Just wondering what everyone who has the Northstar is using. I personally find the regular (87 octane) Shell to be just fine.

Chevron 91 ONLY!!!!!!!!!

I tried the 87 because I know it works fine but I really noticed the difference in mpg between it and the supreme. I usually use the middle grade, the 89. I like to use Cheveron with Techron. Don't know why but I just do.

prefer bp 93 but usually end up w/ speedway 89 or 92

I normally use 93 from bp or admiral but will go down to 87 or 89 if gas prices start to get higher.

Tip 4 the day: Do not:nono: sell your car for gas money. It's an oxymoronic thing to do.:histeric:

The owners manual suggests 87 octane or higher. Shell regular (87 oct) gives me good mpg's and could not ask for better acceleration. With all the driving I do I cannot see spending extra money for what???????????

On my V6 I put Citgo 93 Octane.

My old car was extremely picky. It only liked BP 93 octane.

I pumped Citgo 93 today at $2.36. Shell is stupidly expensive. Around here it's like $2.50 for 87, like $2.6x for 93.

My car seems to like the citgo 93 just fine.

I know I'll be fine with 87, just a habit of putting 93...

I found a very noticable performance difference between 87 and 93. I haven't tried anything else, and won't go back to 87 again.

I realize it's not really practical to pay the difference for greater acceleration, but if I was going to buy a car based on the price of gas, I wouldn't have purchased an STS in the first place. Even if I never use it, I want to know it's there for the asking!

89 is usually an acceptable compromise in those vehicles where higher octane is either required, or makes any discernible difference.