UOTE=thescreensaver18545]^ how long do you run it for?[/QUOTE]

I ran my jeep for 22,000 miles. I'll prolly run this oil for about 15k.

I been using Mobil 1 5w-30 full synthetic. i wanna switch over to German castrol 0w-30 but isn't that a lighter weight oil than 5w-30. i tried 0w-30 Mobil 1 once and it burned threw that oil like crazy barley had a drop on my dip stick. and i change every 3500. maybe it was a fluke i may have done a lot of racing during that change who knows.

In my experience, even with my old oil consuming motor, it burned less oil with GC 0w-30 than M1. Can't explain it, but it's true.

switched back to castrol after trying mobil1 since it was on sale and alot of people praised it. has drastically less to no clunking at startup or idle

GC 0W30 is a thick 30wt oil, on the 30wt scale it is almost a 40wt.

In comparison Castrol Syntec 5W30 is a very thin 30wt its almost a 20wt.

Based on what...a UOA?

i use mobil one 0w40 and love it, i read a long discussion on one of the zforums about it and people were sending oil samples in and from what i got out of it 0w40 did the best for the vq

^ M1 0W40 is a fine oil indeed

and its easy to find and not badly priced i pay no more than 8 a quart at walmart so its easy to get which is what i like as well

^ Just wait for m1 to be on sale at AAP or Autozone can get 5 quarts and a filter for 30 ish bucks :)

It's the same. 0w is thinner than 5w in the cold, but it's the same when the motor is warmed up. Supposedly, you just want to avoid using a 0w oil if you live in colder climate since the thinner oil is more likely to freeze up. Althoug the guy who wrote up the thread on my350z says the thinner oil would be better for the cold.

Mobile1 has been known to burn away ever since they changed their formula a few years ago.

^ thinner Oil is generally better for cooler climates, who in the heck told you that.

0w oils also have much more synthetic base stock and usually have lower pour points

Just check out PDS's of various oils

Think of it this way...the first number in the equation is the start up viscosity. 0w has a thinner start up viscosity when compared to 5w or 10w. The second number is the viscosity at operating temperature. So 30 is going to be a thinner viscosity at operating temperature compared to a 40. I did a bunch of research on various forums and on www.bobtheoilguy.com . In my opinion, it seems like its always a safe bet to go with a 0w oil. If the oil is less viscous at start up, that means the engine can move the oil into the engine much easier than a thicker oil. This is the reason its highly recommended to use 0w oil in cold temperatures. For warmer temps, 0w is not going to hurt anything either. In warmer temps you can get away with a 10w oil because its not as cold and does not take as long to get the engine to operating temp. Now just because it says 0w, that doesn't mean its a thinner oil...is just thinner at start up. For example, a 10w-30 oil is actually thinner than a 0w-40 weight oil when at operating temperature. The 0w-40 is only thinner at startup. Again, this is so the oil can get into the engine quickly for those first few minutes at when being warmed up. At startup, this is where most engine wear occurs, so it makes sense to me to go with a 0w oil, especially so if you live in colder climates.

Now with all this being said, it comes down to brand as well. The German Castrol 0w-30 oil was the favorite amongst G owners and this forum. From research, it was because of being made in Geramy and set to European standards, that it performed more like a 40w oil. I decided to change to Mobil 0w-40 personally. I can't get the GC where I'm at and from the numbers, the Mobil 0w-40 seems similiar to the GC oil. On another note, I read somewhere that when a car starts to rack up miles, it might be a good idea to increase the oil viscosity as well. Another reason I went with the 0w-40. I'd be interested to know how the Amsoil 5w-30 or 0w-30 European Formula performs....hmmm....for now I'll stick with the Mobil 0w-40 for few oil changes. Seems to be working for me so far. And, this might have nothing to do with it, but its the oil that is used at Nissan when changing oil for the Nissan GTR. Says it right on the bottle too.

I just bought Castrol Edge Synthetic 5w-30 and a purolator filter. Tired of having Infiniti's 76 synthetic blend.

Based on the UOA table on my350z, I switched out my German Castrol for 5w30 Penzoil Platinum since it seemed to perform almost as well and was on sale for 25 bucks for 5 litres compared to 11 bucks per litter for German Castrol.