Yep...I've used Castrol M exclusively for the last 45 years or so and it mixes perfectly but needs a good shake at first. After that it never settles out. I get it in the 5 litre container from my local Caltex depot (where I get methanol in bulk too) and from memory it was about $12/litre. I've even ordered in the Castrol M through a local auto parts shop who stocked the normal Castrol oils for cars.