What is the difference between 0W-30 and 0W-40? My manual says use 30 but some people use 40.
06-12-2003, 07:09 AM
#4
30's not really thick enough IMO for anyone that drives their S4 hard...
...plus the original S4 owners manual called for a 5w40. This was before 0w's hit the market. Then people's turbos started failing possibly due to cold oil providing insufficient lubrication, and 0w30 was available so that crept into the owners manual. Then 0w40 finally became available, and seems to combine the best of both worlds. Plus, 0w40 satisfies the ACEA A2/A3 criteria specified by the owners manual (which nearly all w30's do not do), and in my experience runs cooler than 0w30 or 5w30 did, all while providing more viscocity protection.
Trending Topics
06-12-2003, 08:50 AM
#10
AG engineers changed recommendation to 0W-30 in latter models for superior lubrication flow rates.
<center><img src="http://pictureposter.audiworld.com/46293/castrolsyntec5w-50.jpg"></center><p>
The lower the viscosity delta, the faster the flowrate and enhanced turbo cooling. I use 0W-30 Mobil 1 every 5K miles in 70-90 degree F weather year round and saw a mean oil temp drop of 25 degrees when switching from this. ^^^
The lower the viscosity delta, the faster the flowrate and enhanced turbo cooling. I use 0W-30 Mobil 1 every 5K miles in 70-90 degree F weather year round and saw a mean oil temp drop of 25 degrees when switching from this. ^^^