(MONEY Magazine) – SO YOU'RE FEELING THE PAIN AT THE PUMP, and you're thinking about getting a smaller car. It's just that they're so...small. How could you feel safe, when SUVs still roam the highways? Easy, says David Friedman, research director of the vehicle program at the Union of Concerned Scientists.

Q Small cars are fuel efficient, but people say that in a crash it's better to be the crusher than the crushee. Simple as that.

A There is nothing simple about the physics of a crash. Anyone who says,"Oh, well, it's simple physics: Heavier vehicles are safer' has no understanding of the physics of an accident. Cars hit each other at all kinds of different angles. Many SUVs are built on a stiff frame that doesn't absorb a crash well; cars are built to crumple in the front and rear while protecting the passenger compartment. If the vehicle doesn't absorb the crash, guess who has to?

Q But if a big SUV slams into my hatchback, I'm hamburger.

A A heavy, tall vehicle that drives stiffly, like many SUVs do, is more likely to cause fatalities in a collision. It's also more likely to roll over, which is why some SUVs have higher fatality rates than small cars. And because the roofs are weak and a lot of older SUVs don't have good air bags, you're more likely to be killed in a rollover in an SUV.

Q So what's the big-picture solution?

A Everyone could drive a heavy, stiff SUV, but that would only lead to a highway arms race and mutually assured destruction.

Q What about newer SUVs that are based on cars, not trucks?

A Initial data indicate that "crossover" SUVs appear to be safer. That's because their car-based chassis includes crash-absorbing space. Electronic stability control and more air bags also help. But these are still inefficient cars, and in spite of 9/11, Katrina and gas-price spikes, we're still waiting for safe, patriotic, high-economy cars and trucks from the automakers.

Q You drive a Civic. Ever lust after a muscle car?

A I used to ride a motorcycle. That was my muscle car.

Q But I bet you always wore a helmet, right?

A Always.

...Cheap thrills: In 2005, investors paid an average of 0.91% in mutual fund expenses, the lowest rate in 15 years, according to Morningstar...