I almost didn’t write tonight because I ate too much at dinner. I went with my parents to Pizzeria Mozza in Newport Beach. Their first available dinner reservation for tonight was at 10PM for a party of three, but compared to their location on Highland and Melrose in LA where reservations need to be made months in advance, I had no complaints about eating a late dinner. And it truly was worth the wait. Bacon, Yukon gold potato, Bermuda onion, and sunny-side up egg pizza. Prosciutto, Brie cheese, and arugula pizza. Wild mushroom and thyme pizza. Roasted mussels in a spicy tomato wine sauce. Tricolore salad. Chicken liver, caper, and parsley bruschetta. Banana gelato pie with candied hazelnuts. I died and went to heaven for a couple hours tonight, but now I’m back…kind of.
Earlier today I had cleaned out my closet and bedroom, donated a large chunk of my old belongings to Salvation Army, and ran around like a chicken without a head getting my errands done. It is quite inconvenient to run out of shampoo and toothpaste right before Christmas; I got stuck in traffic everywhere – shocker – and before I knew it my car started screaming at me about its low gas level. My mom generously offered to fill my tank for me (free food and gas…I love coming home). BUT, my mom and I have this ongoing debate about the importance of octane level, you know the 87-regular, 89-plus, 91-premium shenanigans. My car calls for 91, but my mom swears there is no real difference between the different grades of gas. But since I regularly started using only the 91 octane fuel in my car, I’ve noticed that it never has problems. Ever. So what the heck does octane level mean and does it really make a difference? Let me attempt to figure this one out so I can settle the argument with my mom once and for all.
It didn’t take more than a few seconds for me to realize I don’t know anything about engines. I might have drastically misinterpreted my research, but I hope not. For those of you in my same boat, here is an extremely brief overview before I really dig in:
Each cylinder in a car’s engine has a fuel/air mixture that is compressed by the piston. When it is fully compressed, the spark plug sparks the inside of the cylinder to give that cylinder the force is needs to create energy.
Octane rating is a standard measure of the performance of motor fuel. It is a measure of how likely a gasoline or liquid petroleum fuel is to self-ignite. Higher octane fuels correspond to higher activation energy requirements and thus it is harder for the higher octane fuel to reach the energy level required for it to ignite at an uncontrolled rate. High-performance engines are designed to run at a high maximum compression, which would cause a lower octane fuel to self-ignite prematurely due to the increased forces in those engines. Self-ignition leads to engine damage if it occurs during compression before the desired position of the piston in the cylinder as appropriate for valve and engine timing, and these problems are referred to as engine knock. Knock occurs when the peak of the combustion process no longer occurs at the optimum moment; the shock wave creates a characteristic “pinging” sound, and cylinder pressure increases dramatically. In the case of my car, my engine has 2.5 liter inline 6-cylinder engine, which requires high compression and leads to the dealers’ insistence on 91 octane fuel only, as stated in the owner’s manual. They also wanted $370 for an oil change…riiiight.
So there we have it, octane level really does make a difference on the type of engine you have. I’d rather be safe then sorry in this case, so I’ll gladly spend the extra few bucks a tank and go for the high octane. Sorry mom, I win this one.