Owners manual says use octane 87 or higher

[GMBoy]

Originally Posted By: Linctex
Originally Posted By: GMBoy
Why all the trouble mixing 1/2 of 87 and 93 to get 90? Just press the 89 button and save all that unnecessary work.


Because the cost per octane number is ridiculous, that's why.

It's cheaper to blend.



True - Cheaper by $2. Shell near me is 2.19 for 87, 2.69 for 89 and 2.99 for 93. If you took 20 gallons to fill up it would cost you $51.80 split 10 gal 87 and 10 gal 93 or $53.80 straight 20 gal of 89.

 

[Gary]

Originally Posted By: Alex_V
My Cruze is a port-injected gas, turbo I-4 with 9.5:1 compression - it's technically an 87 engine but the results every time I've put regular in it tell me it likes 89 or better a WHOLE lot more. Run at least a full tank, or several, of 89 or premium in it, then pump a bunch of regular in it and see if you notice a difference in idle quality and acceleration.


The higher is useless if 87 spec'ed doesn't necessarily apply to turbos as you've noticed. You may have even more power / response at 93. I go for that over watching MPG.

 

[A_A_G]

Originally Posted By: ARB1977
Use what the manual calls for.


Yeah...that would be great if the manual was a little more detailed...

"Fuel recommendation: Unleaded gasoline with pump octane number 87 or higher required"

It mentions nothing about why a higher octane should be used.

 

[Nick1994]

Originally Posted By: A_A_G
I don't mind running 89 since I already do in my two other vehicles. I'm more worried about getting the best fuel economy out of it.


The average cost of 87 octane fuel is $2.53 per gallon and 89 octane fuel is $2.81. A difference of $0.28 per gallon, or 11% more. If you get 31 mpg with 87 octane, you’d need to get 34.4 mpg on 89 octane just to break even.

It’s like driving a diesel vehicle trying to save money, in some instances it can happen, but the fuel cost is so much more, it better get WAY better fuel economy to start making sense, as far as saving money on fuel.

 

[SilverFusion2010]

Try it, see what the car does. It depends on how it’s programmed

 

[circuitsmith]

My Matrix runs a little peppier with 89 octane when the ambient temp is above 90F.
Doesn't improve MPGs though.
On a road trip to see the eclipse I got to run some 89 octane ethanol free (cheap in South Carolina) and got 40 MPG.