Gadgetory

now we fill up on gasoline and dribs and drabs over the course of a year so the price difference between premium and regular may seem small on a per visit basis yes the percentage difference between the two grades has declined due to the more rapidly increasing cost of a gallon of any kind of gas but the real cost spread of premium over regular has increased over the last six years in the u.s. put another way it used to cost you a little under 150 extra bucks a year to run premium assuming fifteen thousand miles a year and 20 mpg for your car but around 2004 began to take off and now it's a choice that costs more like two hundred and forty dollars a year real money let's find that if it's worth it now premium gas has this image largely due to marketing as being some happen to be a more explosive kind of fuel that blows off all this additional power in fact it's kind of the opposite Premium gas is high octane gasoline is is first a blend of many components that have many different properties and as such octane is one of those properties high octane allows you to compress the fuel more higher pressure higher heat without spontaneous combustion if you use regular or low octane gas in an engine that wants higher the mixture may combust it spontaneously in the cylinder before the spark sets it off that's called pre detonation or not that's the sound of your engine slowly coming apart it's hurting your engine there's a little mini explosion it goes on in this four cycle engine one of the cycles is compression when that goes out of whack there's an explosion that's not good it's a physical pressure way of traveling in the combustion chamber and you're actually hearing the result of that pressure we're knocking against metal parts in the combustion chamber these explosions they can hurt the internal in the engine they can hurt the catalytic converter of the engine the science that goes on when this 4 cycle engine does this combustion process it's pretty high-tech and one of those elements is out of whack it means it's not happening right now high compression engines were all the rage back in the muscle car and Pony car era and they're big and racing of course but lately car makers have been getting into high compression for everyday cars because they get more power out of little tiny engines that need less air and fuel to fill the cylinder each cycle in other words they create good power and use less gas now why does premium gas or high octane gas cost more is a very contentious area refiners will tell you they get less of it out of a barrel of crude than they do regular secondly they add different additives to it that will be used to increase the octane and those are more expensive than just crude itself the main additive back in the day used to be tetraethyl lead which increases the octane beautifully except it's led we don't do that anymore but that's what gave rise to the old nickname for premium they used to call it methyl with a removal of lead you removed an octane source and so other sources of octane or required that's it is modern cars as you probably know have sensors and computers and variable components all over them as a result they can sense not from running low octane gas and adjust the engine slightly to compensate for it knock it out but there's a limit to that adaptability depending on your car's design that's why you want to just check your car's manual it'll often tell you what octane level is okay and another one that's recommended also maybe one to avoid on the minimum side sometimes regulars find other cars say mid grade at least Premium at best others say premium only okay when you go to the gas pump you can look at the actual number button that you're going to select and look at the fine print and it will talk about a minimum octane number and under that it will typically say this sort of bit of math R + M / - that's research octane + motor octane / - or the average of the two so it there are single cinder engines that are used to calculate the octane of a given gasoline so the research number test is conduct at lower engine speeds and so it tends to be higher and then the motor octane is conducted higher engine speeds and tends to be lower you take the average of the two and you come up with what we call the anti-knock index and that's likely the number you'll see in a modern car manual US automakers have recently groused that octane in the u.s. is so low they can't make the kind of engines they offer in other markets smaller ones will even more power and greater efficiency just one point of clarification is that in places like Europe and South America where the opt-in numbers that people call for are in the high 90s 97 9 years that's only the research number right here in the US we do the research plus the motor and divide it by to put it in a nutshell you're safe using the lowest grade of gas that your car manual doesn't forbid that's your baseline typically especially in higher performance cars though there are tangible benefits to using the ultimate grade the premium especially if you want the full performance you paid for