First of all, thanks to Yannis who got me the link for Chevron's MSDS info. According to that Chevron 10/30 (dino) has a cSt of 10.8 @ 100 Celsius.... This is not really a very thick oil, is it? But I know that this is the most respected dino-oil on this site. How does it protect so well with that thickness? --Can i use this oil in hot summer? Compare: Pennz.HM 10/30: 12.2 cSt @ 100 C Mobil Drive clean plus(10/30): 11.4 cSt @ 100 Care these oils better than the Chevron 10/30 dino? --can I perhaps mix in 1Qt of Chev.10-40 or Delo 15w-40 with 4 qt. of 10/30 to make it thicker?any danger in doing that? Any opinions from Chevron lovers/others? please?