the manual says use 91 octane in 2.4`s but 87 is o.k. which do we tend to use. 89 seems to get stronger low end and better mieage(not a whole lot}

 

The computer on these scales back various settings, timing mostly, to accommodate lower octane fuel. The higher the octane the more power they can produce and some have found better mileage with higher octane as well. Sometimes that better mileage equals out the increased cost of the premium gasoline..... and you have full HP and TQ the engine was designed for.

I run Sunoco 93 octane at all times.... I'll sub a different brand if I need to but always high test.

 

i would go to 93 but rising cost makes me cringe

 

Understood......

 

nothing but premium here

 

tntwolt-

There are several 2.4 owners here that have posted using reg 87 & mid-grade long term & posted to have no ill efects..

I prefer 93, but do agree prices are crazy..

93 today is 3.79 @ Sams Club.

Edit: THE OM states ON 5-5, you can use 87 regular, but you might hear a spark knock. If you do hear this, go up a grade of gas asap.. Otherwise you could damage the engine.

 

Premium

 

You don't really have a choice SS.. Do ya..

 

mid grade works but no go.

 

I have been running 87 mostly in my 2.4L HHR for 5+ years and have averaged 30+ mpg, but I drive like and old man. I saw no difference in mpg running higher octane except a lighter wallet. I have tried pure gas, 93 octane, 89 octane and saw no mpg improvements. Since I don't push the HHR, performance is not a high priority, however good mileage is and $0.20-0.25 a gallon for cheaper gasoline is a good savings.