How Much Oil Does My Car Need?

You can estimate how much oil your car needs by counting its cylinders.

  • A four-cylinder engine takes about 4-5 quarts of oil
  • A six-cylinder engine needs about 5-6 quarts of oil
  • An eight-cylinder engine takes about 5-8 quarts of oil

This is only an approximation, however.

To find out precisely how much motor oil your car needs, do one of the following:

Check the owner’s manual

Pull up the owner’s manual on your phone or dig the hard copy out of your glovebox and look up the information in the index. It’s usually listed under the section devoted to routine maintenance.

Check the AMSOIL Product Guide

You can skip the hassle and use our Product Guide to find out how much oil your car needs. Just input your vehicle information and, below the motor oil recommendations, you’ll find motor oil capacity (circled below in red).

AMSOIL products, AMSOIL product guide

What if the oil level is too low?

It could be due to a couple issues, including insufficient oil added during the last oil change or oil consumption. There are several reasons for oil consumption. But here are a couple of the more common.

Leaking seals or gaskets – your engine uses seals in various places to ensure oil stays inside the engine while contaminants stay out. A prime example is around the crankshaft where it protrudes from the engine and connects to the transmission. Gaskets seal the uneven metal surfaces between parts to ensure, in part, that oil stays inside the engine. The cylinder head gasket is a notable example.

If the seals and gaskets become worn, brittle or deformed over time, they can result in oil leaks. The engine oil level will drop, depending on the severity of the leak.

If your engine leaks oil, visit a mechanic and have it fixed.

Volatility – engine oil can evaporate when exposed to heat. The less stable the oil, the more readily it evaporates. As the engine is running, a thin film of oil coats the cylinder wall and piston skirt. Given its proximity to the fiery cauldron inside the combustion chamber, the oil in this area of the engine can easily volatilize, or evaporate. The byproducts can exit the tailpipe as emissions. But they can also form harmful carbon deposits inside the engine that reduce efficiency and eventually lead to engine failure.

Synthetic motor oil is more resistant to volatility than conventional oil, so use a good synthetic to reduce oil consumption due to volatility and help keep your engine clean.

What if the oil level is too high?

It’s likely due to operator error; someone simply added too much last time the oil was changed or topped-off.

Too much oil is a bad thing. The spinning crankshaft and churning engine parts whip air into the oil, which can cause foam. The tiny bubbles travel between moving parts, where they rupture. When they do, nothing is left to protect metal surfaces from wear. Foam also increases heat, which causes the oil to chemically breakdown sooner.

If the crankcase is overfull, drain the excess oil until reaching the correct level.

Increased oil level can also be due to fuel dilution. This is when fuel enters the crankcase and contaminates the oil. In severe cases, enough fuel can enter the crankcase to noticeably increase the oil level. This is bad. Very bad. Fuel dilution leads to sludge, varnish and engine wear.

The presence of coolant in the oil can also increase oil level. Again, this is bad. Anytime something that shouldn’t be in your motor oil is present, wear protection suffers. Coolant in the oil is likely due to a bad head gasket, which is a costly repair.

One last word of advice: check your oil at least monthly to ensure the proper level. Make sure the vehicle is parked on a level surface to get an accurate reading. Finding out the oil is too low or too high before something goes wrong can save you a ton of grief in the long run.

Updated. Originally published Dec. 3, 2018.

Comments

  1. Hi. I run INTERCEPTOR oil in my 2001 Ski-Doo MXZ 700. Toward the end of winter we were getting some good snow for a while, which put a hurting on the availability of sled oil. My go-to sled shop had 1 gallon of DOMINATOR left. I had asked him if I could mix the 2?? (INTERCEPTOR & DOMINATOR) and was told yes. I would hope I wasn’t fed some crap just to push out the oil. Regardless I had enough to last the season, so never blended them. AMSOIL recommends INTERCEPTOR when looking up my sled. I see INTERCEPTOR helps with the Rave Valves as DOMINATOR not so much. Am I good to blend? Possibly a little at a time? Kinda suck if not a good idea. Could take it back in the fall I guess if shouldn’t. And the response stating it from you and probably be a little ticked if he was steering me wrong and setting me up for failure. Thanks for your time.

    1. Hi Todd,

      Yes, you’re perfectly safe mixing INTERCEPTOR and DOMINATOR. One thing to note is the color, however. DOMINATOR is red and will affect the oil color as long as you’re mixing it with INTERCEPTOR, so don’t be alarmed.

      Thanks,

      John

  2. Changing oil doesn’t need to be a job that only mechanics need to do . You can always do that yourself.

  3. How do you figure out that the oil level is low? Can you check it on your own or you have to take the help of a professional?

    1. Hi Lary,

      Check the dipstick. It should contain markings that indicate whether the oil is within the acceptable range.

      Thanks,

      John

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