im running 10w30 john deere break-in oil now. after 1000 km i will dump oil. i have 4L john deere breakin left. can i mix it with shell rotella 15w40 or shell rotella 10w30?

 

Do not mix any of the weights of oils. I have mixed brands before though. I use the Rotella 15w40 and I purchase it at Walleyworld. Dont know if thats the best

 

could i mix my 4L jug of 10w30 johndeere breakin oil with 8L of rotella T 10w30 for the next 1000 km?

 

Don't mess around with engine oil. What you'll have left over is only about $20 worth of oil; big deal. You're risking way too many $$$.

Always use a good quality brand of oil, in the proper viscosity. If you live in the frozen north, and don't do much towing, you could probably get away with 10W-30. But once it starts to get warm, or you start working the truck, it's time for the proper oil.

If you're going to drive 5,000 miles between now and spring, go ahead and use what you have. If not, it will end up costing you extra in time, effort, and a new filter.

 

I use the John Deere 15/40 CI4+ and love it!

 

If the API classifications are the same (correct for your engine) the oil viscosity is less of an issue, regarding mixing 10 W30 with 15 W40, unless: extreme hauling, mountain racing, or baja'n.