Here are our best-selling passenger car engine oil and diesel motor oil viscosities for the past year. These statistics are based on our sales only, so these numbers are not indicative of sales in the overall motor oil market.

Passenger Car/Light-Truck Motor Oil Sales Rankings

One of the first things we looked at is how much market share 5W-30 still holds. Automakers have been steadily moving to 5W-20 and 0W-20 motor oil for several years. If one adds the market share of 0W-20 and 5W-20, they eclipse 5W-30 by 12.59%.

The 0W-16 viscosity was introduced in 2018, but sales literally didn’t move the needle. It was suggested for only a couple of Honda and Toyota models in 2018. It will be interesting to see if 0W-16 starts to make strides in 2019.

Chart Passenger Car Viscosity 2018

Diesel Engine Oil Sales Rankings

The story in the diesel engine oil space over the past few years is 5W-40 replacing 15W-40 as king of the hill. The 5W-40 grade is now a common (and very viable) all-season choice in many diesel engines. Again, these stats are based on our sales and not the overall diesel engine oil market.

Chart Diesel Oil Sales By Viscosity 2018