Just wondering if any of you guys/gals have any thoughts on using synthetic oil for the Northstar. We get some really cold weather here in the winter. The problem is I have 15K km'* (9K miles) on my car. I have heard from people that you have to make sure the engine is broken in otherwise the seals, rings, etc wont "set up" properly and the engine will use oil forever?? Any thoughts. Do I have enough mileage for it to be broken in?? Just want to make it easier on the engine when it is -40.

Never heard of that "breaking in first" thing, Don't Corvettes come prefilled with Mobil 1?

Either way, There'* a local salesman with a Caddy, We do his oil changes every three weeks like clockwork with Mobil 1 5w30. Runs perfectly in the shop.

I have 50,000 miles on my '04 and have run Redline 5w30 in it since day one. It doesn't use any oil.

I know what you're referring to with regard to "break in". I think a lot depends on the machine. For example, air cooled engines really may have to have some such break in period (my Harley is an example of that). However, I don't believe there are any issues with break in periods for any automobile I'm aware of -- just not a consideration any longer.

I switched to Mobil 1 in my 05 GXP at first oil change (actually was near to 5K). I use, and have used, Mobil 1 in my various cars with good results -- and also because it'* easy to find. (I'd love to give Royal Purple a try, but it'* a pain to get (no local dealers) and is significantly more expensive than even Mobil 1.)

IMHO, at 9K miles I can see no reason why you couldn't switch to a full synthetic. One additional thing I would say is be sure to also purchase a better-than-average oil filter. I mean, if you're going to run the synthetic for more miles than you likely would a petroleum-based oil, you want to have the best filter you can get. I also buy Mobil 1 filters -- but there are others (like AMSOIL) that are certainly just as good.

I've used Mobil One in our 2000 SSEi since it was new, change oil when the DIC says 40% life left (or 5,000-6,000 miles). 75,000 miles now, never uses oil, runs great. My 98 Vette had 72,000 miles on it when I sold it last year, same story. Using Mobil One in the new Vette of couse and will switch to it on the GXP on the first oil change.

As far as breakin is concered, here is what Mobil has to say.
http://www.mobiloil.com/USA-English/...ics/Myths.aspx

A Google search on synthetic oil break-in brings up a bunch of interesting sites, here is one of 'em.
http://www.stealth316.com/2-breakin.htm

If you got 9k on her thats good enough,
start running the moble1 now(with a AC pf-52 oil filter), i run it in everything i own.

10w30 in the summer

5w30 in the winter

Mobil 1 in my Aurora. I had the first batch in for about 5-6k miles, and just changed it again last week. Many Aurora owners from Aurora Club also use it in engines with various mileage, with no problems to date.

How important is it to use 5w30 in the winter? I kept 10w30 in mine, and this batch will probably be in there well into (if not all the way through) the cold months. My Aurora is garaged every night, so I'm not too worried about super-cold startups.

If your not too worried about real cold start ups 10/30 would be fine then,
but in MI. in the winter It gets pretty cold at night so i like the 5/30 to get things flowing faster.