The detailed results: The '02 Prius with 208,000 miles on it got 40.4 mpg overall, compared to 40.6 mpg for the '01 Prius when it was brand new. Highway fuel economy for the old, used Prius was 48.3 mpg, compared to 48.6 mpg on the new Prius back in '01. And in the city, the numbers were 32.1 mpg compared to 30.5 mpg, respectively
When it comes to acceleration power, the difference was also negligible – the old used model went from 0 to 30 mph in 4.4 seconds, compared to 4.3 seconds for the new model 10 years ago. And, when the 0-to-60 time was measured, the numbers were 13.1 seconds and 12.7 seconds, respectively.
Even so for a 10 year old car its doing very well compared to lets say a 10 year old corolla or a 10 year old BMW, performance numbers would fall, by a huge amount, and many many problems occur as well.
Full article below, its worth reading! esp proving those skeptic wrongs!
Ten-Year Old Toyota Hybrid Priuses Defy Early Critics