LOL didn't realize these guys were posting- almost said to solicit jr_ss' input since he lives in Failorida
My from the hip thought is that there are fuck-tons of oil-related topics (damn it- someone already said that too haha).
HOWEVER, I'm at work and kinda bored
10W30 is perfect for Florida and pretty much any other climate between 60* north and south latitude. If the motor hasn't been recently rebuilt, stick to any reputable synthetic, change every 4mos or 3000-5000mi (whichever comes first) and enjoy. If it HAS been recently rebuilt, use regular non-detergent SAE 10W30 for the first 1,500-2000mi (with an oil change at 500-ish) then switch to synthetic.
Anyway... No need to overthink it- For your SR, nearly any synthetic 10W30 is a perfect and economical choice for it to run strong & last; the brand is irrelevant so long as you use the recommended oil type & weight. 15W40 probably wouldn't hurt it, but probably isn't the best thing for it.
I have a 400+hp fully built SR; I use 10W30 and will never switch unless someone from SAE (Society for Automotive Engineers) gives me a goddamned good reason to do so. The key is doing regular and preventative maintenance... and using sound maintenance practices.
Although I have my own 2-3 choices of oil brands, my car is not a daily driver so I tend to splurge if you know what I mean...
BTW, jr_ss' car is AMAZING & worthy of 5W liquid gold if it would make his motor happier... But his car is not a DD & his engine is so far from stock... so his choice of oil is based on very different parameters
For general, daily driver purposes- If it ain't broke, don't fix it- Stick to Castrol...