The 600SEL's oil is quite low and i'm going to top it up. The manual recomends (for the temperature pretty much throughout the whole year) 10W-40 and 5W-50. I'm thinking of 10W-40 but does anyone know which brand of oil I should use? I want long lasting protection as well!

 

Mobil 1

 

^^^
ditto

 

So you guys are reccomending synthetic oil. I dunno, the car has been using dino oil (i'm very sure) since it rolled out of the factory. I don't plan on changing it at the moment so do you think mixing the oils will be alright?

 

SInce you are topping it off, use the same type of oil that you have already. Your owners manual (sometimes the filler cap) will suggest which oil weight.

During your next oil change, use mobil 1.

 

Any quality name-brand synthetic or dino oil is fine. I wouldn't recommend grocery store oil. Use a weight appropriate for your climate, change your oil regularly, and you'll be fine. Synthetics will mix with dino oils fine.

I use Amsoil 10W-40. Amsoil because it's a quality synthetic that I can get delivered to my door, and 10W-40 which is fine year round for San Diego.

Brett