Overfilling by 0.5 qt - ‘17 Miata

[SHOZ]

I had a '72 351C Ranchero with the bad vacuum modulator valve on the trans. It sucked up a couple of gallons of ATF into the crankcase before I realized what was happening. It was filled to the valve covers!

 

[gfh77665]

I'm not so sure about that, the manufacturer puts those values on the dipstick for a reason. Granted, they may have left margin for error, but I wouldn't test that. Maybe they were counting for expansion when hot so left some space. Without actually disassembling & measuring oil height, crankshaft location, etc. we're just shooting in the dark. As important the issue of aeration is, I'd stick to the full mark, nothing more. A safer way to put that extra oil to use would be to find an oversize oil filter as mentioned above

Vehicles are designed to drive up and down grades for extended periods. A half qt. in a pan might raise the level a 1/4" or so, maybe less. If driving up (or down) a long grade is engineered into the tilt of a pans oil level, a half qt. is nothing. My dad habitually ran a full qt. low in his cars all his life. I and many others fill up to the next full qt., and have all my life. That even meant 0.7 at times.

Zero problems, ever.

 

[Fitter30]

Quart is 57.75 cu in
10x10x1= 100 cu in
Little over 1/2" in height

 

[ChrisD46]

Get the oil hot and rev up the engine in neutral. Then shut off and immediately look for bubbles in the oil on the dipstick. If you see any then it may be from windage.

One of Hyundais tricks for their grenading engines is a new dipstick that has a half quart more in it at full.

The Hyundai dipstick revision is to safeguard knuckleheads from letting oil level get too low … in the case of the Theta 2.4L engine the newer dipstick shows it can handle 0.5 qrts. extra in the sump.

 

[KrisZ]

It would be safer to underfill by 0.5qt than overfill if the level is still between min and max lines on the dipstick.

 

[SHOZ]

The Hyundai dipstick revision is to safeguard knuckleheads from letting oil level get too low … in the case of the Theta 2.4L engine the newer dipstick shows it can handle 0.5 qrts. extra in the sump.

You are assuming the knuckleheads even use the dipstick.

 

[SHOZ]

Whose to say the manufactures are keeping the oil level at a minimum to prevent the economy loss for the misting? Wouldn't be the first time they sacrificed in the name of MPG.

 

[cptbarkey]

there is another where they fabricated running an engine at crazy angles, i was really surprised things still ran normally until about 50 degrees.