As the saying goes, "you're mileage may vary". I've run regular (87) in it for a period of time, and premium (93). I get slightly better mileage with 93, and noticeably better performance at freeway speeds. Overall, for me, the savings at $3.00 a gal is about $200 annually running 93. So really its a wash. I can run 87, but I'm not really saving all that much. If I use 12 gal a week, it costs an extra $2.40 to use 93 octane. That's $125 a year more to run 93. And I make it up in better mileage.

 

do people realize that filling up a full tank with premium vs regular will only cost you roughly $5 more a fillup. I mean i only run 93 in mine but ive ran 93 in all my cars. Just better for it overall

 

I average about 50 miles per tank more with 91 octane gasoline without alcohol.

 

If you have even the slightest heavy foot, you'll want to run premium. The car is a dog off the line on 87 when driven hard. It's painful at $4.55/gal where I live, but I always regret putting regular in (which for some reason I do about once a year to remind me why I don't!).

 

hahah 379 , try 4.50+ here .. dont care though , i get knock with the low grade mud and the car is clearly happier with premium.

 

I have run all three grades in my 2.4 during the 130,000 plus miles i have on mine. There does seem to be a hair more power and mpg with 93 octane. But most would never know the difference

 

When I had my LT if I ran 93 it had better performance but 87 worked for fuel mileage. My SS on anything but 93 gets crapy mileage and for sure less power. Right now I am getting 27.5 on a 13 mile drive to work on average. I love my SS

 

Since I purchased the car in '06 I have used nothing but 93 octane. I have lived in mountainous regions for a good portion of the time I have owned the car and I noticed that 93 helped me keep lower engine temps as well as helped me get over mountains with ease.

Of course, the fiance drives it like its a BMW 5-series so any gas mileage savings we would see using 93 are negated. But the engine is in great shape, hasn't lost much power from original purchase (probably time to change the coils and spark plugs) and runs well.

I've been tracking the fuelups since I found Fuelly.com (129 so far; challenge was/still is my fiance and I remembering to save the receipts and/or write down the mileage) and its an average (over 129 fuelups tracked) of 26.8 MPG.

 

There IS a reason GM put that premium is recommended in it. They didn't do it for fun, the engine is designed for optimum efficiency with 93. Now, if you have a 2.2 it isn't going to make a difference. As for pure gasoline, you will see an increase as there is no ethanol in it, and ethanol lowers fuel economy. You won't hurt your car running 87 in the 2.4, but you won't get the best performance/efficiency out of it either.