So I was checking the oil on my 03 G Caravan the other day and was surprised how dark it has already become.(3K) I was surprised because I ran my last OCI to 11K (PP 5w30)and although the oil was dark when it was changed it wasn't super black. Last oil was analyzed by Blackstone and they said it was "OK" and could have gone further. (Analysis is posed in applicable form) That was the first "synthetic" oil in this engine and the first oil change since I've owned it. This oil is already darker at 3K than the last at 11K. Does the 5w20 darken sooner compared to 5w30? Operating conditions are the same. (98% highway) Or is maybe this 2nd OCI flushing out all the junk kind of like the Auto-Rx rinse phase. I'm considering changing it because I have another 2500 mile road trip soon. I was planning on changing it after the trip due to some repairs I'm planning to do. What do you guys think, change it or leave it? Engine is the durable 3.3L and has 140,000kms on it.