i remember seeing pics on the net ... about some honda owner running high speed on 5th gear and mistakenly downshifted to 2nd gear instead on 4th, which of course is effectively an engine brake to the extreme ... ayun, nawasak ang makina nya

i believe engine braking should not be a habit during normal driving ... it only wears out parts unnecessarily ... there are only few cases that it is useful, e.g., downhill ... but on downhill, i still reduce speed using brakes then downshift and slowly release clutch while rev matching, after which the car have already slowed down to safe speed and gravity takes over to keep the car moving while the engine provides the resistance to keep the car at fairly steady speed ... i take care not to exceed 3000 rpm to prevent stress on engine so i still briefly apply brakes whenever necessary on a long downhill stretch ... on a curve, i simply brake early so there is no need to use engine brake ... i don't drive fast in an unfamiliar road where a curve could appear unexpectedly, more so when the road is wet ...

but for people who love to race, it sure does pay to know how/when to use engine brakes ... there are situations that engine brake is the only way to perform a certain stunt ... i'm not a race driver but i think they use engine brake routinely while in a race.