Fun with hybrids.

Jim Motavalli's article "The Hot Hybrids" (Consumer News, November/December 2005) is generally good, but I have a few comments. First, as EV World (www.evworld.com) recently reported, both Toyota and Ford have on several occasions tried to bury the common misconception that Ford licensed hybrid technology from Toyota. In fact, after developing their own hybrid system completely independent from Toyota's, Ford realized that some of its technology was so similar to Toyota's that the two companies would do well to exchange patents, strictly for legal purposes. No money exchanged hands.

Second, I've been driving a 2005 Prius since October 2004, and while I initially was averaging furl economy in the low 40s (miles per gallon), once I figured out some tricks (some of which were published on the Internet), I was able to get that figure into the low 50s. I expect that to come down somewhat during the winter, but I'm at an advantage over most by driving in Houston. One quick tip: try to keep your throttle pressure as steady as possible. On flat terrain, driving at a constant speed between 35 and 45 mph will guarantee fuel economy above 60 miles per gallon during those stretches. In all likelihood, at some point the car's computer will decide to switch the gas engine off completely and keep it off until the battery is 50 percent charged, or you have to accelerate rapidly.

Third, let's lay to rest another misconception: that hybrid drive systems don't give you any benefit in highway driving compared to conventional internal combustion (IC) engines. Bull-hockey! My wife and I drove from Houston to Indianapolis and back in October and averaged 52 mpg during the entire trip (as determined by both the trip computer and from filling station receipts). This was at speeds between 65 and 70 mph.

My wife's Ford Focus, a car of similar dimensions to the Prius, averages about 32 mpg on the highway. I think the argument--popular among many in the European auto industry who continue to see hybrids as inferior to their diesel technology--is that the added weight of the hybrid drivetrain degrades furl economy at highway speeds. That just isn't the case, at least for the Prius and the Civic Hybrid, which I've also driven. These two cars average low to mid-50s on the highway unless you drive like a complete maniac. Plus, while weight may play somewhat of a factor in fuel economy, aerodynamics play a greater role, and the Prius excels in this.

Finally, as Pat Bedard at Car and Driver was quoted as saying, sure you can get the Environmental Protection Agency (EPA) fuel economy numbers. Just drive the car the same way the EPA does! I must say, I've enjoyed my Prius so much, I'm ordering another for my wife.

Christopher L. Durnell Ph.D.

via e-mail

I just finished reading your article "The Hot Hybrids" and wondered if you could offer some additional information. Could you please comment on how running the car air conditioner affects fuel economy? Also, are there significant costs related to replacing the bank of batteries in a hybrid car every few years? Finally, I keep hearing that there is a waiting list for these vehicles. What is taking the Japanese auto industry so long to ramp up production?

Ray Stetkiewicz

via e-mail

Jim Motavalli Responds: In many hybrids, including the 2006 Honda Civic Hybrid that I recently drove for a week, running the air conditioner in "normal" mode disables the "Auto Idle Stop" feature. In other words, the engine won't shut off at stoplights, one of the great hybrid features. In general, use of the air conditioner will reduce your fuel economy by five to 20 percent, depending on what car you're driving.