Mobil 1 Synthetic oil

I use Mobil 1 in both of my cars. Unfortunately, one car recommends 5W-30 and the other recommends 10W-30. I know you shouldn’t mix different viscosities, but you should be able to use either viscosity in either engine. Is this correct?

hey, i started using this stuff Sunday in my xr75 dirtbike (10w-30), anyways depending on climate wherever you live, recommendations of oil types are usually better to use, however, any viscosity will work and shouldnt probably not be too hard on your engine.

For the correct viscosity you need to consult your car’s Bible, the Owner’s Manual. That said, you likely can use either oil in either car without a problem. The difference between 5W30 and 10W30 in a synthetic oil is really very little.

Note: there is no reason not to mix different viscosities of modern oil. You would just end up with something like 7W30.