Is it worth the extra money to buy premium unleaded gas vs. the cheap stuff?

if your car requires premium, you can’t use a lower grade…it will cause damage to your engine…

shorten your engine life.

Premium gas should be used for this vehicle. As required by the manufacturer (warranty requirements). Gas prices are lower than about 4 years ago too. Checked the news lately? Save on gas now…pay on car repairs later. Performance will suffer. Higher tail pipe emissions due to poor engine performance. Bad for the already suffering environment. Hybrid cars are good for some consumers(AKA car owners/drivers (although it doesn’t count to you.) Hope I answered some of your questions here friend.

Best wishes.

No, use premium as directed.
You can make more engine horsepower
if you increase the piston compression.
But regular gas will detonate to soon and ping
will be heard. This is harmful and hurts the engine.
Premium gas requires more heat and
pressure for combustion than regular gas.
The pump should say high compression
rather than ‘premium’ which suggests a
better grade of gas. More oil is needed to
make it, and costs more.

If you’re wondering whether you can here’s a simple test: let the gas run down as low as you possibly can without running the tank bone dry. Put about 1/4 or 1/2 a tank of a good regular 87 octane gas in it (preferably one that is a “top-tier” gasoline like shell, conoco, etc…) and run it like you would normally run it. If you hear “pinging” (a light sounding spark knock). If it sounds like “knock,knock,knock,knock” when you accelerate, then you need to raise your octane level and top-off with a 89 or 91 because your PCM can’t compensate for the lower octane level.
Personally, I don’t think you would have any issues with using 87 octane. All it will do is your PCM will compensate by richening the mixture of fuel to compensate for the lower octane fuel. It knows that you put it in there, but I just can’t see that it would hurt anything.
My uncle ran E-85 in his Impala SS with a turbo for a while, so I don’t see any harm in trying the 87 out and seeing if it works out.

If it says to run premium do it, to whoever said that you unc was running e-85 in a turboed car, yeahhhh they make a very good combonation my buddys turbo DSM had a retro kit to e-85 and got another 35 H.P. from the switch. the octane of e-85 is like 109! Your engine is most likely using forced induction, that is a turbo or supercharger, or for some silly reason it has high compression out of the factory. in anycase, if you dont use a higher octane fuel you will experiance detonation, and thats no good, to say the least, it can ruin your engine. Also if it says to use premium, then thats what it is designed to run on, so that will give you the best fuel economy, would you rather save 20 cents on that gallon of fuel or get an extra 5 miles out of it? Just a way for you to justify it, trust me, i drive a turbo dsm and have to run premium, i feel your pain!

Otherwise the engine will “knock” and be gradually damaged by lower octane fuels. You need to follow the manufacturer’s recommendation on this one.

use what the manufacturer recommends or pay the price down the road.

There is no advantage to using a higher octane gasoline than your manufacturer recommends, but there may be deficits from using a lower octane than they sugest.

You’re getting too many responses from people that do not have facts. I’ve had an FJ Cruiser since Feb ’07, and have alternated between Premium and Regular. I try to run down the gas gauge to E before switching, and that’s about all the attention I pay to it. At some point during 2007, Toyota released a technical service bulletin for the FJ Cruiser (your dealer has a copy) announcing that Premium fuel was not strictly required, and that the vehicle would operate without harm on regular fuel. The 2010 models allegedly no longer even state “premium required” on the gas tank cover, but I haven’t verified this. Although premium costs more, it’s generally worth it. Many FJ owners, including myself, have measured fuel economy under regular and premium using a ScanGauge2, and there is a couple of mpg difference between regular and premium. Depending on the price difference, it usually comes out to be a wash (regular being cheaper but you burn it faster with lower mpg). I tend to go with premium now because of the noticeably engine performance and responsiveness difference.

