Dipstick - Ever Notice This?

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2018 AWD GT Premium Red/Black
See post #49, the manual does explicitly say that the engine should be at normal operating temperature, so yes, warm oil. And oil does expand when it warms up so a cold oil reading will be different.

But if owners think they know better than the factory, they can do whatever the heck they want. Afterall, I’m not making their car payments…
The quoted directions in post #49 make no assertion whatsoever as to what temperature the oil should be when you put the dipstick in to take the reading.

It gives a sequence of instructions. At one step they say to bring the temperature up to operating temperature. During this step the dipstick is seated in the tube.

The next step, prior to removing the dipstick is "wait at least 5 minutes". I've explained why I believe that step is important.

Waiting 12 hours during this step is completely consistent with these directions.

There is no explicit instruction to measure the oil while the oil is still warm. I don't believe there is an implicit expectation either.

The time to NOT measure your oil while following these instructions are:
1) if its been fewer than 5 minutes since the engine was run to operating temperature
2) if the engine didn't reach operating temperature the last time it was run
3) if the engine hasn't been run with this oil

I expect cases 2) and 3) would be fine if enough time had elapsed.

The instructions are such that they give easy steps to get a relatively steady state oil level reading starting from uncertain conditions.

There are plenty of other ways to determine how much oil is in the car. The instructions need to be clear and deterministic and able to be followed by typical owner. They don't need to be exhaustive.

I don't envy the folks who have to write instructions for such things. Wow.
 
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HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
The ever popular "how to read a dipstick" topic which I'm resurrecting with a new observation.

I just did an overnight cold check and then a hot check after waiting about 10 minutes, both in my flat garage. The readings were very close, the hot check a tad higher this time, about half way between low and high, same as my cold checks since an oil change 3,000 miles back which makes me happy.

Here's the thing. Prior to all that I had backed the car out of the garage to top off the tires and then went to check the oil after 5 minutes or so. The engine had only been running maybe 10 seconds after sitting overnight. The dipstick read at the low mark. The driveway has a very slight incline downward toward the street, a couple degrees at most. To see if that made a difference I pulled the car into the garage, again with the engine having been run maybe an additional 10 seconds. The dipstick then read just a tad higher than the low mark.

The logical conclusion about those 10 second run times is the oil didn't get hot enough to drain in 5 minutes, kind of a "duh" moment. If the engine is hot, a 5 minute wait time suffices. "Or more" on an overnight wait time gives me a result with small enough variation to call it close enough. I still prefer checking cold after sitting overnight, just because it is easier to get a clean read on the stick.
 
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