the oil in my girlfriends prelude goes really dark and thin only around 2k miles...in my integra i drive it to 3k and it dont even look half as bad as her car...what would cause this?

 

dirty air filter,bad rings, unregular oil changes, ...

 

poor quality spark plugs / poor ignition system or too much fuel can cause fuel to leak past the rings into the oil pan causing thin diluted looking oil and or darker than normal oil.

but mmuller is right about the rings and filter

 

bad rings, cheap oil, poor state of tune

 

the car is stock, everything factory, yea im thinking bad rings...it makes the oil look almost dark red, maron color, then black

 

Maroon?? never heard of that.. Check your pcv system out, #1 on my list. the pcv system pulls the blow by out of the crankcase, if it isn't working your oil can look like **** in 1k

 

This is part of the reason I got rid of the drain-back on the endyne breather kit. Now I just need to change my oil again and see if it stays cleaner, longer.