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I read a stat that the average age of a car in the US is over 11 years old... that means that there are cars on the road significantly longer than 11 years (my Jeep ZJ is 18 years old, 172000 miles).
I think the biggest advancement in engine life was detergent motor oil. PVC systems are as old as detergent oil, but detergent oil was not really standard until the 50's.
BS speculation and/or opinions better suited to the Greasy Spoon?
The biggest advancement in engine life 70s-and-later is Japanese engines designed from "ground up" to meet pollution and mileage standards. Eventually, US manufacturers had to compete.
Modest improvements in domestic-use pre-70s engines' lives could be had, if you regularly changed an oil filter and an air filter.
Move this/my irrelevant post to the Greasy Spoon or delete it.
Thanks,
