Does Switching From 87 Octane to 91 Octane Bring Any Benefits For an LS3 Crate Motor?

Or should it? Simply watching the video below might help clarify some parts of the discussion, but the figures presented are only valid for that engine, an LS3 crate motor from BluePrint engines. As you may be aware, not all engines work just as well with all fuel grades, and some seem to run better on one rather than the other.

Not every dyno pull is the same as the other, and tuners will often make minute adjustments from one run to the next, and this case is no exception.

The goal was to see what the difference is between 87 octane, 91 octane, 110 octane (leaded race gas), 116 octane (leaded race gas), and E85. The results include the peak of performance for each fuel, as well as the average torque and horsepower for each.

The first two grades and the last one come straight from the pump, while race gas needs to be acquired separately. At this point, we should note that the motor used for the test has a carburetor, not fuel injection, as all modern vehicles have.

As you will observe, things are closer than they may appear when averages go, but the peaks are not that far between them. If you take a look at the cost of filling up with the more expensive grade, you quickly realize that getting race fuel does not necessarily justify itself if you go for a real pragmatic view that goes along the lines of horsepower gained per dollar spent.

For example, using nitrous is in the best possible position on this scale – but that is not possible everywhere, and that is an entirely different situation.

On the other hand, E85 can do wonders even on a naturally aspirated motor that is correctly adjusted to it, not to mention what it can do to a boosted motor. Watch the video below to learn more.