I just sold my 150k mile 2002 sentra (1.8) for $4200... I used GC 0W30 in this because it took less than 3 quarts so it was inexpensive. But now I'm buying my friend's salvage title 2004 Sentra SE-R Spec-V with 70k miles for $5500. I feel comfortable buying this salvage car because I saw it the day it came on the tow truck... the damage was minimal and I helped fix it so I know it's done right. Also I've seen him take care of the car, he used mobil clean 5000 every 3k miles. But this car takes more oil so I want to use a synthetic that I can get in a jug at walmart. What oils do the QR25 respond well to?? In my garage I have some supertech synthetic 5w30, Rotella T synthetic 5w40, and mobil1 extended performance 5w30.. because I do the manteinance on all the family cars, but I can always get a different oil for it. What do you guys know/recommend??