when to add oil?
 

at what electronic oil level do you add oil to the box? is it ok to be one bar from the top or do you keep it always topped off???

I think its good to have it topped off. You can monitor it to see if you are burning oil and at what rate. If you are having to top off frequently it may be a sign of something to check out.
I've been meaning to figure out what theoretically each bar represets. I guess divide the number of bars by the volume of oil.

Actually, I would say that the bars don't represent a division of the total oil, but rather a division of the difference between "full" and "ok, but not full". In most cars, there is a 1 quart margin there, so maybe each bar represents .2 quarts?

Anyway, I would also say that adding oil because you are 1 bar low is a bad idea. In my car, the oil level indicator shows anywhere from full to 2 bars low, depending on temperature of the engine, whether the car's been running a lot, etc. If you notice a trend of decreasing oil, or if your level suddenly drops to zero, then yes, I would start worrying.

I use the dipstick. I trust German electronics about as far as I can heave the Boxster on a good day.

Yes, I agree. I should have clarified in my post that even if the sensor shows 2 bars low, the dipstick shows full, further proving that the bars are nothing to go by.

Toolpants commented that each bar represents about a cup of oil, and he ONLY uses his digital one as the dipstick isn't as accurate. It seems we have a difference of opinion.

I could believe that each bar represents a cup -- given that the range would then represent 1 quart (as I stated was standard).

I'm not sure if I believe that the guage is more accurate than the dipstick, although I would agree that it's easier to use. I would say that a combination of watching the guage, as well as checking your oil manually sporadically would be the best way to go about it.

I wouldn't put more oil in unless half the electronic bars are gone. The car holds 9 quarts of oil so anything around 8.5-9 quarts isn't going to hurt anything and is probably ideal. I'd also confirm with the dipstick as well because overfilling your engine can be much worse than underfill.

My '05 manual says each bar is approx. 0.4 liter, and when adding oil put in no more than 0.5 liter at a time before checking the guage again. And with no dipstick, I've got no other choice. :(

The 05's have no dipstick??? Wow.... Hope that sensor is accurate.

Mike

Scary isn't it! I am thinking of designing a retro dip stick and selling it on EBAY!!!!

:p

I'd buy it... :eek:

Nice to see some old school guys who still believe in the direct method!

:cheers: