Long time lurker here, been reading for some time here after I saw patman's suggestion to this site from a post on ls1.com. Anyway, here is my question. I have a trans am with an ls1 engine. Currently I use gtx dino oil in it. The car is a weekend car and is stored about 4 months during the winter months here in chicago. Is it worth it to switch to synthetic? I change the oil before I store it and then when I bring it out of storage and then usually once during the summer months when I drive the car. I do not put a lot of miles on the car and this is why I am wondering if I should switch to synthetic. Also, I would like to do an oil analysis some time. I am getting ready to store the car and will be changing the oil soon, but the oil that is in there only has about 1500 miles on it, so would I be wasting my money doing an analysis on this oil?