Hi Shane.
That oil will be fine. Very black oil is normal. The oil is doing its job by holding soot in suspension. I may have opted for 5w/40 if i was towing or experiencing extreme heat like you guys do.
Only way to tell if oil is holding up is to have it analysed. When i was working, the company had an account with an oil supplier that offered this service. Only issue i ever had was a high soot level on one analysis.
One of the cheapest places to get the oil here in UK is the mercedes dealer, believe it or not. They sell a 20 litre container called a lube cube. Much cheaper than any of the well known brand oil.
|