Lower octane fuel is prone to detonate. The knock sensor tells the engine management computer about this and the computer retards the ignition timing so knock is less likely. With this de-tuning, the engine also produces less power. The weaker the engine runs, the more fuel it must consume to do the work. Higher octane fuel allows the engine to run with more advanced spark and produce more power from the fuel it's using. Running stronger will allow it to make more power on the fuel it's using, thus, better mpg. The engine can run advanced timing up to a point and beyond that, even high octane gas will cause engine knock. Flex fuel has much less power potential (E85) than real gasoline and it burns up much quicker doing what you need it to do than regular gasoline. Flex fuel can be used in your car because the fuel system was outfitted with components that resist its corrosiveness. It is mostly alcohol which is made from corn (moonshine) and the advantage is that less oil is needed to supply a gallon of it. It's priced lower, but it burns up quicker. You will not hurt your truck using premium fuel, but it costs more. The engine can produce a bit more power on premium fuel than 87 octane since so much ignition retarding isn't needed to cut knock or detonation. Advancing the spark makes the engine act like it has higher compression and it will operate at higher potential.

Octane is a rating that expresses the fuel's resistance to turn to a vapor under heat and pressure. The low octane fuel vaporizes easily, the high octane fuel vaporizes less easily.

Your engine was designed to burn pump gas.

If your engine needs higher octane your owners manual will say so.

Your combustion chamber shape determines this.

If you have pistons and a valve area shape that requires

higher octane fuel, you would be told what it uses.

If the most economical fuel is causing trouble, your sensors can tell your system to make a timing response. It retards the timing to save itself. You can get this explained the way your manufacturer sees it by calling the dealer for your make.

Octane ratings today are not what they used to be when tetra-ethyl lead was added to fuel to raise its octane rating and prevent detonation. Premium fuel today does burn more slowly than regular, but also at a lower temperature, this produces carbon. So by burning premium fuel in your truck you will be depositing carbon on valves, pistons, etc. This will increase combustion pressured and force you to run premium all the time. Mileage will drop, and your operating costs will increase past the point of no return.

To answer your question -- YES, you will damage your truck like most high efficiency engines that require premium fuel to operate correctly, but develop stalling and hesitation issue due to carbon formation deposits on the backs of the intake valves that then alters air-fuel ratios while running.

The only thing that it will harm is your wallet.

But there is no power advantage to higher octane fuel, it's only a measure of it's tendency to pre-detonate. A high performance engine will usually have higher compression, so is more prone to pre-detonation, which can damage the engine. That's why some vehicles NEED the high octane fuel.

A less tuned engine can run on either octane, but with no more power, just more cost.

Every one of the above non-mechanics didn't consider your truck motor DOES have an anti-knock sensor which in the end reduces ignition ignition timing when it senses pre-ignition.

The higher the octane of the fuel the cooler and slower the fuel air ratio burns which prevents pre-ignition. You may or may not get any better fuel economy depending if you do all town driving or all highway driving.

Flex fuel means the engine will operate safely on 85% ethanol and 15% gasoline. Not all parts of the USA has this fuel.

Don't your truck have owner manul handbook? They should tell you about it. If it said 87 or higher then keep it at 87. Higher maybe better but not worth more $$$.

Nothing will increase the MPG on that thing. Higher octane fuel is a waste of money. It is built to run on regular or high ethynol percentage fuel. Should have done your homework.

The higher octane fuel will not help your mileage. Your truck is made to run good on 87 . Putting higher octane will not hurt your truck, just your wallet.

Don't your truck have owner manul handbook? They should tell you about it. If it said 87 or higher then keep it at 87. Higher maybe better but not worth more $$$.

The higher octane fuel will not help your mileage. Your truck is made to run good on 87 . Putting higher octane will not hurt your truck, just your wallet.

Okay, i just got a 2012 silverado two days ago, flex fuel(if that means anything) it has 42k miles. I didnt ask what the dealer filled it up with when i drove it off lot but since i put gas i put about half a tank of 89plus but i wana see if i can get more mpg or anything positive out of going up to 93super. Will i get more mpg if i switch from 89PLUS To 93SUPER gas? Or will it hurt the truck?

The higher octane fuel will not help your mileage. Your truck is made to run good on 87 . Putting higher octane will not hurt your truck, just your wallet.

The higher octane fuel will not help your mileage. Your truck is made to run good on 87 . Putting higher octane will not hurt your truck, just your wallet.

Unless your engine is designed for higher octane fuel, you will actually get less mileage.

Higher octane gas burns cooler in the wrong engine. This will lead to a faster carbon buildup and your engine will actually start to suffer from it eventually.

So using higher octane will cost you loss of mileage, higher gas prices, and carbon build up. It is an all lose situation.

Don't your truck have owner manul handbook? They should tell you about it. If it said 87 or higher then keep it at 87. Higher maybe better but not worth more $$$.

Don't your truck have owner manul handbook? They should tell you about it. If it said 87 or higher then keep it at 87. Higher maybe better but not worth more $$$.

The higher octane fuel will not help your mileage. Your truck is made to run good on 87 . Putting higher octane will not hurt your truck, just your wallet.

Don't your truck have owner manul handbook? They should tell you about it. If it said 87 or higher then keep it at 87. Higher maybe better but not worth more $$$.

The higher octane fuel will not help your mileage. Your truck is made to run good on 87 . Putting higher octane will not hurt your truck, just your wallet.

The higher octane fuel will not help your mileage. Your truck is made to run good on 87 . Putting higher octane will not hurt your truck, just your wallet.

Use whatever is recommended in the owners manual. If 87 octane is recommended and you use anything higher than that, you are simply wasting your money. Generally speaking, only high-end naturally aspirated engines and forced induction engines (turbocharged and supercharged) require premium fuel

the higher octane means that the gas will resist detonation to a higher point. if you are driving a flex fuel vehicle, it should be set up to sense the different gas. it should not be an issue.

Don't your truck have owner manul handbook? They should tell you about it. If it said 87 or higher then keep it at 87. Higher maybe better but not worth more $$$.

Don't your truck have owner manul handbook? They should tell you about it. If it said 87 or higher then keep it at 87. Higher maybe better but not worth more $$$.

Don't your truck have owner manul handbook? They should tell you about it. If it said 87 or higher then keep it at 87. Higher maybe better but not worth more $$$.

Neither, it will not harm it to put premium in it but it will only help if the engine pings on regular. If you don't have a persistant ping with regular gas then putting premium in it is only wasting money.

if it used a higher rated fuel it would be stamped on the odometer near the fuel guage , or on the gas cap

if it used a higher rated fuel it would be stamped on the odometer near the fuel guage , or on the gas cap

if it used a higher rated fuel it would be stamped on the odometer near the fuel guage , or on the gas cap

if it used a higher rated fuel it would be stamped on the odometer near the fuel guage , or on the gas cap

Don't your truck have owner manul handbook? They should tell you about it. If it said 87 or higher then keep it at 87. Higher maybe better but not worth more $$$.