Oil should be checked with the engine fully warmed up on a level surface a few minutes after shutdown. Since most gas station pads are level, checking it after filling the fuel tank is a good time. I usually remove the dipstick before I start pumping, wipe it off and lay it on the cowl. This allows the oil in the dipstick tube to drain down and will give you a clearer reading when you insert it back in and pull it out.

Mercedes spec for my engine is 6.3 quarts, and I believe all the 103s are the same. Check your owners manual!

"Engines develop their own level" is gobbledygook. What happens is that without checking and adding as required the level will slowly drop due to consumption (which is normal) and leakage, if any. I suspect that with the passing of Frank King, the technical editing of The Star has suffered. (I quit MBCA years ago.)

There have been stories posted about lower oil consumption if the oil is run low, but I don't buy them. At most they are suspect anecdotal evidence. Overfilling may cause excess consumption, but filling up the the manufacturers "max" mark should not.

On my engine the oil light will come on intermittently when the level reaches about halfway down between the plastic indicators, which is a little less than a quart. I usually then add one-half quart, and if the light comes on again, I have a data point on oil consumption, but being as how I drive my car so little, it usually doesn't need any oil between its annual changes.

On refilling after draining I add 6.2-6.3 quarts, and this brings the level up to the full mark. During draining I jack up the right rear of the car to allow the last few ounces to drain out (the drain plug is at the left front of the pan), and the plug is usually open for about 20-30 minutes, while I perform other tasks.

I usually maintain the oil level on all my cars at or near the full level. For track events I sometimes overfill them. The best way to spin a bearing is to jocky a car around corners with a low oil level!

Duke