Gas mileage formula Options

[impala454]

So I was reading on some site the other day, some dude had done some calculations for himself and figured out that his break even point for parking his current vehicle and getting a high mpg car for daily driving was at around $5.00/gallon. Made me curious, I calculated it for myself, then figured I could just make an easy to use equation for everyone else. So I broke out the rusty old algebra and came up with this. Someone can correct me if I'm wrong as it was a few lines worth of solving to make it simpler:

P = GX(1/Y - 1/Z)

where:
X = number of miles per month you drive
Y = mpg of current vehicle
Z = mpg of proposed vehicle
G = gas price in $ per gallon
P = monthly payment for new vehicle (don't forget insurance )

So you can plug in numbers wherever you want and figure it out for yourself. Also keep in mind this assumes either that your current vehicle is paid off, or that you will keep the vehicle and its current payments (effectively cancelling each other out). So to figure out my own gas price break even point (assuming $300/mo for a 35mpg honda civic):

G = P/X(1/Y - 1/Z)

G = 300 / 2100(1/17 - 1/35) = $4.722/gallon

or say at the current gas prices, what payment on a new 35mpg vehicle would break me even?

P = GX(1/Y - 1/Z)

P = 3.50 2100 (1/17 - 1/35) = $222/month

So I guess I'll be keepin the gas hog a while longer . I could prob go find a used civic or somethin, but I just don't dig buying a used vehicle from someone I don't know. Anyhow, lets see what everyone else's is!

[chook]

I got an 02 civic ex for 76000 last year. What that stupid formula doesn't account is the total cost of vehicle over its lifetime. Stupid formulas like this is how dogmeat says an H3 is cheaper than a prius.

[impala454]

Chuck, your vehicle costs money to maintain/repair no matter what you drive. It is a moot point.

[Dogmeat]

Or you could use the same spreadsheet I made 8 fucking years ago that recorded every fill up, oil change, accessory, figured in insurance, cost of depreciation, etc ... to figure out what your cost per mile to own your vehicle was.

http://www.spoh.com/~dogmeat/blank%20cost%20sheet.xls

example of my old trucks first 20k or so

http://www.spoh.com/~dogmeat/2000silverado.xls

[Mommy]

I found this a while back on the Orlando Sentinel site.

http://www.orlandosentinel.com/news/custom...0,3985576.flash

[impala454]

That spreadsheet is very admirable, but I'd seriously doubt the average joe keeps something so detailed. Not to mention have a similiar spreadsheet about the car they would be purchasing to compare with. Besides, what is the real difference in maintinence between any two given vehicles?

All this is is to help answer the simple question people keep asking: "Can I garage my current vehicle, purchase a better gas mileage vehicle, and have it pay for itself in gas savings?"

[Dogmeat]

That spreadsheet is very admirable, but I'd seriously doubt the average joe keeps something so detailed. Not to mention have a similiar spreadsheet about the car they would be purchasing to compare with. Besides, what is the real difference in maintinence between any two given vehicles?

All this is is to help answer the simple question people keep asking: "Can I garage my current vehicle, purchase a better gas mileage vehicle, and have it pay for itself in gas savings?"

Depends, what kind of vehicle, and how well does the owner maintain it? You start to see that once a vehicle gets more miles on it the better the owner has maintained it over the course of it's life, the less it costs them to own as it gains miles ... somone who never changed the oil, never kept it clean, never did anything to maintain it, the vehicle will develop more problems over the years.

Somone who drove the crap out of their vehicle, obviously, will have more costs associated with maintenence than somone who is a conservative driver.

Or you could own a Ford ....

[impala454]

Yeah true, some people really don't take care of their vehicles. There's this chick I work with that has a 2005 Altima that has been in and out of the shop like three times in the past six months. She's one of those ditzy types that's just completely clueless about changing oil/filters/belts/hoses/etc and keeps the thing filthy. It looks like it's been washed once every six months and has probably two hampers full of dirty clothes all strewn about in it. She's one of those types that goes straight to the club after work 3 days a week.

[chook]

Yeah true, some people really don't take care of their vehicles. There's this chick I work with that has a 2005 Altima that has been in and out of the shop like three times in the past six months. She's one of those ditzy types that's just completely clueless about changing oil/filters/belts/hoses/etc and keeps the thing filthy. It looks like it's been washed once every six months and has probably two hampers full of dirty clothes all strewn about in it. She's one of those types that goes straight to the club after work 3 days a week.

You could always not wash a car and take care of the mechanical parts. Gararging your vehicle and buying a new one probably won't pay for itself. If you sold your old one and got a more efficient vehicle (probably smaller than you like) you would save bukos cash, and could update your machine more!

[impala454]

You could always not wash a car and take care of the mechanical parts.

This is true for sure. I know with my old car I didn't really care about washing it all the time, especially in Lubbock.

Gararging your vehicle and buying a new one probably won't pay for itself. If you sold your old one and got a more efficient vehicle (probably smaller than you like) you would save bukos cash, and could update your machine more!

Yeah but the sad part is it's not all that far fetched. I personally would only buy new, but there's a guy at work here who kept his truck, bought a used civic for $7,000 and now drives it for his commuter vehicle. I would consider something like that but I just enjoy drivin the truck too much