Sunday, May 1, 2005
Q Dear Tom and Ray:
I'm considering buying a hybrid car, but someone recently told me that because I do a lot of highway driving, I will not get nearly the mileage promised in the ads. The reason I was given is that on the highway, the gasoline portion of the engine is used rather than the electric portion. Is this true? -- Gayle
A RAY: Well, Gayle, no one ever gets the mileage promised in the ads. But it's true that the benefits of hybrids are tilted toward city driving.
TOM: Here's why: Hybrids combine a gasoline engine with a battery-powered electric motor. In Toyota's hybrid system (which is the most popular), the battery power is called on first. So if you're just driving gently in city traffic, you might use only the battery a lot of the time. And if you're stopped at a light, you're using nothing!
RAY: That's when a hybrid will save you a lot of gasoline.
TOM: At higher speeds -- above 15 mph or 20 mph -- or on harder acceleration, the gasoline engine kicks in. And, while the battery is still assisting the gasoline engine, you rely much more on the gasoline engine. So, at highway speeds, you still get good mileage, but the boost isn't quite as great as it is around town.
RAY: Incidentally, the reason nobody gets the Environmental Protection Agency-rated mileage in their car is that the tests are totally unrealistic. The tests are done with all of the accessories off, including the heat and air conditioning. In reality, most people have at least some accessories on all the time. Every accessory requires some power and lowers your mileage.
TOM: What makes the difference even greater on a hybrid is that turning on a major accessory, like the heat or AC, automatically turns on the gasoline engine. So, even at low speed around town or when you're stopped at a light, if your AC is on, your engine is running and you're using gasoline.
RAY: The Prius EPA test claims ratings of 60 mpg in the city and 51 on the highway. We have yet to meet anybody who gets even close to that. Most Prius owners we talk to get somewhere between 40 and 50 mpg -- which is still fantastic! You may be very happy even at the lower end of that scale, Gayle. But the mileage is not what the EPA leads you to believe.
TOM: It's time for the EPA tests to join the real world. Turn on the AC, let a few pounds of air out of some tires, throw a mother-in-law in the back, and then we'll see some real-world mileage estimates.
Dear Tom and Ray:
You lugheads -- and I mean that in a good way -- keep talking about the proper way to drive a manual transmission. Well, I have an automatic and know nothing about shifting from "Drive" to "1" or "2" and back. Those numbers aren't just for decoration, are they? Thanks for all the laughs. -- Anne
RAY: Automatic transmissions are pretty much "set it and forget it" these days; 99.9 percent of your forward driving can be done in "Drive." When the transmission needs to be in a lower gear, it'll shift itself into a lower gear.
TOM: There's only one really important exception, and that involves long, steep hills -- but only when you're going down them. On a steep mountain road, where you'd need to be on the brakes pretty much constantly for more than half a mile or so, you should shift the car into a lower gear. Shifting down in that situation uses the inertia of the engine to help keep the car from going too fast.
RAY: That prevents you from overheating your brakes, which leads to brake failure, which leads to a life-insurance claim.
TOM: Try the next-lowest gear below "Drive" first. And if you still need to ride the brakes to maintain an appropriate speed, drop down another gear, all the way down to "1" or "Low" if necessary.
RAY: Some people suggest that you downshift for extra power when going up hills, or when your transmission is shifting frequently between two gears. But none of that stuff is really necessary. During normal driving, if the transmission really needs to be in a lower gear, it'll figure this out itself.
Got a question about cars? Write to Click & Clack in care of The Post or e-mail them by visiting the Car Talk Web site athttp://www.cartalk.com/.
2005by Tom and Ray Magliozzi and Doug Berman