Hi,
Below we have two 5w30 oils, the first oil is a C3 ACEA spec and the 2nd is A3/B3. When you look at the hths for them the C3 is 3.7 and the A3/B3 is 3.5. The C3 has 0.7% sulphated ash and the A3/B3 1.24% ash. Both have similar viscosity at 100degrees so my assumption is that the additive...