In my experience, you really need to follow the manufacturer’s recommendations for the type of gas to use. It will affect performance and mileage. When I had a high maintenance car, I never dared use anything but premium. Yes, it’s worth it. But here’s the Straight Dope on the subject:

Dear Cecil:

In this time of high gasoline prices, the Teeming Millions need your guidance (well, at least I do). What is the difference between premium and regular gas, and is this difference worth the extra money? I normally put premium gas into my car because I don’t mind paying two or three extra dollars at the pump. Am I being scammed by the gas stations, or is the benefit to my car worth it? –Jeff, via e-mail

Cecil replies:

Not to introduce a radical concept, Jeff, but have you tried reading your owner’s manual? If it says to use premium, my advice is to use premium. If it says regular, use regular. The fact that your note indicates no acquaintance with such matters suggests that you may in fact be a scam victim, assuming by this you mean “someone who believes what he hears in commercials.” I have a hard time working up much outrage over this deception, since discovering the facts requires so little effort. If you don’t mind paying the extra money for no reason, don’t expect the oil companies to suffer any pangs accepting it.

In most of the U.S., regular gas has an octane rating of 87, midgrade gas is 89, and premium is 91 or 92. (Octane ratings are lower in the mountain west due to the effects of thin air on internal combustion.) Contrary to widespread belief, the octane rating doesn’t indicate how much power the fuel delivers; all grades of gasoline contain roughly the same amount of heat energy. Rather, a higher octane rating means the fuel is less likely to cause your engine to knock or ping. Knock, also known as detonation, occurs when part of the fuel-air mixture in one or more of your car’s cylinders ignites spontaneously due to compression, independent of the combustion initiated by the spark plug. (The ideal gas law tells us that a gas heats up when compressed.) Instead of a controlled burn, you get what amounts to an explosion–not a good thing for your engine. To avoid this, high-octane gas is formulated to burn slower than regular, making it less likely to ignite without benefit of spark.

The majority of cars are designed to run on regular gas, and that’s what the manuals tell the owners to use. Higher-performance cars often require midgrade or premium gas because their engines are designed for higher compression (higher compression = more power), and regular gas may cause knock. If your car needs high-octane gas, the manual will say so.

Using high-octane gas in a car designed for regular accomplishes little except more rapid combustion of your money. Some refuse to believe this, claiming, for example, that premium gives the family Toyota better mileage or more power. These people are in dreamland. Others say premium is purer or contains detergents that will cleanse your engine of uncouth deposits. Likewise misguided thinking–government regulations require detergents in all grades of gasoline. (BP Amoco, I notice, asserts that its premium gasoline contains more detergents than legally required; if you think that’s worth 20 extra cents a gallon, be my guest.) Some automotive types claim that using premium in a car designed for regular will make the engine dirtier–something about deposits on the back side of the intake valves. I’ve also heard that slower-burning high-octane gas produces less power when used in ordinary cars. Believe what you like; the point is, don’t assume “premium” means “better.”

Occasionally you get some genius who takes the opposite tack–he spends an extra 10 or 20 grand buying a high-performance car, then decides he’s going to save three bucks per tankful using regular instead of premium as specified. He figures as long as the engine doesn’t knock he’s OK. Wrong, carbon monoxide brain. Car engines nowadays contain knock sensors that detect detonation and automatically retard the spark to compensate. The delay means maximum gas expansion occurs when the piston is farther along in its downstroke and thus there’s more room in the cylinder head. This reduces peak cylinder pressure, eliminating knock but also giving you less power and poorer mileage.

You may ask: Don’t knock sensors make it hard to tell when an old car needs higher-octane gas? Years ago, when your beater started pinging on grades or under acceleration, that was the sign that carbon had built up in the cylinders, increasing compression, and it was time to switch to high-test. Now the knock sensors compensate, which seemingly might conceal the problem. Don’t fret–today’s fuel injection systems precisely meter the fuel-air mix, resulting in fewer unburned hydrocarbons and less carbon buildup. If you’re still concerned, I’d say it makes more sense to spend $6 on a bottle of carbon clean-out juice than an extra $150 a