math, please help
 

I need some help guys.

Mrs. Spiff complained tonight that she's tired of stopping at the gas station so often and how long would it take a newer, more fuel efficient car, to pay for itself. So I got to work when I got home trying to bring the numbers together.

I have a cost to own spread sheet where I track costs on the cars and know that hers costs $0.12/mile while my focus costs $0.06/mile. Figuring that she won't do as well as mine on the next car due to a more traffic heavy commute I'm guessing the next car will be $0.08/mile. With the value of her car I think we are looking at around $8200 out of pocket for something along the lines of 2014 Hyundai (sister bought one this summer for ~$14,000).

Wife's car is 2005 Subaru Legacy GT that runs on plus/premium, gets a pretty consistent 20.X mpg and she drives 25,000 miles/year. Something like a Hyundai I'm guessing would get 30 on the low side and runs on regular.

I can't wrap my head around the math to figure out how long it would take savings to total $8200. How many miles will the new car have to drive before we ACTUALLY save money? How much would we be saving per month with a smaller gas bill? I'm tired and frazzled and know I should be able to figure this out but something just isn't clicking tonight.

Thanks for any help you can provide.

I get the same 20mpg in my Jeep, and 50 in my Prius.

Over a 200k lifetime, a Prius saves enough that that it will pay for itself even if you buy new. You can have a Jeep sitting and doing nothing but depreciating, and drive the Prius, and be financially equivalent to someone who owns a Jeep only.

Your fuel bill will be less than half.

Not sure I would bother going from 20mpg to 30 though. Get her a Prius. Hypermilers don't need hybrids, but for normal drivers they have bigger gains as they do most of the hypermiling for you.

4 cents per mile saved, $8200... 8200/0.04 = 205,000 miles. Divided by 25,000 miles a year = 8.2 years.

Thanks stubby! that's numbers I had come up with but as I over-thought it, began to doubt myself. Started trying to work in the premium/regular gas argument and just kept getting more confused.

Oldtamiphylie: don't think she'd go for a Prius, not sure I'd go for one either. Still not convinced that the total footprint of the batteries is offset buy the fuel savings. Thanks for the math on that tho showing how something that good can completely cancel out a gas guzzler like a Jeep....or a turbo Subaru

The battery in a Prius is only big enough to power the car 1/2 a mile tops. Yet it saves up to 50% off your fuel bill. The payback would drop to only 4 years.

I bought a Prius because like everyone else, I hated them. I'd suggest test driving one. It's never going to be my favorite car in the world, but sometimes that's exactly what you want.

It is almost never worth buying a different car to save money on gas. I have a similar situation, I drive 30k miles a year and average 25 to 26 mpg over a year.

Do you currently have a car payment?

Don't forget to look at the other costs like insurance and finance charges.

The battery in my Insight, and the older Prius at least, has similar total watt-hours to the 12v battery under the hood. It's more efficient to charge/discharge, lasts longer and can take higher currents, but honestly it's no "bigger" than the lead acid most people throw away every 3-5 years.

Anyway, if you're buying used, the battery is kindof irrelevant unless you plan on buying another one, and most outlast ownership of the car. Is a used Prius (or other hybrid) significantly more expensive than an equivalent used non-hybrid?

~

If I were buying a car in the $3-5000 range (for a non-enthusiast), the only ones I'd really consider would be a Prius or Fit.

If you really shop around, you might be able to find a used Volt close to 8k. While running on electricity, you can expect around 2 cents per mile for the first ~35 miles, and you'll have far lower maintenance needs since the ICE won't be spinning the vast majority of the time.

Lots of people hate Prii. Considering all of the vehicles on the road that are unnecessarily large and powerful, it seems like making a statement is more important than their bank statement. There are other hybrids, but whenever I did the ROI calculations for adding the hybridization, it took a ridiculous number of years. I used to read that it cost $4,000 more. Forbes says $3,000, and most hybrids cost more to own than their gas-only counterpart.

