Dear Car Talk:

Can you tell me where I could find a comparison between the slant of the windshield and the mileage achieved by the car? For 21 years, we drove a ’91 Mercury Tracer with a moderately slanted windshield. The car averaged over 30 mpg all but two of the years we owned it. We drove it from coast to coast, Canada to Mexico; we even towed our small boat on a trailer and carried our canoes on the roof. Then we decided that 22 years was old enough for a car, so we traded it in for a 2010 Hyundai Elantra. I hate almost everything about it, starting with the slanting windshield that is full of reflections of the dashboard and inside of the car. The very slanted window posts obstruct my vision. Looking at other cars, I see that the general trend is more and more slant to the windshields. Is there some justification for this, within the speeds one usually drives in town and occasionally intercity? The Hyundai doesn’t seem to do as well with mileage. You would think in over 20 years, there would be some improvement. — Jean

There has been improvement, Jean. The 2010 Hyundai’s mileage is nearly 20 percent better than the ’91 Mercury Tracer’s. While EPA ratings are better for comparison purposes than for predicting real-world mileage, the ’91 Tracer was rated at around 25 mpg in combined highway and city driving. And the 2010 Elantra is rated at 29 mpg combined.

In addition to better mileage, the Hyundai also carries a lot more safety equipment, with a bunch of air bags, anti-lock brakes and a better-protected passenger compartment. And unfortunately, that improved mileage, despite the added weight, is partly due to those darned slanted windshields you hate.

You’re right that windshields are more severely angled now than they used to be. That’s because they make cars far more aerodynamic. The less wind-resistant a car is, the higher its mileage.

Driving with a windshield that’s straight up and down is like trying to walk into a strong wind with a big pizza box taped to your chest. That big, flat box is going to make it harder for you to push your way through the wind.

But you’re absolutely right that there also are drawbacks to steeply angled windshields. One is that they really do tend to pick up reflections. If you leave anything on your dashboard, like a parking stub, you’ll see it reflected right in front of your eyes on the windshield.

And some dashboards themselves, especially if they’re anything other than flat black, reflect in the windshield. It can be very distracting. And, as you mention, the longer A pillars (the front roof supports on the sides of the windshield) can block your visibility, especially in urban environments where pedestrians, are crossing streets as you make right turns.