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Hybrids and Those New EPA Fuel Economy Estimates
1/23/07

For those of you who aren't on our HybridCenter Driving Change Network, I wanted to put this here as well as our clean vehicles analyst Don MacKenzie and I had a chat about the EPA fuel economy estimates that I thought would interest HybridBlog readers as well.  Here 'tis:

Well, the change is now official—as expected, the Environmental Protection Agency's (EPA) new estimate for the Prius' city Miles Per Gallon is going to drop beginning in model year 2008. Unfortunately, some people are taking this opportunity to do an "I told you so" dance about hybrid technology, implying that perhaps hybrids really aren't such a good environmental choice.

I asked Don MacKenzie, our Clean Vehicles Engineer who has done a tremendous amount of work and analysis on this subject, to weigh in on the debate and provide a bit of clarity before the hybrid technology nay-sayers get too smug. Here’s what he had to say:

Here’s how I remember it: Consumers complained that they were not getting 60 MPG in their new priuses. Toyota said that driving habits and conditions would influence MPG, and that many consumers could expect to get less than the rated fuel economy. They also pointed out that this was true not only for their hybrids, but for their other vehicles as well.

I did some analysis of the numbers during the EPA's rule development and if people are concerned about saving money, it is interesting to note that your savings from buying a hybrid may, in many cases, work out about the same using the new numbers.

Think about an average vehicle that gets 25 MPG. It would cost you, say, $1,200 per year in gas to fill up your tank. If the new fuel economy estimate on that vehicle is 10 percent lower, then your new fuel cost estimate is $1,333 for the same amount of gas.

Now look at a hybrid that was supposed to get 55 MPG (the actual combined rating on the Prius under the old system). You would have expected the fuel bill to be $545. Now if it actually gets 44 MPG, you would expect the fuel bill to be $682.

Under the old rules, you expected an annual fuel savings of $655 for the Prius vs. the average car. Under the new rules, your expected savings is $651—basically the same.

It's good to get accurate information so you know what you're getting—which is why we consider the EPA’s new calculation procedures to be a good interim step on the road to more reliable MPG testing. And with good use of hybrid technology, you'll still be getting the most efficient vehicles on the market today. So the sky is not falling, and the emperor still has a pretty slick set of duds.

Thanks Don. Hope all of you find this helpful as well. Oh, and I don’t know about any of you other Prius owners out there, but I find I’m getting about 45 MPG city, 50 MPG highway, so the new estimates seem to be about right with my own personal experience.

Posted by: ScottN 1/23/07

Original post and comments can be found on Hybridblog.org.