I've been running conventional Castrol 20W-50 in my 380sl all summer because it significantly reduced the smoke I was getting while accelerating on exit ramps after highway driving, probably due to worn rings or valve stem seals.

But now that the temperatures are starting to go down, I wanted to have a lower oil viscosity at start up, and still have the higher viscosity when the car was hot. So, after seeing a number of good reviews, I was thinking about trying Castrol 5W-50 Synthetic, assuming that it doesn't start or exacerbate the leaks that some people have experienced in their older engines.

I was therefore wondering if anyone has used this oil and, if so, how it performed.

Thanks in advance for any info anyone can give me on this.