Maybe this is a basic question but I’ll ask it anyway. Does anyone know with any certainty how much oil your engine is “down” or low based upon the marks on the dipstick? If the top mark says “FULL” and the bottom mark is just a mark . . . are most showing 1 quart down? Is this peculiar to the engine? I ask only because we have a lot of new posters who use oil but don’t know how much they are using based upon the dipstick. Rocketman

I don’t know with certainty, but the bottom mark on every car that I’ve seen is for adding one quart.

A better question might be how linear the dipstick is when it’s below that mark, which I suspect varies by car.

All of the cars I’ve ever had measured about one quart between the full mark and low mark on the dipstick.

Speaking only for my 2000 Blazer (4.3 V6), the difference between the top and bottom marks is about ~1 quart. After an oil change, the oil is at the 1/2 mark. I add about a 1/2 qt to bring it to the full line. By the time it’s due for an oil change (4-5k) the oil level is getting close to the bottom mark. Usually I try and keep the oil level between full and 1/2 on the dipstick since the Blazer started using a little oil at the 100k mark.

Ed B.