Topsiders

[robi99]

I have been reading this forum and occasionally contributing for a long time. I know that most of you guys with newer Benzs' are using topsiders to suck the yucks out of the crankcase but I don't know why??
I have an '89 300E and the oilpan is very accessible so I just pull the plug.
My Dad just bought a '97 C230 and I'm wondering if he needs a topsider. He seems to think so and I agree but we haven't crawled under it yet so I don't know if it is necessary, easier, does it work better....what's the deal??
Also...while we are at it, the local MB dealer uses Castrol syntetic oil. Is it OK to switch brands?? Mobil 1 seems to be preferrd by most of you so I'm thinking my Dad might switch to Mobil instead of the Castrol that the car has used since new. It has about 45K miles on it.
Thanks for the help.....