[javadog]

The gauge may be fine; you just may be misinterpreting it. It only measures the level of the oil in the tank. When the engine is running, obviously not all of the oil is in the tank. Don't worry so much about absolute numbers.

First, check your oil level using the dipstick. This is the only thing that really matters. The engine must be running and at normal operating temperature. If you get the oil level correct in the tank, then take a look at where the guage indicates the oil level to be, with the engine running, at idle, on flat ground and at full operating temperature. Don't worry about what the absolute value is. The gauge just gives you a rough idea of where the oil level is and isn't very useful in actual operation.

Another thing to consider is the oil capacity of a 911 wasn't exactly the same over the years. There were different oil tanks and other things that affect how much oil is replaced when changing the oil. The only number that is important to you is how much yours holds. Also, not everybody keeps their oil level at the same place on the dipstick, so when they tell you how much to put in, it may not be what your car/engine combination needs.

If all else fails, read the owner's manual for your car. If you don't have one, track one down and buy it. There's usually nothing wrong with running the car like it tells you in the manual. Sorry if this sounds a bit obvious but you'd be surprised at how many people never read the manual to learn about their cars.

Hope this was helpful,
JR