How many octane is premium

Oh well. The Charger's manual says 87 octane will provide "satisfactory fuel economy and performance. Similar to the BMW, the Dodge's gains on the dyno 14 horsepower and 23 lb-ft of torque translated into negligible improvement in our real-world acceleration testing. Saddled with elephantine heft and eager to spin its rear all-season tires at launch, the Charger posted the same 4.

At triple-digit speeds, the higher power on 93 octane gave the Charger an advantage measured in tenths of a second. The Dodge also posted a 0. Just as important, the bellicose roar of the iron-block Hemi and the Charger's ability to reduce its rear tires to jungle-gym ground cover are unaffected by the fuel in the tank.

While Ford's EcoBoost F stands out as an obvious exception, the Dodge Charger's numbers make for a tidy summary of our findings. If you buy fuel with an octane rating above the manufacturer's requirement, you're likely to feel it in your wallet more than the seat of your pants.

How your engine constantly invites and silences engine knock to estimate a fuel's octane rating. Your car doesn't know the octane rating of the fuel in its tank. Instead, the engine controller calculates an inferred octane with closed-loop logic that continuously advances the ignition timing until it detects knock, which occurs when a portion of the fuel-air mixture ignites before the spark-plug-initiated flame front reaches it.

The further the computer can advance the timing without provoking knock, the higher the octane rating. During knock, the flame front travels through the combustion chamber up to 10 times quicker than the normal spark-initiated flame front. Left unchecked, these pressure waves can damage the head gasket, pistons, or cylinder head. But the occasional brief knock is a useful tool for checking that the engine is operating efficiently.

It's detected with one or more knock sensors bolted to the block to sense the oscillations created by the pressure waves with a typical frequency between 7 and 16 kilohertz. Stephen Russ, senior technical leader for gas engines at Ford, says this normal knock is usually detected and addressed within one or two combustion cycles and poses no threat to the engine.

New Cars. Buyer's Guide. Type keyword s to search. Learn More. Are you using a typical 2 diesel fuel in your personal truck to haul a camper or boat? Our premium diesel expert dives into the benefits of using a quality diesel fuel throughout spring, summer and fall to ensure your equipment is operating in top condition. 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. However, the majority of cars on the road today are optimized to run on regular gas. The detergent additives in your gasoline are far more important than the octane level, as they help clean your engine and optimize performance.

Each retailer offers a different blend of additives, used across all grades. When it comes to additives, some hold themselves to a higher standard.

They claim that lower concentrations of detergent additive can leave more deposits on engine components, including fuel injectors and intake valves. This, in turn, can lower engine performance and increase emissions.

Engines with a high compression ratio typically require higher octane fuel to achieve its intended level of performance, fuel efficiency and emissions. While you might save money on gas, your car will be less powerful and fuel-efficient. At the time, the U. At the same time, EPA and the U. The BTEX complex is a hydrocarbon mixture of benzene, toluene, xylene and ethyl-benzene.

Commonly referred to as gasoline aromatics, these compounds are refined from low-octane petroleum products into a high-octane gasoline additive. While some volume of BTEX is native to gasoline, it is also added to finished gasoline to boost its octane rating. The total volume of BTEX aromatics in finished gasoline depends on the desired octane value and other desired fuel properties.

When faced with the removal of lead as the primary octane provider in gasoline, refiners had two available alternatives, BTEX and ethanol. The refining industry invested in additional refining capacity to replace lead with BTEX, a high-octane petroleum refining product. As a result of its substitution for lead, BTEX volume rose from 22 percent to roughly a third of the gasoline pool by In premium gasoline grades, the BTEX volume content was as high as 50 percent.

In mandating cleaner fuels, through reformulated gasoline and other programs, EPA has reduced the volume of aromatics to between 25 to 28 percent of the conventional gasoline pool, though some health professionals question the safety of even these levels.

After the lead phase-out, there were early concerns regarding the BTEX complex. Today, health research indeed suggests that even very low-level exposure to the BTEX complex, from gasoline additives and other petroleum products, may contribute to negative developmental, reproductive and immunological responses, as well as cardio-pulmonary effects. Upon incomplete combustion of the BTEX complex contained in gasoline, ultra-fine particulates UFP and polycyclic aromatic hydrocarbons PAHs are formed, which carry their own adverse health impacts even at low levels.

Both UFP and PAHs have also been linked to developmental and neurodegenerative disorders, cancers, and cardio-pulmonary effects. Considerable attention has been given to benzene in fuel, as it is highly toxic. At the same time, the partial replacement of benzene with other aromatic compounds xylene, ethyl-benzene, toluene may not be sufficient in reducing exposure to BTEX's toxic effects. The other aromatics, such as toluene and xylene, are not capped.

Early automakers expressed interest in plant-based alcohol fuels, such as ethanol. Henry Ford designed the first Model T to run on ethanol. But, at the time, gasoline was a much cheaper fuel. During the oil embargo, regular unleaded gasoline prices jumped 57 percent and routine gasoline shortages also occurred.

These events, and the regulation of many air pollutants, sparked a renewed interest in fuel efficiency, electric vehicles, and renewable fuels such as ethanol, which were seen as ways to meet the new regulations and reduce petroleum consumption.