Good lord Rick's Free Auto Repair Advice is worth what you paid for it. Compression brakes (of which Jacobs is one brand) actually do increase top end wear on a diesel quite a bit. What Rick is prattling on about might have been an issue in the 60s when engines would be well worn by 100,000 miles and PCV was not a thing. These days you're sucking crankcase gasses right into the combustion chamber constantly thanks to what's known as positive crankcase ventilation. Typically when you see a puff of smoke after overrun that's an indication of bad valve guides more than anything else (also not a common occurrence these days).
Oil in your catalytic converter isn't good, but that's why you have one or more spark plugs per cylinder — to burn it. There's the issue of heavy metals in the oil (e.g. zinc – generally in the form of ZDDP) that can damage your cat, sure, but that's why the current API specs have reduced the amount of allowable zinc a revision or so ago (API SN or SM I believe). Zinc is a great anti-wear additive but in high enough concentration can damage your cat.
Stop and go traffic will wear your clutch out (assuming we're talking cars with dry plate clutches here and not a motorcycle or anything else with a wet clutch). Engine braking will not (assuming you're not riding the brakes or constantly shifting while trying to slow down). Hell, even if you are downshifting needlessly if you're rev matching you're not wearing the clutch all that much. I'll take this fictitious clutch wear over acute brake failure thank you very much. In fact I've yet to destroy a cat or clutch in San Francisco traffic.
Oil in your catalytic converter isn't good, but that's why you have one or more spark plugs per cylinder — to burn it. There's the issue of heavy metals in the oil (e.g. zinc – generally in the form of ZDDP) that can damage your cat, sure, but that's why the current API specs have reduced the amount of allowable zinc a revision or so ago (API SN or SM I believe). Zinc is a great anti-wear additive but in high enough concentration can damage your cat.
Stop and go traffic will wear your clutch out (assuming we're talking cars with dry plate clutches here and not a motorcycle or anything else with a wet clutch). Engine braking will not (assuming you're not riding the brakes or constantly shifting while trying to slow down). Hell, even if you are downshifting needlessly if you're rev matching you're not wearing the clutch all that much. I'll take this fictitious clutch wear over acute brake failure thank you very much. In fact I've yet to destroy a cat or clutch in San Francisco traffic.