Octane Gas

I read somewhere that the higher octane used in your truck the better performance you get.. higher octane = more horse power .. is this correct? and if so how do i know what the highest octane i can use is?

Re: Octane Gas

For your boat?

Re: Octane Gas

no sorry 2000 ford F-150 4.2L V6.. shoulda said that first sorry

Re: Octane Gas

Unless you are getting spark knock on the 87 octane i doubt you will tell any difference running the 93 octane premium.Maybe a tad better fuel mileage.
The 93 won't hurt anything but power wise i don't think you will see any difference.

Re: Octane Gas

how bout inbetween like a 89 or something.. i figured i would give it a try. test my mileage etc. but i wanted to make sure before i go and mess up my engine running higher octane

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yea, the high test dosn't have more power in it, it just resists burning more than 87, so it only explodes under higher pressure.
it is actually less flamable than 87
it may actually hurt your engine if it is not reccomended for it

Re: Octane Gas

It depends on the engine ECU. Some engines are designed to use higher octane fuels to take full advantage of higher compression ratios and make "more" power, but. . . .

There are three approaches to avoiding pre-ignition or detonation.

1. Use "low" compression in the engine. It will make less power, but can use the less expensive fuels.

2. Retard the ignition timing. By igniting the faster burning low octane fuel later, "knock" is retarded.

3. Use a slower burning, high octane fuel.

There are advanced techniques to manage the flow, temperature and turbulence of the mixture in the cylinder that can further reduce "knock", but they are built in to the fluid dynamics and are fixed.

Some ECUs sense knock and retard the ignition to prevent it. This would happen if you used a low octane fuel in an engine designed for high octane. Retarding the ignition reduces power. This is what has created the myth that you get more power out of higher octane fuels. That is only true if the engine was designed for high octane fuel.

My ML requires 91 or higher octane. If I put 87 in it I would get less power and a sound rebuke from my MB Techs.

In engines designed for 87 octane the use of higher octane offers no benefit.

Re: Octane Gas

From personal experience, I ran 91 octane on a highway trip in my 1 year old minivan (it was a 97 Chevy Venture). I also then ran 87 octane in the same vehicle the following week on the trip back (1200 miles each way)

Got marginally worse mileage with the 91 octane. Don't know why. I believe in using what is cheapest and prescribed as the minimum for the vehicle.

Re: Octane Gas

Ya-da ya-da ya-da..............blah blah blah......................bottom line..
"In engines designed for 87 octane the use of higher octane offers no benefit."

Re: Octane Gas

Low octane gas in cooler weather is perfectly fine since the air is cooler. For every 10 degree drop in intake air temperature you increase horsepower by 1 or 2.

Higher octane gas burns slower (longer) then giving more power.

Want good MPG. Make sure your tire pressure is correct, air filter is clean and read the hyper miler tips on the internet. The Ford F-150 was never really popular for saving gas so you might have to work at it.

Re: Octane Gas

Unless you can advance your timing to take advantage of the higher octane it won't help.

Re: Octane Gas

JB, and LT are 100% correct, if your car is designed to use high octane fuel the owners manual and normally the fuel gauge will state high test only, if your engines compression ratio is less than 9:1 and programed for low octane fuel, you will just be wasting your $$$ using high octane fuel, in fact the cost at the pump is higher, and the engine WILL use more fuel because the higher the octane is less vioatol (sp) the fuel, so it takes more fuel to create the same explosion unless it's under a higher pressure. (compression)

Re: Octane Gas

xtraham said:

JB, and LT are 100% correct, if your car is designed to use high octane fuel the owners manual and normally the fuel gauge will state high test only, if your engines compression ratio is less than 9:1 and programed for low octane fuel, you will just be wasting your $$$ using high octane fuel, in fact the cost at the pump is higher, and the engine WILL use more fuel because the higher the octane is less vioatol (sp) the fuel, so it takes more fuel to create the same explosion unless it's under a higher pressure. (compression)

Click to expand...

Even Consumers Report says the same thing. Engine not design for high octane do not benefit from octane.

On cars from the sixties, we'd put higher octane to stop pinging, but since then the engines became tighter and computerized while gas additives also improved.