I have an 03 duramax I just bought in the fall. I have been running Shell Rotella conventional since I purchased it. What is a recommended span between changes? I have been told anything from 5,000 miles to 10,000 miles. I dont want to over due it or obviously under due it. Would love to hear everyone's opinion.
the milage intervals you see recommended on this site and others will vary for a few different reasons. First, people use there trucks for different things. Hauling your kids down the highway to a soccer game is a lot easier on the engine oil than idling in a swap for days on end. Your driving habits and use of the truck play a large role in deciding when to change your oil.
If your truck has emissions the oil is likely to pick up more soot and other undesirable contaminants than a deleted truck, so emissions intact would mean you want to change oil more regularly than a deleted truck with identical drivers and use.
Some people also do oil analysis to decide when to change the oil, typically though this is only done by people who run expensive oils like amsoil that cost a small country's GNP to change. Oil analysis is a good idea though to monitor engine wear, i am not convinced its a good idea to run oil until the analysis shows its bad though.
temperatures play a major role in oil breakdown and life, if your towing in the mountains in summer, that oil is going to get very hot and its service life will be diminished compared to someone driving out to the lake on the weekend. (again, driving habits and use play a huge role)
Filtration is another place where you will start to get different answers on oil life. Some people install bypass filters that take a small portion of the oil pumps flow and filter it at a very fine micron level to remove soot and other deposits from the oil before returning it to the pan. These systems can keep oil very clean for a long time, and this is where you start seeing really high change intervals with some people reporting being in the 30K range between changes.
Capacity is another variable as well, if you have anything extra that adds oil capacity, be it the bypass system, a aftermarket pan, aux filters, a larger filter or a dry sump with external storage then your interval may change, since the service life of the oil is based on the quantity in the pan from the factory, more oil means more dilution and less wear for the same number of miles on average.
Basically, you need to decide if you are hard on your truck, or if you baby it. If you are hard on your truck, change it at the 5-6K interval (or even sooner if you really beat on it) if your just using it as a grocery getter, it doesent idle a lot or get beat on at red ligths then go ahead with the higher change interval and just keep an eye on the oil level and make sure it doesent look or smell cooked.
I think anything in that range would be fine. Iím surprised it hasnít been asked yet.
it has. many.... many........ many times.