I've read posts on here about people mixing Mobil 1 15w 50 with Mobil 1 Racing 0w 50, seemed like a reasonable thing to do. I asked Mobile 1 about this, and they said:
'Thank you for your inquiry. We do not recommend mixing due to viscosity break down. Especially the racing oil, which is not for street use.'
I am not quite sure how mixing oils can cause a 'viscosity break' down?
'Thank you for your inquiry. We do not recommend mixing due to viscosity break down. Especially the racing oil, which is not for street use.'
I am not quite sure how mixing oils can cause a 'viscosity break' down?