Which Mobil1 for 03 Spyder?

My Spyder has 15k on it and I'm going to start using Mobil1 oil in it....which weight is right for my Spyder? The Mobil 1 site says 10w-30, but I believe my owner's manual says 5w-30. Which one is correct? Does the synthetic oil 'flow' better thus the 10w-30 recommendation?

Where do you live? I live in wisconsin and it all depends on the time of year for me what oil to run in it because of the tempature.

here is how it is said to go if it gets below 0 and not so much above 100 than use 5w30
if it hardly ever gets below 0 but is in the 100 range a lot use 10w30

One of the reasons is this when you start the car in colder temps the oil will take longer to get to the head and through the system if you use 10w30 compaired to 5w30 cold start with thicker oil can kill a motor over time that is why the above and below 100 is suggested.

That's true for a conventional oil. But the synthetics are a slicker better oil thus the reason for going up a grade. The oil will flow more freely. That's part of the reason that you hear of the increase in horsepower from people that have used fully synthetic oils.

i understand that they are "sicker more lubercating oil" but it is the sheer weight of the oil that makes it hard in cold start situation. What i pulled up was what the haynes manuel said for all oils synthetics and conventional oil.

Ya.. Thats why in Wisconsin I have to change my oil according to the season Granted it may not do that much becuase im sure there are plenty of people out there that don't do it that way and still have there cars running fine.. But just a preference that I do

oh they will run it's just that the motor life decreses for the fact that the head ring go with out lubercation longer while the motor is cold at startup.

Oh I wasn't denying the need for a lighter oil in winter I still agree with that I was only saying that with a synthetic I would go with a grade heavier than you would use if you used a conventional oil. I.E. if you were going to use a mobile 5W30 then use the Mobile 1 10W30 synthetic change oil grades as necessary due to season.

I live in central NY (30 miles south of Lake Ontario). Temps are quite cold in the winter, but it doesn't get below 0 much.
Not exactly sure which Mobil 1 to use yet...

Like I said I'd go with 1 grade above recommended factory. Cuz the factory recommends based on conventional oil.