HIGHER RPMS DEFINITELY ARE LESS EFFICIENT

Dear Tom and Ray:

A friend and I are having a running debate that I was hoping you two would be able to settle. We each recently bought ourselves pre-owned vehicles, and we both are members of the dying breed of drivers who love to drive cars with manual transmissions. Both cars are in stellar shape, both have fewer than 30,000 miles and have their original clutches, both have spotless Carfax history reports, and both were given the thumbs-up by our mutual mechanic when he inspected them. The disagreement is about driving styles. My friend says that he gets better average fuel economy for his car when he drives at higher revs in a lower gear. I, on the other hand, believe that driving lower revs in a higher gear is more efficient. For example, he says that driving 60 mph in 4th gear at 3,000 rpm gets you better mileage than driving 60 mph in 5th gear at 2,500 rpm. What do you say? -- Marie

RAY: While he's reading this first paragraph, Marie, we'll stall for time so you can double your wager. Because he's got his headlight firmly implanted in his taillight socket. He's nuts.

TOM: Completely. The higher the engine revs, the more fuel it uses. It's like walking. On the same terrain, the faster your legs move, the more calories you burn. And the same is true for your engine.

RAY: That's why, in chasing better fuel economy, carmakers have continually added more gears. In the 1950s and '60s, most cars had three-speed transmissions. The Ford Focus we drove a few weeks ago had a six-speed automatic. And the BMW X3 we drove last week had an eight-speed!

TOM: Why? Because the higher the gear, the fewer times the engine has to turn for each rotation of the car wheels. And the slower the engine turns, the less fuel it uses.

RAY: If your friend is really thickheaded, Marie, and refuses to concede, suggest that the two of you take a bike ride.

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