When it Comes to Premium Gas, Does Your Manual Know Best?
YouTuber Jason Fenske answers the question with a heap of science.
Small-block V-8 power is part of the Corvette mystique. Chevy’s most recent versions of the LS engine prove you can have high-performance features like variable-valve timing from an overhead-valve engine, but does your Corvette’s fancy engine need to run on premium gas like some imported marques?
Engineering Explained recently tackled the question of whether it’s crucial to use premium in applications where the higher-octane fuel is recommended, but not required. Host Jason Fenske explains “from a cost perspective, there’s not really a justification for it.”
Timing is Everything
To see why this is the case, you have to understand some basics of the four-stroke engine cycle and how engine-control computers adjust timing to take advantage of premium gas. Jason sums it up nicely, saying “if you advance timing, you can make more power.” What is meant by that is that during the power stroke when the air/fuel mixture is being compressed, your engine can ignite the mix sooner.
Knowing that, the obvious question is: How much more power? Usually not much, but it depends on your car and type of engine. AAA recently released a study designed to reveal the answer to this very question in detail, and that is what Jason’s video goes into detail about after explaining the basics of timing.
If you own something that operates under extremely high loads and uses a lot of boost, such as a Corvette ZR-1 with the supercharged engine, you should probably stick to premium. However, in other applications, there’s really no requirement unless you’re looking to squeeze every last pony out of that LS.
Fenske does observe that “the larger engines benefited more from the premium fuel than the smaller engines,” probably because they were able to burn more of it by volume, so the increases were multiplied. LS engines are high-displacement, but in return for a few horsepower you’re not using on the road, you could protect your engine in other ways.
It’s your choice, but how would you rather spend your money: Burning it up at the stoplight grand-prix, or helping your ‘Vette live longer?