Due to extremely hot South Texas summers and 1.5T Honda Civic engine being hard on the oil (including fuel dilution) planning on putting in some 0w30 (0w20 is prescribed by manual). I've got some 0w20 left from my previous order and wonder if mixing two grades is safe in terms of oil physical properties and chemical compatibility. Do you guys practice mixing different grades? Engine takes 3.5qt so was thinking to mix 2.5qt of 0w30 and 1qt of 0w20.
Thanks
Thanks