i did a long searching from a couple different forums about pennzoil ultra oil.
I haven't found a recent UOA or reviews on this oil. Could someone make comments on this?
i am basically looking for engine oil that'll handle high temp.
Castrol 0w30 and mobil 1 0w40 both showed dropped in oil pressure significantly at high oil temp. Castrol 10w40 showed better oil pressure but this eats too much oil.

 

go to www.bobistheoilguy.com and my opinion is never use ZERO grade...what you are getting is Zero W Zero with improvers...problem is after engine runs for say 600 miles or so the improvers burn off leaving you with little protection...I use 10W30 in my engine. and last why is there even a zero grade? the mfg were having trouble making CAFE regs so they are running this very light oil in their new cars WITH very low tension in the OIL scraper ring...read a few posts here regarding that. All of this is to pick up maybe a .1 in gas mileage, OK for them to pass without gas hog charge but no so good for us @6600rpm

 

Amsoil.

But there's not need to run a 0 weight in our cars. As the viscosity ranges increase ie.. 0-40 vs 10-40, the amount of additives needed to make the oil perform like a 0 and 40 weights go up.

 

http://www.bobistheoilguy.com/forums...Board=3&page=1

 

i did make a thread on that website regarding oil.
A bunch of vq owners use castrol 0w30 and mobil 0w40. That's why i tried them out. Thanks for good info.
I thought the Weight is just about the range of temperature the oil can handle(?), and 0w seemed OK to use in CA.

My choice of engine oil is restricted within what autozone sells i change my oil often and their reward car pays off.

 

let me make myself clear, EX) 10w40 has more additives than 0w40. isn't it better to have less additives?

 

It's harder to make an oil perform at wide viscosities than it is to make it perform at closer viscsoities. IMHO.

 

i wouldn't make the assumption that the 0w oils are WORSE at performing than non-0w's...

I personally burn less oil using 0w-30 GC than say... 5w-30 M1 EP..
and with winter temps hitting below zero time to time here, i definitely wouldn't use 10w weight..
I think all oil is different 0w-30 GC and 0w-40 get singled out because they are approved by BMW LL-01/04 (i forget which).. they are pretty thick up top at 100*c, but i think the VQ engines do like the thickness.

but i am no expert..