What octane gas do you run?, Is higher always better ? Or just a waste of $$$ Options

[Demick]

I think the thing to take away from all of this is that the various types of pump gas are DIFFERENT. Premium is not better gas than regular - it is simply formulated differently in order to have different characteristics. Those characteristics allow it to be used properly in a higher performance (compression) engine than the regular gas, but premium is NOT in and of itself better or more powerful than regular.

Of course, that is how it is marketed, and how people perceive it. But like Jake said, your engine will perform better on one type of gas vs the other depending on your engines characteristics.

So people need to get over the perception that the higher the octane, the better and more powerful the gas is. You just need to run what is appropriate for your cars engine.

The fuel companies market the higher octane fuels as superior for a reason (it's also why they call it premium). They make more money from it. It doesn't actually cost more for them to formulate the higher octane fuel. It is artificially marked up in price in order to make more money. They can do this because they have created the perception that premium is really better gas and is better for your car. Also because those people who have the money to buy a car with a high performance engine can afford the extra cost of the premium gas.

I am only talking about pump gas here. Doesn't apply to race gas or avgas.

[Jake Raby]

As I satated above a couple of times every engine is different and even the climate impacts the fuel that will make your engine run it's best..

I will say that my Pinzgauer military truck is the only vehicle I own that will run its best on 87 octane, thats because it has 7;1 CR and was made to run on anything... I have gotten 2 bad batches of fuel in one year in that vehicle (12000 miles), but have only gotten ONE bad tank in the past 109K in my 912E that runs premimum 90% of the time and at least 89 octane all the time.

Its a gamble every time you pull up to the pump, when you see as many melted pistons as I do from engine teardowns you'd understand why 20 cents a gallon is worth the expense if thats the fuel that your engine runs best on...

I build engines specifically to run on 91-93 octane, many times the added efficiency that I'm able to squeeze from the combo will gain the customer at least 2-3 MPG and thats certainly worth more than 20 cents per gallon-

[Matt Meyer]

On a NEW engine with computer controlled timing and fuel, put the grade recommended by the manufacture.

A higher grade won't do anything but cause excessive emissions and maybe poorer fuel economy. A lower grade will probably cause engine knock which the knock sensors will pick up. The computer will then retard timing to protect the engine, costing hp and efficiency.

The knock sensors will "hear" knock long before you do, so the old saying, "use the lowest grade that doesn't knock," does not apply to the newer cars.