I hope the Lexus LS 600L would not be under consideration, that uses hybridization for speed, with only token fuel economy improvement, but costs $118,537 to own over five years, while the gas-only version would be $90,359. It "would take an owner – and his or her descendants – 151 years to recoup the added up-front cost entirely at the fuel pump." https://www.forbes.com/sites/jimgorz.../#17be6e865d7c

According to Vincentric, only the Toyota Prius C and the Ford Fusion Hybrid save over five years, by roughly one percent each.

As long as the interest rate is at least 1%, I think it makes more sense to purchase the gas equivalent, and pay it off a little sooner. Since there are not non-hybrid versions of the Prii, they compare the C to a Yaris, the " " to the Corolla, and the V also to the Corolla. If you prefer to compare the V to the Camry, the V has an estimated $33,532 cost to own over five years, $29,679 for the Corolla, and $30,361 for the Camry. http://vincentric.com/Portals/0/Mark...ust%202016.pdf

They estimate fifteen thousand miles a year. I do not know how twenty-five thousand yearly would change that, 2/3rds more gas savings, but also a greater depreciation.

I made my own table based on their table:
http://ecomodder.com/forum/attachmen...1&d=1513527577

Time and age are the great equalizers though. After a decade, luxury cars, hybrids and econoboxes all cost about the same.

Also, I do not know how buying a car a few years old affects the various factors I mentioned.

What kind of Hyundai are we talking about? Ioniq? Otherwise, forget it. Lots of other options out there.

Have you considered putting an auxiliary tank in the car she has now?

http://ecomodder.com/forum/member-fr...3-100-0884.jpg

The problem is that she is not transporting enough gas?!

If you two pay for brake service, that alone will offset the cost of a new hybrid battery every +/- 250k miles. The gas savings is just icing on the cake.

If you service your own brakes, you can also maintain you hybrid battery after it needs service for not much more than you pay for oil changes if you're OK pulling it every year or so, or for maybe $1000-$2500 (low mileage/age salvage pack to a factory replacement) if you want to set it and forget it for the next ten years.

Have you thought about a used plug-in Prius (~$15k) or a Prius Prime if you can use the full tax credit (~$20k+)? Both of them should be faster/get better mileage than the plain gen III hybrid and IME will be more reliable.

I miss my 2005 LGT.

I don't miss burning more than twice as much gas to get anywhere, but it was awesome.

But buying a car before you need one is a bad move, efficiency-wise. Stopping less often or paying less per fill up isn't going to outweigh buying a car too soon- and selling a 12 year old car isn't going to make up the difference. Tell her to enjoy the boost while she's got it and then make a less power hungry decision when it's time to ditch the car.

I really miss that car, though.

Good insights guys. I'm thinking a Hyundai Elantra, Honda Fit, maybe Camry or Echo, Focus or Cruz/sonic. Needs to be 4cly and naturally aspirated is really my only concern. Her old 2008 Impala had a dieing trans but that 3.5L v6 was good for 30mpg with her commute, just really hate working on V engines in a FWD orientation.

I do mostly all our own work except for big jobs like her timing belt.

With all the Prius talk and floating around Craigslist looking at used ones; I might consider one when it comes times to unload my wagon due to subframe rust.

Friends don't let friends drive Pruisiz. Think about a turbo-diesel.

Not sure I trust her enough to make sure she gets diesel and not gas....maybe with a really big post-it on the dash she'd be ok lol

Did you hear that smrtcars have something that looks a great deal like a fuel tank door on the opposite side from the fuel tank door? You forget what side your tank is, "Well, this is weird..." pump gas into what you think is your fuel tank. Hang up the nozzle, go to start your car, and enjoy the firebomb!

