Of course modern engines can adjust for lower octanes with the penalty of reduced performance. In most cases higher octane does not improve MPG but does provide a little better performance. This can be important when towing, hot weather, or turbo engines that are more sensitive to octane requirements. Owners manuals are the best place to see what is required and possibly recommended for your engine. I find I get higher miles per gallon when I use any gasoline that does not have ethanol in it.
When I use ethanol gasoline, my mileage drops into the 13 to 15 miles per gallon range. When using non-ethanol gasoline, my mileage goes up to the 23 to 27 mileage. What about 85 octane? Which is the best gas for ur car if a mechanic tell u u get the high percentage for ur car to help clean gas line out.
I thought that octane was gasolines ability to hold oxygen therefore at higher elevations where the air is thinner the gasoline cannot hold as much oxygen resulting in a lower octane rating. What AAA found out was that premium gasoline in a car designed for regular didn't produce better fuel economy, reduce pollution, or make your car go faster—in short, all it did was take a bit more of your money.
Join Now. New Cars. Car Culture. Type keyword s to search. Today's Top Stories. R for Getty Images. Sometimes in life, we are just wracked with choices. Over two billion dollars are wasted per year on premium gasoline. Leaded gasoline was the predominant fuel type in the United States until the U. Environmental Protection Agency EPA began phasing it out in the mids because of proven serious health impacts. Early in its use as a fuel additive, health concerns were raised regarding the use of lead in gasoline.
In , 15 refinery workers in New Jersey and Ohio died of suspected lead poisoning. As a result, the Surgeon General temporarily suspended the production of leaded gasoline and convened a panel to investigate the potential dangers of lead use in gasoline.
Despite these warnings, the Surgeon General set a voluntary standard of lead content, which the refining industry successfully met for decades. It was not until the s, following extensive health research, that the devastating health impacts of low-level lead exposure were established.
The health impacts of lead exposure in children include anemia, behavioral disorders, low IQ, reading and learning disabilities, and nerve damage. In adults, lead exposure is associated with hypertension and cardiovascular disease. Prior to the lead phase-out in gasoline, the total amount of lead used in gasoline was over , tons per year. Congress passed the Clean Air Act in , setting in motion the formation of the EPA and, ultimately, the removal of lead from gasoline.
EPA estimates that between and , 68 million children were exposed to toxic levels of lead from leaded gasoline alone. The phase-out of lead from gasoline subsequently reduced the number of children with toxic levels of lead in their blood by 2 million individuals a year between and The EPA is formed and given the authority to regulate compounds that endanger human health.
Lead damages the catalytic converters used in these new vehicles to control tailpipe emissions. Catalytic converters are still used in vehicles today. Lead is still used in some aviation fuels. Thanks to coordinated efforts, lead is now absent from gasoline in most of the world.
Following the lead phase-out in the United States, the oil refining industry chose to construct additional refining capacity to produce octane from other petroleum products, rather than from renewable sources such as ethanol. RFG has an increased oxygenate content, which helps it burn more completely. As a result, RFG lowers the formation of ozone precursors and other air toxics during combustion.
Petroleum refiners were not required to use any particular oxygenate in RFG, but by the late s, a petroleum product, methyl tertiary butyl ether MTBE , was used in 87 percent of RFG due to its ease of transport and blending.
In the Midwest, ethanol was a more common component of RFG. True go-anywhere autonomy will prove as elusive as finding satisfying vegan bacon. The trend we're really living is the story of smaller engines working harder, in everything from family crossovers to six-figure autobahn barges. Downsized but hardly diminished, many of these shrunken engines are more powerful than their predecessors, thanks to turbocharging, variable valve timing and lift, direct injection, and the advanced computer controls tying these all together.
Today's engines are so sophisticated that even mainstream nonperformance vehicles can benefit from running on higher-octane premium fuel. Vehicles such as the Ford Escape and Mazda 6 are advertised with power figures made on octane fuel, although both companies are quick to note that these vehicles will happily run on What automakers rarely say is what, precisely, are the benefits of paying for premium.
That ambiguity can be expensive. Raising the octane rating also known as the anti-knock index doesn't change the energy content of a gallon of gasoline. A higher octane rating indicates greater resistance to knock, the early combustion of the fuel-air mixture that causes cylinder pressure to spike. When higher-octane fuel is flowing through its injectors, the engine controller can take advantage of the elevated knock threshold and dial in more aggressive timing and higher boost pressures to improve performance.
To understand how higher octane affects acceleration and efficiency, we assembled a four-wheeled quartet sampling a broad spectrum of the market. The Honda CR-V stands in for a swath of affordable crossovers and sedans with its turbocharged 1. At the intersection of effortless speed and opulent luxury, the BMW M5 Competition squeezes horsepower from its twin-turbo 4. Ford's F is America's best-selling vehicle and is equipped here with its most potent engine, the hp EcoBoost twin-turbo 3.
We performed acceleration runs, mile fuel-economy loops at 75 mph, and dynamometer pulls, running each vehicle on two different fuels and completely draining the tanks in between. The differences likely would have been exaggerated by extreme summer heat, which exacerbates engine knock, but we sniffed out differences even with the engines huffing cool midwestern spring air. Even as it's sucking down as much as Honda asks for 87 octane and makes no claims that raising the fuel octane will lift performance.
Based on our testing, premium fuel might as well not exist in the CR-V's world. We could see this coming. During a similar Car and Driver test 18 years ago, an Accord powered by a 3.
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