Calculate savings on gas driving Prius

Given: MPM (miles per month), $PG (dollars per gallon), MPG1 (previous miles per gallon), MPG2 (new miles per gallon)

Find: SAV (savings in $ per month)

SAV = MPM x $PG x (1 / MPG1 - 1 / MPG2)

If you have an HP17BII calculator, you can enter the equation as written in "SOLVE" mode and the 5 quantities will label 5 top-row keys. Then you can input any 4 quantities (by pressing the numbers and then the labeled key for each) and pressing the 5th labeled key will display the calculated value.

Sample Calculation: MPM = 1400, $PG = 3, MPG1 = 15, MPG2 = 55

SAV = 203.64

So this says the SUV I drive 30 miles to work and back 5 days a week, and average 50 miles on weekends costs me $203.64 a month more than it would if I drove a Prius. In a year the Prius would save me $2443.64 on my gas bill. If the trade-in on my SUV is $15,000, I would break even in 4.09 years. If the price of gas goes up, I would break even sooner - in fact if over the next few years the price of gas averages $4/gal, the break-even time would be 3.07 years. This does not account for any variation in trade-in value at different car dealerships so I assume Toyota allows the same as any other make, dropping it out of the calculation.

If you think rewarding Toyota the $10,000 difference for their development of this hybrid system is better than paying it to Shell Oil and adding to the world's pollution for 4 years, it should be an easy choice.

Reply to
Chuck Olson
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This is the most straightforward and logical calculation I've seen for calculating the payback period for a hybrid.

I've heard reports of Prius fuel economy as low as 45 MPG, which plugged into my HP 17B II (with a new formula) comes out to a monthly savings of $186.67, or a 4-1/2 year payback if the difference is $10,000. If you keep the car for 10 years, and assuming the batteries last for 10 years, then you're ahead of the game by almost $10,000.

Reply to
Ray O

I think you need two calculations before you are finished looking at this. In the first calculation, you figure out how much you save on the gas bills by getting rid of the SUV, then compare the Prius to whatever you used in the calculations against the SUV.

There is no question the SUV costs a small but increasing fortune to drive, but there are replacement models that are cheaper than the Prius, and give the ROI (Return on Investment) much sooner. The que4stion you need to answer is, is the cost-up for the Prius worth it?

You can dump the truck and get a Camry and save enough in a month to make the payments, the question is, will there be enough extra savings with the Prius vs. the Camry to cover the added cost of buying it? Get it?

PS The answer may very well be yes, the Prius is a good value. But, most analysts seem to think that Prius owners will not keep the cars long enough to have the fuel savings pay the added cost of purchasing them.

Reply to
J Strickland

My take is get a cheap car (maybe two years old) with good mileage, easy to maintain, like a Corolla or something like it. Keep it for a long time and in the later years it will become a clunker but cost you nil. You will be dollars ahead. BTW, how much is insurance on the Prius?

Reply to
Dbu''

The obvious omission is the "time cost of money".

You lay out the $10K in 2005 dollars, but the savings is in future dollars. E.g., if you could invest the $10K at 5%, your Prius is costing you another $500 a year.

Reply to
kgold

I still refuse to pay for that damned car LOL Seriously, though, we do very little driving on the whole, so I don't think it would be a bargain for us.

Natalie

Reply to
Wickeddoll®

The same math applies when comparing an Echo or XA or any 2 vehicles. The payback is a lot quicker with a conventional fuel-efficient car.

Reply to
Ray O

Wickeddoll® wrote: :: :: I still refuse to pay for that damned car LOL Seriously, though, we :: do very little driving on the whole, so I don't think it would be a :: bargain for us. :: :: Natalie

Yes, but it will get cheaper. At least I seriously hope so, because I want one and I'm not paying *that* for it either!

Reply to
Bioboffin

The three to five thousand dollar premium one pays to buy a hybrid will buy ALL of ones fuel for three or four years. To say nothing of three to five thousand dollar premium one must pay to replace the battery pack, at some point down the road, if they keep the vehicle long enough in an effort to recover the original premium they pay to purchase the vehicle.

Seems to me one can not benefit financially buying a hybrid. The best one can do is help save the planet, if that is their desire

Reply to
me

I doubt it will get cheaper - - there was a "mid-year" increase of $300 in the MSRP already. I suspect the only thing that causes a price reduction is lagging sales due to obsolescence, which is where the rest of the industry is at right now.

Reply to
Chuck Olson

The planet don't need any saving. Otherwise I agree totally in your assessment of the hybrid cars.

Reply to
Dbu''

:: The three to five thousand dollar premium one pays to buy a hybrid :: will buy ALL of ones fuel for three or four years. To say nothing :: of three to five thousand dollar premium one must pay to replace the :: battery pack, at some point down the road, if they keep the :: vehicle long enough in an effort to recover the original premium :: they pay to purchase the vehicle. :: :: Seems to me one can not benefit financially buying a hybrid. The :: best one can do is help save the planet, if that is their desire :: I think that may have been what I said. However, unlike some of the other posters here, I do think the planet is in need of a little help.

John.

Reply to
Bioboffin

I care too, but just can't make *that* leap. I recycle every possible consumable, but paying that outrageous price for that tiny car chafes my sense of duty to the planet. It's preposterous to have to pay Toyota's outrageous price for a car that they know is merely an idealistic toy for the tree-hugging set.

Natalie

Reply to
Wickeddoll®

Why do you call the price "outrageous"? Hybrids are more expensive to make than regular cars.

I disagree with your assessment that the Prius is merely "an idealistic toy for the tree-hugging set". Certainly, it doesn't make sense for most people today, but they have to start somewhere. It fills a niche in the market, and gets volume manufacturing started.

Reply to
dizzy

But on these cars, the gas engine is running a LOT, especially if you have the AC on.

Then, on top of that, you have batteries to dispose of at the car's End Of Life, so where's the Eco savings? And they aree made of the same materials as other Toys; some MAY be more easily recycled, but on a whole, no.

Basically, in it's present state, this car is a gadget for people who love gadgets, and for those who like to make a statement, whether they really are or not.

Don't get me wrong; I LOVE the car; I like the older ones better on a whole, but the newer ones are sleek, roomy and run very well. But you aren't really saving ANYTHING by buying one!

And when I had the chance to drive one for a while, I did no better that my '95 Tercel, that has the same engine as the gas unit in the Prius:

42MPG for the Tercel, 41 MPG for the Prius.
Reply to
HachiRoku

Since you're an idiot, that doesn't count for much.

Reply to
dizzy

Why must you assume that everyone that is not on the left is an idiot?

Why must you be a dizziot?

Charles of Kankakee

Reply to
n5hsr

I don't. There's actually a few righties here who are not "idiots", IMO.

If "dizziot" means "exceptionally intelligent person", I guess it's just my curse. 8)

Reply to
dizzy

Like right-wingers, you mean?

It sure is easy to make claims. Much harder to provide evidence of those claims.

Reply to
dizzy

My bicycle uses no gas, plus I get some exercise. Save the world and get in shape! This is "outdoor" exercise, as opposed to Natalie's "indoor" exercise :-) The good news is I get exercise and my kids get off the sofa. The bad news is we ride to the ice cream store . . . .

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Reply to
ma_twain

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