I drive a Prius plug-in and love it. That said, I'd look at a Fusion hybrid. It's my favorite rental car at the moment, and I've mentioned it in several posts. I've managed to get 45 MPG without trying, and it's a smooth, quiet ride. No idea what these cars go for, or how long they have been around on the used market, but I imagine they depreciate faster than the Prius since they aren't as widely sought after as an economy car.

6 or 8 cents/mile to drive a car? That's bad math right from the start. The average new car costs over tens times that much -- more than SIXTY cents per mile to operate. The biggest piece by far is depreciation, so you can knock that number down significantly by buying used. Also, driving higher mileage per year will reduce it a bit as well. However you are never going to get into single digits unless you drive fully depreciated cars, do all of your own work on them using stolen parts, and drive uninsured.

Here's the latest figures from AAA:

http://exchange.aaa.com/wp-content/u...s-Per-Mile.png

I feel a fuel cost savings is not accurate enough, you need to calculate the total cost of ownership on both including new fuel cost and see how it works out.

say 15k miles a year this is all hypothetical:
monthly fixed cost:
insurance-50
payment-150

annual cost
registration-120
inspection-40

non fixed
Maintenance
oil/filter/air/-$7.5 monthly
fuel-200 monthly
wear n tear lets say tires cost $800 and last 50k miles-so $22 monthly


this is all very simple but all you have to do is something similar and which ever car cost less =/- better resale after 5-10 years etc.

the above car cost $5314 per year or .35 cents per mile IF you drive 15k per year etc.

Im not sure how AAA came up with those numbers because that's crazy. I could see those numbers if you paid a dealer for oil changes every 3k miles and for every other "SERVICE" they try to pin on un-informed customers....

My 1999 f250 diesel which cost $375 on even years and $425 odd year for registration EVERY YEAR CA takes that from me, takes 16 quarts of oil every 5k miles, gets about 15-15 mpg with $3.30 a gallon cost me .55 cents per mile to drive this year. that's including my monthly payment, and collision an comp insurance coverage with very high amounts etc...

If you purchased that truck for $40,000 new on the lot, put 15k miles on it per year and it lost $4,000 in value for the first 5 years (leaving you with a 5 year old, 75k mile truck worth $20,000), that adds almost 30 cents per mile for the first 5 years. That doesn't take into account your monthly payment, insurance, registration or any maintenance.

My Insight, on the other hand, was worth $3,000 75,000 miles ago. It's probably still worth $3,000.

EDIT: Another way to look at it, if you paid $40,000 for it new and plan to drive it into the ground (let's say 300k miles since it's diesel), it's an amortized average 13 cents per mile until the scrapyard takes it. The earlier miles cost more if you ever intend to sell it.

It comes down to comparing total average annual cost of operation per year over the life of the vehicle. Fleet managers and accountants are familiar with the calculations on economic life. The other half of the decision making process is prioritizing value management or quality requirements. Ask what it is that makes operating a vehicle useful enough to spent money.

I had just read the headline, and I thought it was an electric; but it's the bug that Xist described:

jalopnik.com:Smart Car Explodes When Driver Fills Wrong Hole With Gas But I Blame Bad Design

I find irony in the name of the car company, especially in light of that story.

I've been very sleepy and briefly opened the wrong "filling" cover on my Prius plug in after pulling up on the wrong side of a pump island. Hard to imagine ignoring all the clues that you're doing it wrong.

I wonder how much fuel she pumped into the intake before the nozzle clicked off? I'm surprised it didn't hydrolock the pistons and prevent it from turning over in the first place.

You can easily be ahead getting a used car. The LGT is worth $5-7k around these parts via a quick look on craigslist.

I purchased my 2014 Mirage with 77k miles on it for $3500. I'm not sure she'd be comfortable with that small of a car, or with that massive of a horsepower drop lol, but there is one option. Most in the area go for about $6500 - $8000.

Personally, I'd look at used Prii though, 2nd gen, 2007 - 2009 model years. My in laws got a really nice one about a year got for $6k. Looking again on the local craigslist, these go for about $5-7k. You could do an even trade and start saving immediately. She won't even have to try to get 45+ mpg I bet, and they're rock solid reliable.

