2010 Toyota Prius

2010 Toyota Prius

If you've been comparing the new 2010 Toyota Prius to the smaller, less expensive 2010 Honda Insight, Toyota would like to have a little chat with you.

They think that you think you'll save money buying the cheaper Insight. So, licking the corporate pencil and pulling out the compact calculator, they've roughed out some numbers to persuade you that the bigger Prius is all but a wash in pricing against the Insight.

The secret is that the Toyota saves in gasoline cost almost enough to make up for its higher purchase price.  And they've shared their calcuations on their corporate website, in a posting called "Hybrid Cost Analysis."

It compares a 2010 Toyota Prius equipped with level II trim ($22,000 plus delivery) to a 2010 Honda Insight. The Honda's not a basic LX but the pricier EX ($21,300 plus delivery). Toyota says the two models are comparable because they're "equipped the way most consumers want."

Toyota's table of costs says the Prius costs you $435 a month on a standard loan over 5 years, while the Insight runs $420. But gas costs, using EPA combined ratings (50 miles per gallon for the Prius, 41 mpg for the Insight), let the Prius save $172 less a year.

The result is that your $14 monthly gasoline savings all but covers the $15 higher monthly loan cost for the Prius.

"So for a buck more each month," the company concludes, "you get a roomier vehicle that is a full hybrid with better mileage ratings, enhanced performance, vehicle stability control, driver’s knee airbag, beltless engine, rear disc brakes….well, you get the drift."

There's also a head-to-head between the cheapest Prius with equipment level I (which will sticker at $21,000 but hasn't yet been released) and the 2010 Honda Insight LX, with a base price of $19,800. None of these prices, by the way, include delivery charges.

For the base models, the Prius costs $12 a month more, or less than $150 a year.

We're delighted that Toyota spelled out the assumptions behind its calculations, and compared apples to apples. But we do have one concern: We think Toyota is using overly high annual mileage figures, which raise gasoline cost higher than it might otherwise go.

The model assumes each car travels 15,000 miles a year (with gasoline at $2.62 per gallon). But that figure is more than 5,000 miles higher than the actual figure from last September that we found in a Brookings Institute report, which was 9,560 miles per year.

Many factors affect the per-capita vehicle-miles-traveled figure, as transportation geeks call it. One is that the newest cars tend to put on the highest annual mileage, with the number falling steadily as they age. That makes sense; older cars are often the second or third vehicle in a family.

We reran the numbers using the Brookings figure of 9,560 miles a year, and the Prius came off a little worse--though not much. The differential between a Prius II and an Insight EX rose from $1 to $6 a month, and the Prius I-vs-Insight LX penalty went from $12 to $17 a month.

Neither of these costs is enough to break the bank for most new-car buyers, and the 2010 Toyota Prius undeniably offers equipment that the 2010 Honda Insight doesn't.

Perhaps most importantly, the midsize Prius is at least a full car size larger inside than the subcompact Insight. On the other hand, the Honda's handling is preferred by some, and it doesn't have quite the polarizing image of the Prius. Not yet, anyway.

Every buyer needs to judge the numbers for herself, looking at annual mileage, projections of gasoline costs over the life of the car and, perhaps most importantly, which car they prefer to drive. Especially if they're driving that 15,000 miles each year.

2010 Honda Insight

2010 Honda Insight

[Toyota; 1994 Department of Energy data]