Dear all!I am used to check my oil and hydraulic quantities in percent, but now most of my airlines use oil quantity use quarts. So what do I look for, I mean what is a healthy quantity.Many thanks!

I didn't think that Quarts were used for anything other then milk is the USA? The oil quantity readout displays in liters.

I didn't think that Quarts were used for anything other then milk is the USA? The oil quantity readout displays in liters.

In US based aviation US quarts are commonly used units for oil quantity. The NGX oil quantity options are percent or quarts (US quarts in this case). There is no option for liters though as a rule of thumb 1 liter is about 2 US quarts. I just did a comparison between the two options with oil tanks full:Eng 1: 88% = 18 QtsEng 2: 99% = 20 QtsSo it seems 20 quarts is pretty much maximum.Kevin Hall

OK thank you!I also saw this used in the KLM version, so I guess intl. carriers also use this value.I should be looking for 1o to 2o quarts then for a normal operation.Thank you!

Yeah, SAS has quarts too

Searching FCOM2 for "Oil Qty" finds liters (7.11.15 etc.) but I could find no reference to quarts.

1 quart is almost equal to a liter.

Searching FCOM2 for "Oil Qty" finds liters (7.11.15 etc.) but I could find no reference to quarts.

Well maybe PMDG made a mistake, because the options available according to the NGX Introduction manual (0.00.68) and the CDU are percent or quarts. The FCOM also says there is no option for oil quantity units in the side by side display (percent only), but the NGX switches units according to the option selected.

1 quart is almost equal to a liter.

My mistake, you're right. My calculator converts liters to pints. I know you must divide that by 2 to get quarts but when posting just read the number off the display. Should have known anyway because a liter of beer is just under two pints.Since the units aren't displayed you could read the numbers as either liters or quarts and not be far out.Kevin Hall

Hi Kevin, a quart is 1/4 of an American gallon, not an English (or imperial) gallon. A US pint is only just over 4/5 of a UK pint. Ask for a quart of beer in the states and you will feel seriously short changed if you were expecting a couple of pints. Just ask the barman that threw me out :)I think it is more likely that the error is in the Introduction manual and that it should have said "Choose between percent, and liters"

For technicians is better to use quart.One oil can is 1 quart. (Yes I know, is like a liter, but they are not exactly the same)

Then why use quarts and not liters where you have a perfect standardized system with "SI base units"? Well done Boeing...On another matter, in the MD11 when starting the engines declining oil amount in the reservoir ,about 5 for the MD11. Anyone who knows how much it is the 737?

Hi Kevin, a quart is 1/4 of an American gallon, not an English (or imperial) gallon. A US pint is only just over 4/5 of a UK pint. Ask for a quart of beer in the states and you will feel seriously short changed if you were expecting a couple of pints. Just ask the barman that threw me out :)I think it is more likely that the error is in the Introduction manual and that it should have said "Choose between percent, and liters"

I was referring to US units the whole time to avoid confusion, anyway people rarely use the quart as a unit in the UK. The US pint being smaller is definitely an advantage because that means less American beer to drink. I agree the mistake must be in the PMDG manual and the error is repeated in the CDU page which refers to quarts too.Kevin Hall

The manuals are straight from Boeing - if there's a mistake, it's theirs.

There is no error.The manual is right, speaking about liters or quarts is almost the same.Why a company uses quarts? because it is a simple way to decide how many oil cans you must use to refill the system. Is a direct way istead of the %.As you can see in the picture, the can is exactly a quart, or 0,946 liters.Some data:Oil tank capacity21 US quarts (20.2 liters), on the right engine the quantity is a bit more.The indication is for 18 liters, a quantity more than 18 quarts must be considered as 18 liters.A LO message shows when the oil quantity is less than 4 liters for 35 seconds. The oil quantity shows in reverse video when the low quantity exceedance is active.

OK I will be looking for 18 Quarts next time around!Thank u!