Did the previous owner(s) have any mechanical sympathy?
Was it thrashed too much or before it had warmed up properly or only driven
to the shops by some old giffer and never given the chance to warm up?
Was it serviced properly with quality oil and parts?
An engine can last 20 mins or 120k + miles depending on the driver.
I bought a new one in 91 and got anywhere from 40-45 mpg. I changed oil
religiously and switched to Mobil 1 at 90K. Traded it in at 248K because
everything was falling apart around the car but the motor still purred
like a kitten. Leaked a little oil but burned none. Great car but as I
say, I bought it new.