Jackie Stewart, in his book Principles of Performance Driving, says that you should use the brakes to slow down. You should downshift *while* you are braking so that you are in the correct gear and ready to go immediately after releasing the brakes -- which you should do *gently*. Tony mentioned the reason: you can break your clutch or gearbox by over-zealous engine braking and the brakes are designed to slow the car down -- not the clutch/gearbox.

I used to rally race and do some SCCA autocross. I have had some (not enough!) training in performance motorcycle riding.

Gearing down while breaking is hard to do correctly. By "correctly" I mean that you change the engine speed to the correct speed for the next gear down while the clutch is "in". In a car, that means all three pedals need to do something -- brakes on, clutch in, accellerator to match revs -- all in the time you are gearing down. They call it "heel and toe" because you end up using your right foot for both brake and accellerator, but as it was taught to me you use the right side of the right foot for the accellerator, not really the heel.

It is slightly easier on a bike, but still difficult to do smoothly because you need to work the front brake and the throttle with the same hand.

On the other hand, this is all for performance driving, but I think the principles are applicable to any kind of driving.

Racers also spare the brakes and brake as little as possible. A race driver would not use the brakes to slow down 5 mph in traffic because he/she would anticipate the traffic and just let off the gas a bit. In that sense, I suppose, they are engine braking.

I think it was Maseratti who said that, "you can always tell a good driver in the city because they rarely use the brakes." That's not because they are going crazy with downshifting, but because they *anticipate* the traffic, lights, etc. and don't ever need to make sudden adjustments to the car.

On a bike, slowing by downshifting can be dangerous because of the sudden torque change to the rear wheel. Its like using only the rear brake. If you do it too aggressively, you can easily crash. Same goes for a car, but it is less sensitive. Not good to do in a curve, though...

On long hills, using engine compression is necessary so the brakes don't fade. Its especially important for heavy trucks. Modern cars have really good brakes, so fade is much less of an issue than it was 20 years ago. I remember the first time I experienced fade -- I pushed the pedal as hard as I could and there was nothing there! Definitely something to avoid in the mountains!

Jim