"Why do drag racers run special high-octane fuel?"
Do you drag race on public streets?
With the RPM range your engine typically operates at on the road, you really won't do anything.
When the Fusion is "top ranked" in 20 more years, then you can compare it to the Honda Accord that is on its 24th year and counting. Of course then the Honda will be on its 44th year, so you'll still have a lot of proving to do!
This is absolutely true. I see people commenting all the time that they put premium in cars that run perfectly fine on regular gas. All you are doing is wasting 20 cents per gallon if you do this. It really gives you no other advantage. If the car is tuned to run on regular, you should stick to that. Even your mileage won't really change, as the car is computer controlled and it is set up for a specific octane to run the best it can run. The Dodge Hemi cars suggest 89 octane, and they do not recommend raising it to premium as you can damage the engine if you run the wrong octane.
I mean really, does your 4 cylinder Fusion need a bump in hp so you can win at the redlights? Seriously? Buy a K&N filter; you'll get more performance. To go out and waste so much extra for something you don't need is ridiculous. I have driven many many cars over the years, and never have I had anything fail on one of my cars due to using the regular gas it was designed to run on. Stop buying into the hype about premium fuel.
Using premium fuel in most modern cars won't make that much of a difference. Reason being, that all cars made since the 80's use onboard computers connected to various sensors, that in turn continually adjusts the engine to run in different conditions. For example, there are sensors located on the throttle body, the crank, the airflow intake tube, the injector assembly, and so on. So if the engine is cold and fuel isn't burning as readily, the computer makes adjustments to the air and fuel intake automatically. In a carburetad car, the same cold startup would result in more fuel being unburned, thus creating more carbon and soot deposits. Additionally, newer cars can run lower grades of fuel more efficiently than earlier cars.
I've never used premium in any of my cars, and all of them at this point have well over 200,000 miles.
I keep track of the fuel mileage of every car I own very carefully. In running premium gas, I generally get not only a noticeable increase in power, but 1-2 mpg better mileage. The engine also stays cleaner and runs better for a longer period without a tune-up.
Any domestic will go 200,000 miles without problems, even if you run cheap regular gas and use non-synthetic oil. I bought a Dodge from my best friend that he had bought new. He took horrible care of it, used the cheapest gas and oil he could get, and changed oil at 10,000-15,000 miles. When I bought the car, it had 180,000 miles on it and had never had any problems. I drove it another 60,000 miles and sold it running like new. Most modern Ford, GM or Chrysler products can go 200,000 with no problems, even with horrible maintenance.
And yes, all my cars WILL run on regular. I just prefer that they run smoother, more powerfully and don't require tune-ups until at least 100,000 miles (and so far none have). I run a tank of premium through them at least once every month or so. If I go on a trip, I always use premium to get more power and a quieter, smoother running engine at freeway speeds. The extra mileage offsets the extra cost.
You must have a domestic if you need to run premium in it to make it run better. My Toyota runs perfect on regular in all driving scenarios. It is also great on gas!
Most Toyotas ARE great on gas. They burn none while sitting on the dealer's lots waiting for all the recalls to be done.
Oh another recall joke... ha ha ha! That is sooo 2010. Truth be told, I have not met one person with a Toyota who took it in for any of the recalls that actually needed any parts replaced. Another overblown, overhyped media circus. But whatever gives you new material for your jokes... LOL!!!
"You must have a domestic if you need to run premium in it to make it run better"
I always get a real laugh out of arguments that you can defy the laws of physics. You CAN'T. PERIOD. You always get MORE energy burning higher octane fuel. That's why they call it HIGHER octane. It doesn't matter if you burn it in a lawn mower or a Rolls Royce. More efficient burning of fuel means more power and more efficient use of fuel (i.e. better mileage). Next we'll see arguments that gravity is no longer applicable, or that the Moon is made of green cheese.
Maybe you should also consider that if an engine is built and tuned to run on a specific grade of fuel, you shouldn't mess with it. To run super unleaded, means you are burning at a hotter temperature, which causes more wear and tear on vital engine parts designed to run on regular gas, which can lead to premature failure.
Also, with complete computer control of the fuel system, the engines of today run at optimum levels on the recommended fuel. If you change from regular to premium, your engine will adjust to it and still run about the same. You aren't going to gain a whole lot of anything really. The only law of physics you are abiding by is how fast your wallet shrinks when you use premium fuel in any modern car that doesn't require it. It is purely and simply a waste of money.
That's not quite how it works. Higher octane doesn't mean a more efficient burn, it means a slower, more controlled burn. High compression engines (and some highly worn engines) require premium because if the burn is too rapid and uncontrolled, the fuel will detonate improperly. It's just to prevent detonation and knocking, there's no other purpose to it. The compression ratio in an I4 Fusion just isn't enough for the engine to need premium gas, and besides; It's been tuned by the factory to work at a regular octane rating. Unless the compression has been altered, or the engine is really old and starting to knock, you're wasting your money.
Here's the idea: The reason turbochargers, superchargers, intakes, etc, work is because they force more oxygen or denser air into the engine. When this happens, the combustion can't be rapid, or the engine will knock, detonate, or worse. The same goes for high end, high output cars like Porsches, BMWs, Ferraris, etc, because they have high compression engines. Higher octane rating or content means that the fuel-air combo burns slower, not that it will release more energy when burning. A 4-cylinder Fusion (or maybe even the V6, for that matter) won't have high enough compression to make a noticeable power difference.
As for efficiency, the ECU determines how much fuel goes in, not the fuel itself. Just because you used 91 octane doesn't mean it will magically decide to use less of itself. 1-2 MPG, by the way, is barely enough to register as a margin of error; I could get that same increase by taking off my roof racks.