Hybrid Car – More Fun with Less Gas

vehicle car ROI payback evaluation formula for vehicle comparisons

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Posted by drydem on September 21, 2008, 5:52 pm
Here is a short term ROI payback evaluation estimation spreadsheet for
looking at whether buying a used conventional vehicle ( with and
without comprehensive insurance) without considering resell value. To
compare with keeping an existing vehicle set cost to purchase/lease
to zero. If the vehicle is leased then cost to purchase/lease is equal
to the total contract value of the lease.   Much of this forumula
requires some estimating, e.g. estimating the average cost of gas over
"number of years" it also assumes (a risk unto itself) that the
vehicle will be driven uniformly of those years. To make things simple
- any financing cost to purchasing the vehicle must be included into
the "cost to purchase." Since this formula is to compare  the cost of
ownership of vehicles it does not include annual vehicle
registrations, licensing fees, tolls, and other government taxes/
levies. The estimated maintenance cost and insurance cost is the iffy
part of the equation

cost to purchase/lease  = 0 if owned outright  free of any liens.
                                         if you have a 200/month 4 yr
lease than the
                                         the cost to purchase/lease
would be 9600

number of years = (that the vehicle will be operating, if leased then
the length of the lease)

average annual cost of maintenance = depends on the age and condition
of the vehicle: 100 for 1 to 4 years old vehicle , 400 for 5 to 16
years old vehicle, 800 for 17 years or older vehicle.

estimated maintance cost = average annual cost of maintenance * number
of years

average annual insurance cost =  no comprehensive /
collision = you can  get
                                                  quotes via the

estimated insurance cost = average annual insurance cost * number of

average annual mileage

average miles per gallon (of fuel)

average fuel cost per gallon (over the N years) =
                          for my own estimates I add
                          about .50 to 1.00 per gallon for each
succeeding year...

estimate annual gallons used = average annual mileage/ average miles
per gallon

estimated annual fuel cost = estimated annual gallons used/ average
fuel cost per gallon.

estimated fuel cost = estimated annual fuel cost * number of years

Cost to operate =
  cost to purchase/lease  +
  estimated maintance cost +
  estimated insurance cost +
  estimated fuel cost

Using this model - a used 2000 Tercel/Corolla/Civic (without
insurance) would be significantly  cheaper to operate atleast for a
given eight
year period than a used 2007 Prius (with comprehensive insurance) if
price rise only $ per year (and one doesn't have any major accidents
or repairs to consider). That is to say this formula model suggests
that  a fully depreciated car is cheaper to operate than a not yet
depreciated vehicle - a hybrid's current level of increased energy
is not great enough to override this advantage. After putting all this
in a spreadsheet - I estimated that in  6 years.... If I drove much
more ( estimated 20,000miles/year instead what I actually am doing
currently which less than  9000 miles/year)  the cost
of operating a  2005 Prius and a 2000 Tercel would be about the same
in 6 years and if the average cost of gas over that period ws $/

total cost for next six yrs
    vehicle                       total cost       cost to purchase
   1990 honda accord        $5,800.00                    0 <-- currently
owned :-)
** 2000 toyota tercel        $2,300.00        $,500.00
   2000 honda crv        $9,900.00        $,500.00
   2000 toyota rav4         $5,536.36        $,500.00
   2008 hondat fit         $5,885.71       $5,000.00
** 2005 Toyota Prius      $3,800.00       $8,000.00
   2007 Toyota Prius       $0,800.00       $5,000.00
   2008 Toyota Prius       $1,800.00       $6,000.00

The vehicle selection choices were based on
the makes and models that have been on my mind
of late - probably due more to media hype than
any thing else - I feel uneasy at the above selection.
The CRV and RAV4 are functionally more useful than
the Tercel. The 2009 Tercel 5-door lift back looks alot
like the 2009 Honda Fit. Maybe I should been more
judicial about what I was comparing - since these
vehicles are very different functionally - To be fair one
should compare apples to apples - which the above
chart doesnot do that. My bad. I should have included
a used Saturn Vue Hybrid or the Escape Hybrid in
my comparisons too...(9_9) oh well...


Posted by Vaughn Simon on September 21, 2008, 7:52 pm

Maintenance is still a huge unknown with hybrids.  The Prius certainly has a
excellent reputation; but all else being equal, more complexity must mean more
maintenance cost and/or reduced vehicle lifespan.  Also, we don't really have a
good handle on the maintenance cost of replacement batteries, since most are
still covered by warranty.

I haven't spent much time with this one yet, but typical evaluation formulas
ignore a proper accounting for cost of capital.

Finally, vehicle purchasing decisions are rarely made in a totally dispassionate
manner.  Some of us (perhaps this writer) are likely to buy a hybrid simply
because that is our desire.



Posted by Trygve Lillefosse on September 23, 2008, 9:18 pm
 On Sun, 21 Sep 2008 19:52:22 GMT, "Vaughn Simon"

They are more complex I guess, but there have been wery few errors on
the Prius. Less than most, possibly all newer cars. It is a bit
baffeling, but I guess they have over-engineered it.

The batteries costs a bit short of $000, and you get a litle refund
for your old pack.

Still - even as Priuses have been used as Taxis, driving 5 times or
more as much as the average car, problems should arrise if there are
any. I belive there are some in Canada. I do not know how old theese
are on an average. But I expect that they will do more than 50K miles
a year, probarbly more like 60-70K and over.

There have been very few battery packs that have malfunctioned
worldwide. Although they are bound to fail at some time as all parts
of the car. It seems like they should last the lifetime of the car in
most cases.


Absolutely true. Never forget the feelings you get when you try a

The cooles thing about Prius is realy not that it's a hybrid, uses
less gas or the "gizmos" and touch-screen stuff.
The coolest thing is that it's completely quiet at low speeds, or when
it comes to a halt, and the relaxing feeling this gives you in a cue
or when picking someone up.

SEE YA !!!
Trygve Lillefosse
AKA - Malawi, The Fisher King

Posted by Vaughn Simon on September 23, 2008, 10:45 pm

   Based on years of experience and thousands of packs that I have been
responsible for on my job, I doubt that very much.  It seems that Toyota has
stretched the lifetime of the battery pack by using only a fraction of its
capacity, but still, a batttery is a battery and they don't last forever.

  On the other side of the coin, I expect that the price of a battery pack will
come down to a fraction of the present price once a real aftermarket demand
exists for them and market forces take hold.


Posted by Trygve Lillefosse on September 25, 2008, 11:19 pm
 On Tue, 23 Sep 2008 22:45:22 GMT, "Vaughn Simon"

Everything has it's end. But it seems like theese battery packs will
stay alive at least as long as an automatic transmission. And since
the price of changing both are more or less the same, I'd say that
there are no real ecconomic difference.

Possibly. Or they may go up as raw materials are in higher demand.
Then again - at some point there will be more packs returned for
recyceling. If that process is not too expensive, it may keep prices

SEE YA !!!
Trygve Lillefosse
AKA - Malawi, The Fisher King

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