Seat of the pants, GC vs Pentosin

[Ken E.]

Dumped the GC out of my BMW 318iS with M42 engine this weekend after 8000 miles. Replaced it with Pentosin 5w-40 and found immediate noticable difference. The start-up clatter is virtually gone and the engine is much quieter. I think I'll stick to the 40 wts. from now on for these older Bimmers.

 

[RichD]

I too have a 318is (M42) and have been using GC (which I really like although I still need to determine where some oil is leaking). I recently purchased some Pentosin Pentosynth 5W40 just to compare. They are somewhat similar oils although I don't know what the base stock is of the Pentosin Pentosynth 5W40 other than it is a Group IV or V I believe. The 5W40 is a bit thicker than the 0W30 obviously but they have very similar amounts of calcium, zinc and phosphorous and the Pentosynth has a minor dose of moly.

Your difference between old and new could simply be that, comparing 8,000 miles old oil with new oil. Keep us apprised and I will do the same.

Regards,

Rich

 

[JAG]

Here's an MSDS for this great oil: http://www.worldpac.com/msds/WP_057.pdf
Obviously the 1-Decener Homopolymer component is PAO and I think in this case "Synthetic Oils" is some kind(s) of Group 5 for additive solubility.