[Kiara]

My 2013 ILX manual recommends using Octane 91 Premium gas. I have a 2.0 L engine & as far as I know only turbo engines require Octane 91 gas.

Is it really necessary to use Octane 91 gas since my engine is not turbo?

Also, the manual refers to Octane 91 as “Premium” whereas where I live it is Octane 89 that is referred to as “Premium” and Octane 91 is referred
to as “Super”. This is confusing to me!

 

[Slip_Angle]

The engine is high compression and as such needs 91 to perform at it's best. If you use lower octane the engine can detonate, which is not good for longevity. The difference between a tank of 91 and 89 is a couple bucks...

 

[Car nut]

My 2013 ILX manual recommends using Octane 91 Premium gas. I have a 2.0 L engine & as far as I know only turbo engines require Octane 91 gas.

Is it really necessary to use Octane 91 gas since my engine is not turbo?

Also, the manual refers to Octane 91 as “Premium” whereas where I live it is Octane 89 that is referred to as “Premium” and Octane 91 is referred
to as “Super”. This is confusing to me!

Use the 91 as recommended. My Hybrid even requires 91 octane gas.

 

[Kiara]

Thank you both for your help. My question was why a non-turbo engine requires 91 octane. It has nothing to do with the cost of gas or which type of fuel to use.

 

[Popeye]

High cylinder pressures created by turbo charging,supercharging or high mechanical compression ratios like that found in the ILX is the determining factor for octane requirements. Without the proper octane the engine will develop pre-ignition or "ping" which is detrimental to engine longevity. My S2000 is normally aspirated just like my ILX and requires 91 octane too