What is an air intake port and what Apple Genius decided to make one look like a fuel door?

Engineers! Ha! :p

$11k

https://images.craigslist.org/00L0L_...tP_600x450.jpg

https://philadelphia.craigslist.org/...396838162.html

How many miles does your wife drive in a typical day? I'd get a Chevy Bolt if I put that many miles on a car in a year. Not only is electricity where I live $0.02/mi, but there are practically no maintenance costs except for tires and wiper blades. Owners describe it as being quite a fun car to drive due to quick acceleration and firmer suspension.

BTW, my signature has a cost of ownership spreadsheet in it. You can input values for a gasoline vehicle in one half of the spreadsheet and compare it to an EV on the other.

I have a clickable link in my sig if anyone's wants to dispute my cost of ownership please critique my formulas. The "cents for mile" is strictly for fuel, not the rest of the car ownership. All cars will come with their own maintenance issues and all so I'm not worried about those. Was just running the exercise to see how long it would take a more fuel efficient car to pay for itself if we got her a new car. The plan would be to buy a used car cash and sell the LGT to offset the cost. Figure $6,000 to sell it, buy a car around $14,000 and see how long it would take to recoup the $8,000....which is a really long time for a car costing approximately 8 cents/mile.

I need to look into the fusion but my "old school" nature likes the idea of just an engine, trans and wheel and no extra stuff to gum up the works. As time goes on it looks like we are destined for hybrid drives and turbo engines so my idea of simplicity is clearly outdated and fading away.

Plug in EV would be nice but we have no where to charge outside at out apartment complex. Her work has like 2 stations so if they are taken for the day she's got no charge to get home and back.

If you can sell the LGT for $6,000, a high mileage Pip (it's a base) is only ~$7000+. You would be break even after ~30k miles, and be ahead after that, assuming you're paying $1.90/gallon.

https://www.cargurus.com/Cars/invent...ting=193701370

Or spend a little more and get a lower mileage/cleaner car. Break even would be at ~120k miles.

https://www.cargurus.com/Cars/invent...ting=193799025

Gen I Volt!

If your wife gets a charging spot, that's gravy. If not, the car gets pretty decent fuel economy. I've never driven one, so no idea if they are any good.

I'm in the same boat now in that there is no way for me to charge at the apartment. My parents are only 15 minutes away though, so if I got a Bolt, I'd just charge it at their house every couple weeks.

Our family is in a similar situation. Our 2003 Dodge Grand Caravan is a V6 with 136,000 miles, just in time for the transmission to go bad soon. It is 2 miles to mother's night job, the only two children still at home take the bus to school, and the shopping mall is 10 miles away on the other side of town. I am the only cyclist in the family. Holiday visits require 3-4 hours on the interstate with no direct bus connections. My wife and I both can drive a 5 speed trans.

Very nice spreadsheet and record keeping. Your Excel skills exceed mine.

A numbers guy like you will make a good financial decision based on needs and wants.

Thanks, you're welcome to steal the formulas if you want. A quick Google on "if/then" formulas had me off and running. It all started back with my old Saturn when people would rag on me for driving an old car, I wanted data to back up my "when your car is as cheap as mine we can start comparing luxuries"; so when I bought my Focus I started the spreadsheet, and copied it for the Legacy. Since I buy all the parts for the cars it's easy to keep track, and my wife has been pretty good about giving me gas receipts and writing the miles on them for tracking purposes.

I guess she's dropped the idea tho, she's decided that we'd be better off keeping the money in our pockets than into a newer car. My Focus will succumb to rust soon and maybe I'll look into the Fusion or Prius for a replacement...the only thing the next car needs is an automatic trans so both can drive both cars in case 1 needs service...I'm not happy about it but she just doesn't like driving with a clutch.