Dipstick questions!

2 questions regarding dipstick on Gen 3 Prius:

1. What is the physical distance (inches or cm) between the top and bottom marks?

2. Is the oil level linear (meaning is the top 50% equal to the same amount of oil as the bottom 50%)?

 

Thanks. If you saw my fingers right now, you would understand why I didn't measure it.

Why do you think it's 1.5 liters and not quarts? Asking half seriously, and half-jokingly, since they are darn close. But did you have something official that says 1.5 liters?

BTW, Toyota dealership SWEARS it's 1qt, and that it is a standard across all vehicles. 100% sure they are wrong.

Not sure about the dipstick levels being linear. Recently got 28% fewer miles from bottom half of dipstick as compared to top half. But more data is needed to really know if the dipstick is linear or not. Very interested in everyone's experiences.

 

We do really like and trust the Toyota service advisor we work with. We actually drive an extra 45-60 minutes, past 2 other Toyota dealerships, just to see him. But we have no knowledge as to the competence level of the mechanic adding the oil (they recently had a non-certified mechanic perform a recall, which then had to be recertified by a properly trained mechanic), or the calibration of any oil dispensers being used (or whether or not they use a bottle - doubtful). Given that 0.2qt is the difference between a pass and a fail, everything must be done precisely.

We were never given the opportunity to check the dipstick after they filled it at the beginning of the test, nor verify only 1qt was added at the end of the test. We trusted them regarding the dipstick level they added the oil at the end of the test. It doesn't seem like they have an incentive to pass a vehicle needlessly, as it's less of an opportunity for repairs for them. But given that their results do not match ours, we must question the validity of the test.

What's curious is that they showed us the dipstick at the end of the test before they added oil, and it was only 1/4" from the bottom mark. If they added only 1 quart of oil, it shouldn't have reached the top dot, as they indicated. Actually, thinking about it now, when they showed up the oil at 1/4" from the bottom mark, the oil was hot. So as it cooled down while it was there for a couple hours, the level should have gone down. On the other hand, letting it sit for a while allowed engine oil to drip down into the pan from the motor.

Which do you think is greater, the amount of oil that drips down into the pan as the engine cools, or the volume of oil that is reduced as the oil cools?

 

Exactly. Which means as the engine cooled, it dripped more than 0.25 liters into the pan, or they added more than 1 quart, or they read the dipstick wrong after they added 1 quart. How much does it drip back down after cools?