Oil Viscosity will it harm engine?


I put 5-20 mobil one synthetic in my murano, will it do any harm. manual calls for 10-30


Out of curiosity, why did you put 5-20 in when you knew it needed 10-30?

The problem with the thinner oil is that it may thin out too much in high heat conditions (eg. long highway drives in 35+C weather) and therefore won’t lubricate as well as the thicker, specified oil. You MIGHT be fine for a while, but change the oil sooner than the manual recommends. The Nissan engineers specified 10-30 for a reason.


Oil works in your main bearings by being pumped under pressure through the spaces between the crank surfaces and the bearing surfaces. It’s the pressurized oil film that keeps the surfaces apart. Too thin an oil could wash through too readily and not maintain the proper film under high stress conditions.

Use what your manual recommends. Or take the risk.


Thank you.
The genius at oil change place, put it in. I checked the manual when I got home.


I would take it back and tell them to change it for free. Then never even drive into the parking lot of a quick change place. We get a lot of reports of problems with all of them It is the nature of the business.


Joseph’s response is excellent, except that if it were me I’d take it to a reputable independent shop and get it changed to the proper weight. These lube shops make a whole variety of errors for a whole variety of reasons, and I’d rather just write the $25 loss off to the cost of an education than go through the agrivation of arguing with them and possibly having still another problem.