Do the newer/lighter weight synthetic oils eg. 5w20 darken up quickly compared to the older “dino” oils (eg. 10w40)? I’m used to seeing a dark honey brown develop gradually over 3000 miles with the older v6/v8 viscosities, but these newer synthetics (in newer/smaller 4 cyl. engines) seem to almost get immediately black like diesel engine oil … why?
Just thought about it. Synthetic oils have special detergents to break up oil sludge and deposit build up in the engine. So, perhaps when oil gets dark fast it's a sign that the oil is doing it's job but the engine has the sludge in it? Need oil specialists here...
bingo
@jvin Yes it is not necessarily a bad sign that it is getting dark, it is keeping the gunk in suspension and will help get rid of it at oil change.
If it is getting really dark really fast, you may want to use some engine cleaner. The one Scotty Recommends from the guys in Arizona, ATS Carbon cleaner I think, may help if you got too much buildup.
That shouldn't be happening. are you changing the oil often enough?
I have noticed the same thing on both of my cars when I started using Castrol Edge fully synthetic motor oil, both for 5w20 and 0w20. This oil for some reason gets darker much faster than others I used before. I replace my oil every 4k-5k miles, however, after 1k I already notice oil getting darker, especially on 2016 Sonata GDI engine.