Engine Oil

I have just looked in my new Lotus Workshop manual to find their reconmmendation for engine oil, so I turn to Section OG page 2. Now I may be a plonker but what does the chart with viscosity on one axis and temperature on the other mean I assume there should be some crosses in the boxes to show what viscosity against ambient temperature… mine is blank
Am I missing the point!!!


Have read of this… http://www.xpower-mg.com/Motor_Oil_FA_Questions.htm it should explain all you need to know