For me, one of life’s great pleasures is to get into a brand new car and go fast enough to make the speedometer show a higher number than the odometer. When I’ve had access to a test track, the speedo reached a number that more than doubled the odo. I’ve done the “Speedo Tops Odo” at least a couple of dozens of times, but the thrill is still there.

Sometimes it’s easy. I recently picked up a brand-new rental car with 60 miles on the odometer. I couldn’t quite get 61 mph before I left the rental lot. Then I went out on the freeway and took the above photo with my cell phone. Yeah, it was dangerous and stupid. If I had crashed into someone, I would’ve become a tasty morsel for a plaintiff’s attorney. Also, I almost had the opportunity to meet a member of a still-unknown law-enforcement agency. When the odo was at 80, a black, totally unmarked Dodge Charger with push bars on the front pulled up behind me. I slowed and he went on. I blame the editor for all of this. She requires pictures accompany words.

The best Speedo Tops Odo happened during a top-speed test for an auto magazine. Chevrolet tracked down a brand-new Camaro Z28 for the occasion. When it arrived at the test facility, its odometer showed 153 miles. It takes almost exactly three full miles to reach true top speed, and I thought the Camaro would break 155. I had a chance!

As the Camaro reached its top speed of 157 mph, the odometer read 156 miles. It was one of the high points of my career.

You’re Roger Penske, one of the most successful racecar owners in history and owner of a third of Ilmor Engineering, Inc. Still, the doors in the above photo are as close as you’re going to get to the dynamometer testing area at Ilmor’s Plymouth, Michigan facility during operations. (Waivers can be granted by the president—Ilmor’s, not Obama. Regardless, we didn’t get one.) It’s easier to get a tour of U.S.S. Ronald Reagan than to photograph dyno testing of the Honda IndyCar series engines Ilmor builds and tests for partner Honda. When RP visits, all engines are covered.

Ilmor’s engineers have been the largely unsung wizards behind engines such as the Mercedes pushrod engine that dominated the ’94 Indy 500 and the Chevrolet Indy engine of the ‘90s. Honda engines built and tested by Ilmor have won the past five Indianapolis 500s, two of those in Penske’s car. (Just like every other team, Penske’s Indy engines are selected by a draw conducted by series officials.)

For the uninitiated, a dyno is a device that measures torque and horsepower by simulating the forces an engine faces pushing a car down the road (or a boat across the ocean). There are several types of dynos. For one, the engine turns an alternating current electric generator. Another pumps water. NASCAR great Bobby Allison built a redneck dyno where the engine turned an airplane propeller. Ilmor has dynos that can handle up to 2,000 horsepower and others that accept 16,000 revolutions per minute (rpm). More...

If you’ve ever argued about the advantages of horsepower versus torque for more than an hour, you might be a car guy. An ill-informed car guy, but a car guy nonetheless. When the informed discuss horsepower and torque, they know the two are intertwined.

Torque is a twisting force that requires no motion. Imagine trying to turn a locked doorknob. Torque in engines is measured on a machine called a dynamometer.

Horsepower is calculated. The formula for horsepower, designed as a marketing ploy by James Watt around the time of the American Revolution to promote his new steam engine, is engine revolutions per minute (rpm) multiplied by the torque at that engine speed, divided by 5,252. In every engine, horsepower equals torque at 5,252 rpm—or someone’s math is off.

Here’s a surprise for the ill-informed: Neither torque nor horsepower is “better.” More...