I have about 220K on my 4000 (1.7 liter) and the engine is still running well. I had to have several seals done around 160K to 180K though. I bought the 5000Q about three years ago when I thought that the 4000 would die. The 4000 hasn't died; it's my daily driver and it costs practically nothing to keep running (esp compared to the 5000). michael