Just to straighten a few things out:
- Running 1 quart of oil more in a stock system will not prevent a spun bearing. That statement is too generalized and in some cases that call for 3.5-4 quarts, running an extra quart could be the last thing you do to that engine.
- Adding more oil to an "older" engine is not the correct way to deal with loose tolerances. Moving up in oil viscosity numbers helps float moving parts within bearings that have bigger displacement area between the moving part and the bearing, but adding more of the same viscosity oil does not correct the problem. If you are losing more oil than normally consumed between oil changes, you need to correct the consumption problem. Be it leaks, bad ring seals, bad crankcase ventilation system or whatever the problem is, the oil loss will not correct itself by adding more oil.
- Running 10W30 Oil is not a good idea in ANY 7M-GE or 7M-GTE engine. 10W40 is the lowest recommended viscosity and is for constantly colder weather (below freezing). 15W40 is the base line viscosity recommended for naturally aspirated and turbocharged 7M engines.
- Running higher oil pressures will not damage your head gasket. The oil passages that run through your head gasket that feed the cylinder head and camshafts oil have absolutely no way of destroying themselves from a higher oil pressure. Blown head gaskets are usually caused by a combination of high cylinder combustion pressure and high cylinder temperatures that the head gasket simply cannot withstand.
- A crank scraper and or a windage tray is an excellent idea to prevent windage from oil contact with the crankshaft when the vehicle is in motion.
The truth is that raised oil level, even in small amounts does add to crankshaft windage. Adding a quart of additional oil, no matter the level, to an otherwise full system is still adding a quart of fluid to the amount of oil that is inside the oil pan. This means that you run the risk of having additional fluid from the added quart making contact with the crankshaft. A quart of fluid carries its own mass, no matter it's location or level in the oil pan.
