Why is octane rating important

N-heptane has a low resistance to knocking, even at very low levels of compression, and is assigned a rating of 0. Other fuels are assigned an octane rating based on the mixture of iso-octane and n-heptane that results in knocking at the same compression level as the fuel being considered.

Because knocking behavior varies with engine operating conditions, there are several different octane scales considered. These are both measured using the same iso-octane and n-heptane based method but under different engine operating conditions.

RON conditions are meant to reflect fairly stable cruising conditions. MON conditions are meant to reflect more challenging conditions such as high speeds or pulling a heavy load. This is called DON. Downstream capabilities View our downstream services. Gibbs, L. Anderson, K. Barnes, et al. Motor Gasolines Technical Review. Chevron Corporation. Thomas, J. West, and S. Oak Ridge National Laboratory. Prakash, A. Octane Response of Premium-Recommended Vehicles. SAE Technical Paper , doi Cracknell, V.

Natarajan, D. Doyle et al. Understanding the Octane Appetite of Modern Vehicles. West, B. Huff, L. Moore, M. DeBusk, and S. Department of Energy and the U. What octane ratings really mean for your car By: Akhtar Hussain Director of Refined Fuels Marketing, Refined Fuels in Fuel Efficiency Load up the snacks and crank up the tunes, because summer road trip season is officially here. Summer trips mean long hours on the road hauling heavy gear. Towing loads like boats and campers can be especially taxing on the family car.

Fuel grades like regular, plus and premium are dictated by their octane rating. So what do those different octane ratings at the pump really mean? Climate Change. Climate Feedback. Ocean Acidification. Rising Sea Level. Octane rating Figure 1. A gas station featuring five octane ratings, represented by the five different numbers on the pump. What is Cetane? What Does Octane Do?