1988 300SEL question

[Snibble]

I looked at the owner's manual and can't find the answer to my question. The "low oil" light indicator flashed today after a 30minute drive. How much oil is there between the spot beteen the two arrows on the dip stick and to when the indicator lights up that you're low on oil?

Also.. a year ago I got around 418miles on a full tank (20.5 gallons, not including reserve). This year I had a pretty bad milage showing... somewhere in the nieghborhood of 280 miles. Now, I just reached the MIDPOINT and am at 186 miles for a half tank.

418 miles on full tank: 90% highway 10% street
270 miles on full tank: 80% street 20% highway
186(half tank) est. 372 miles full tank: 75%highway 25% street

As a driver, I like to go about 70-75 on the highway avg. Obviously less when there is traffic and road hazards. With the above figures, am I in the "normal" range? I freaked out a little when I got 270 on my tank and wasn't sure if I had some sort of engine problem. I did a search in the archives and found a stat for a 300SE... but since its a shorter chassis and weighs less, I would imagine the milage would be different than that of an SEL.

What scares me right now is the oil consumption of my engine (m103) with 189,500 miles. I have to check my records as to the miles it had when I did the last oil change, but I am guessing around 1700 miles. I get my wheels rotated for free at Goodyear since I bought a set of new tires and warranty, and I get coupons for $18 oil changes ( I supply my own Mann oil filter). If it went from normal range to a range that triggered the light on my dash, how much oil am i losing?Doing a search, it seems that the m103 does tend to lose oil.

Comments are appreciated.
Sharif