Whats better to use for a blazer with 100k+ miles on it, SAE 5W-30 XL-7500 Synthetic Motor Oil (http://www.amsoil.com/products/xlf.htm) or SAE 5W-30 Synthetic Motor Oil (http://www.amsoil.com/products/asl.html) ? Thanks!

Save some money and go for Mobil 1. 5w30 with a good oil filter.

AC Delco
WIX
Napa Gold
Purolator

NOT FRAM!

the 7500 is the miles before u need to change or six months, so they say, i know amsoil has a 25,000 mile oil.

Honestly, save some money and get the Mobil 1.

Very good oil for the price.