Oil color in different applications

[ThirdeYe]

I know it's been debated here time and time again, even lately, but I was curious about another aspect of it. The 2001 Daewoo Leganza I maintain always turns the oil darker in color in a short period of time when compared to other vehicles I maintain. Ever since we've bought it, it turns oil dark brown in less than 3,000 miles. I'm currently using Havoline Synthetic 5w30 in it, and it has about 2,500 miles on it put on in a time frame of about a month (they do a lot of highway driving). When I used the same oil in the 2003 Malibu I maintain, it didn't turn this dark even at 5,000 miles. I know it's not really an indication of how it's performing, but what would explain it getting darker in one application so soon compared to the other application? A look through the filler cap in the Daewoo provides a few of a nice clean valvetrain and I've always changed it between 3,000-4,000 miles since I started maintaining it a few years ago.

 

[bepperb]

Yeah, our HL has roughly the same engine as our Accord, but the oil is much darker and very quickly. It has an oil/coolant heat exchanger whereas the Honda does not. My assumption has always been that the oil temp is higher on it, but it also has a smaller sump. Nothing to "clean" in either.