The 2006 accord and the 2008 accord are both EXL Inlne 4 with automatic. where the 2000 is a SE with L4 and auto.

The emission test for the 2008 accord came back with a reading of 0 for CO% and 0 for HC ppm. Those readings are taken at 2500 rpm and at idel. so i guess the engine is fine.

I went to another dealer and looked the exhausts on other used 2008 accords. The exhaust on those cars are almost as dirty, guess its a normal thing for 2008 and newer accords.

So i asked another honda dealer about the compression test. He told me that according to honda manual the pressure for the compression test should be 134.8 psi, but he isnt sure if its the min, max, or average ideal pressure.

Another thing to consider is that Accords have gained weight over the years. Your 2008 EX is heavier than your 2006 EX which is heavier than your 2000 SE. More weight means more fuel, even if US EPA mileage figures show otherwise.