Is the top mark really "too full" on the oil dipstick?

no. anywhere between the dots is fine. of course, on a refill, you'd like it near the top, so there's room for consumption. some do like it a bit lower than the top, but i'm not sure why.

the interesting thing is, most complaints are about overfilling.

 

Keep the oil at the top mark. Tiny bit overfilled is not an issue. Oil does not expand when it's hot.
That would be a really bad thing if it did.

With a new filter the engine takes exactly 3.6 quarts. Not much oil it needs every drop.
You have to let the car sit a long time for accurate measurement, lots of oil in the cylinder head area to service the VVT oil driven system. Takes a long time to drain back,

Check the oil first thing in the morning before starting the car. Watch it for a while. The dealer overfills the crap
Out of a Prius which makes me think your car eats oil. It would be amazing it didn't eat oil given it's miles and is dealer serviced,

Prove me wrong. Check it first thing in the morning for a while.

 

I've never seen noticeable change in the oil level, hot vs cold. And at least starting out at the top mark is good practice, you have a greater volume of oil at work, and more leeway if the engine's consuming some.

It's standard practice at an oil change, to put in the spec quantity, which should in turn set the oil level at the top mark.

 

Your car is fine. Just drive it.

Glad you are checking your dipstick. It amazes me how some people never check their oil level. Then they come on here and complain about engine problems, after they found out the oil was below the bottom dot for a couple years.

 

I've put up to a qt beyond the full mark w no air impregnation and I'm running the third gen at full rpms for extended periods.

 

What is air impregnation?

Btw you can get it overfilled by a quart every time just have the dealer change your oil.

 

This is true but only partly.
When you put "cold" oil into a hot engine, it only takes a couple of minutes of running for it to get "hot".

IF......they do 1000 oil changes a month, by leaving out 1/2 quart of oil, they "save" 500 quarts and up their margin.

You were right to complain. Take it to the owner.

 

Top of the line is not too full. Between the lines is not under full. Anywhere between the marks is good. Typically I try to leave mine slightly below the top mark 3/4 to 4/5 of the way to the top mark.

If you're thinking the dealer skimped, make them top it off, but your car is fine as is.

 

Take it to what owner? It's a car dealership. They never checked the oil till 2 weeks later. It was ridiculous to even call about it, all you will get is some service advisor douche who could care less about somebody's oil change 2 weeks ago done but god knows who. She's lucky they filled it with oil.

 

OK, I guess you can't read anything between the lines.

NEXT oil change, check it before you leave.
IF it is a half quart low again, demand to speak to the actual owner of the dealership to complain........as at that point it would be fairly obvious that they are doing it on purpose.

Better ??

Or.....just take whatever crap they give you and whimper away. Your choice.

 

What did I miss between the lines?

You put cold oil in a hot engine it gets hot. Got it.
And dealers are instructing there oil change monkeys to short everyone on there oil changes by one quart so they can save money. Its a conspiracy. These are people cant figure out how much it takes to begin with. Got it.
Next oil change check it and if low demand to talk to the owner of the dealership. Got it.

 

Your hyperbole certainly isn't helping the discussion.

 

Nothing new there.

 

YES.
Once you start using a "high mileage" oil you need to stick with it......and in a slightly heavier weight than recommended for "new" service.

If that inch drop represents a loss of about a quart of oil in 500 miles, you NEED to get a shop to look at it.
Something might be drastically wrong......like a leak somewhere.

 

Oil in the Prius is to be checked with the engine at normal operating temperature (hot) while parked on level ground. It should be between the two marks. IF: at the lower mark, you can add 1/2 qt or so, if at upper mark, it is FULL. The two marks represent the "operating range" of the oil in the engine - think of it like the fuel gauge. Anything in between is good, AT either end is where we need to pay real attention.

 

That's not accurate. In point of fact, "High Mileage" oil is nothing more than a marketing gimmick to get folks to pay more for oil. Do the oil companies change the formula? Yes, but not anything that CAN change oil consumption, help seals or anything else.

Also, ANY oil that someone tells you cannot be mixed with other oil, or you must stick with once you start.... either find a new information source, or run from that shop/garage. All engine oil is OK to use with all other oil, period.

High speed driving could be a significant contributor toe this. Make sure they check what's called the PCV system too!

 

I've read "high mileage" oils have additives to swell rubber seals, and that if you subsequently go back to a regular oil (synth or not) the seals will shrink, with accelerated oil consumption.

Once you start with high mileage oil, best to stick with it?