Plug-in Hybrid vs. Tahoe Hybrid

Earth2Tech had a post on converting your Prius to a plug-in and christian g left the following comment:

Many people spend $35,000 for a car. I spent $25,000 for a Prius and am upgrading it with an environmental amenity for $10,000 and will be cutting my carbon emissions in half in the process. I couldn’t think of any better way to “invest” the money.

While the commenter's logic does have some appeal, it raises the interesting question of whether there is a better way to "invest" the $10,000 to help the environment.

Let me make the environmentally sacrilegious case that the money could be better used helping others upgrade from large SUVs to hybrid SUVs than converting a Prius to a plug-in.

According to Hymotion after the conversion, the plug-in Prius will get 100+ mpg (plus some electricity usage) for 30-40 miles.

Assuming that the normal Prius gets 40 mpg and the plug-in Prius gets 100 mpg, if you drive 12,500 miles a year, converting to a plug-in saves (312.5-125=) 187.5 gallons of gasoline a year.

According to this NY Times article:

Giving a four-wheel drive Tahoe a gas-electric hybrid engine raises fuel economy for city driving to 20 miles a gallon from 14.

But a couple in Longview, Tex., Michael and Cindy Pittmon, have found that their Yukon hybrid was worth the investment. “I’m getting 20.8 miles to the gallon compared to 13 on my old Yukon,” Mrs. Pittmon said. “It costs $75 to fill it up, and that’s lasting me two weeks instead of one.”

But to get the better mileage, consumers pay a high price: $53,000, at least $4,000 more than a conventional Tahoe.

Assuming that the hybrid Tahoe gets 20 mpg and the standard Tahoe 14 mpg (the numbers stated there are just city driving, but Mrs. Pittmon's numbers are for everything and her numbers show a greater advantage for the hybrid, so 14 to 20 sounds reasonable), if you drive 12,500 miles driven a year, the hybrid saves (893-625=) 268 gallons of gasoline a year.

$10,000 would allow you to upgrade 2.5 SUVs for a savings of 670 gallons of gasoline a year. That is over 3.5 times as much gasoline saved as upgrading a Prius to a plug-in. (Ok, you can't really buy .5 of an upgrade, but lets assume that had $20,000 and could choose to upgrade 2 Priuses or 5 Tahoes, and then the numbers work out.) You would save an additional 4.8 tons of CO2 emissions by helping others upgrade to SUV hybrids, then you would by converting your Prius to a plug-in.

But, you might argue that upgrading a large SUV to a hybrid makes economic sense without regards to the environment, so new SUV purchasers will opt for the hybrid version on their own. At $4 a gallon, the 268 gallons a year a hybrid doesn't use saves $1,072. On the $4,000 investment, this is a 26.8% rate of return, much better than just about any other investment out there. The additional costs of the hybrid pay for itself in 4 years and then all savings are pure profit. If you were to get a 5 year loan on the car, the additional payment for upgrading to a hybrid would be lower than the amount you save in gasoline. It is not even clear why anyone would purchase a non hyrid large SUV at this point.

So are all SUV purchasers switching to hybrids? Um, not so much.

G.M. has sold about 1,100 of its Chevrolet Tahoe and GMC Yukon hybrids since their introduction in January, according to company sales briefings. That pace is well behind its goal of 12,000 sales a year, and a fraction of the more than 100,000 hybrids sold so far in the United States this year.

Why aren't they?

Glenn Galvan of Reno, Nev., was hoping to replace his Honda pickup with one of the G.M. hybrids until he saw the prices. “I don’t mind paying the extra cost for environmental reasons, but it doesn’t have near enough fuel savings to justify it,” he said.

Well, no one ever accused large SUV drivers of being the sharpest tools in the shed.

While upgrading your Prius to a plug-in might make you feel better and give you more status with your environmentally conscious friends, if you want to reduce as much CO2 emissions and gasoline usage as you can, spending $10,000 would be better used to help help those that are purchasing a large SUV upgrade to a hybrid. Not that purchasing a large SUV is ever a good environmental decision, but as long as anyone is actually purchasing them they should be a hybrid and helping others to do so makes a bigger impact than converting your own fuel efficient car to a plugin.

And just to make it clear that I am in no way supporting the purchase of large SUVs, I will take one last unprovoked swipe at large SUV drivers:

She said that the big hybrid generates quite a bit of attention at stoplights and in shopping malls, particularly because of multiple “hybrid” badges and decals that G.M. put on the exterior.

“People are always saying, oh, they didn’t realize that hybrids came this big,” she said. “But I’m thinking about taking some of the badges off so it doesn’t stand out as much.”

Yes, you don't want them thinking that you might actually care about minimizing your gasoline usage or helping the environment, now would you?