It's easy;

The first number shows cold temp flowability, the second shows warm or hot.

5w30 flows easier at a lower temp than 10w30 does, but when warmed up both are the same. Almost all the manufacturers are recommending at least 5w30 these days in nearly any gasoline engine, almost regardless of climate. It's also slightly better for fuel economy and emissions, which is why Honda and Ford have actually gone to 0w-20 and 5w-20.

I knew I wasn`t crazy, the W DOES mean winter
http://www.river2u.com/autoparts/oil.htm

Did I mention I'm new?

Yes, the W does stand for winter

no big deal Austin, , it was like one of those things that you can`t remember and by the end of the day it starts to make you feel like you are crazy

I jusy bought a 03 GP SE for my wife and I experience a knocking sound from its 3100. Its sounds more like a valve tap to me. I havent had any experience w/ these engines b4. It seemed alittle low on oil so I added some to get it to the right level on the dipstick. Seem to lighten up the sound a bit but it still can be heard from in the car slightly. If its true what is said about the piston slap w/ the 3100's thats what it could be. Ive been wondering what the hell it is since we've had the car about 2 weeks now. Its got 32K miles on it. The noise does seem to go away after it it driven for a few minutes so I thought an oil change would do it some good but the oil still has some good life to it. HercMan if you could come up w/ that article that would be great. Im going to have a Pontiac dealer look at it. Im not about to have an engine blow at 32K miles. If anyone has anymore info it be appreciated.

I experience the same with my '01 GP SE 3.1 engine. Was told by a GM mechanic that indeed, it's a "dry" start-up issue (engine sitting for hours). Goes away after a minute or two when the oil reaches all parts of the engine. I was told it's nothing to be concerned about, I do use 5W-30 Pennzoil.

So is there anything GM can do about it? That seems to me to be a design flaw. If those parts are knocking they are wearing faster since no oil is there at startup.

That's the reason for a class action lawsuit against gm for the engines built between iirc 96-02 not all engines 3.8Ls are exempt and 5.7Ls are exempt.

So since the suit is for 96-02 model engines, us w/ 03's are SOL, or was the problem somewhat corrected post 02? The knocking sound I get in my 3100 does go away after about 5-10 mins of driving. But its still not good for it to be knocking at all. HercMan anyway you could get that article on the lawsuit?

I'll see what I can find.

Cool...Id like to have some bullets for when I go and talk to GM about it.

http://www.bigclassaction.com/class_action/gm.html
http://www.prnewswire.com/cgi-bin/stories.pl?ACCT=sent_auto.story&STORY=/www/story/11-14-2003/0002058678&EDATE=FRI+Nov+14+2003%2C+03%3A04+PM

I couldn't find my original but did a search and found these. They all address the truck motors but iirc my original newstory said that it pertained to all vehicles with the said motors.

Thanks for that info, regardless of it pertaining to truck engines there is no difference between a 3.1 for a car or a truck. Im going to start watching the oil comsumption. If she starts using oil Ill know that I do have a problem. Like Ive said b4 the noise does go away after a few minutes of driving. I am concerned since I just bought the car and have no experince w/ 3.1s b4. I noticed in your profile you were in the USN. I take it your an airman judging by the pic of the C130 in your signature. Im also in the USN, a Seabee. Thanks again for the info.

Yep I am in the Navy. I'm an AM1 stationed at NAS Brunswick and that's one of the 5 C-130s we operate.