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89 octane recommend, does it really make a difference?

RAM Patriot

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Higher octane gasoline, which is more stable, has no more energy potential than lower octane gasoline.

What octane gasoline should I be using in my truck?

Use only what the owner’s manual specifies. If your truck is designed to run on regular gasoline, or 87 octane. If your manual specifies higher octane fuel, such as 89, use the closest octane rating available at your gas station without going below the specified rating in your manual. (My manual recommends 89 octane for optimum performance and fuel economy)

What will happen if I use higher octane gas than I’m supposed to?

A few things. For one, you will be wasting a huge amount of money paying for high octane gasoline. Second, your truck will not run correctly, whether you notice it or not. Higher octane fuel requires more heat and more precision to burn correctly. If your truck is designed to burn 87, it will not burn 89 correctly. Third, your gas mileage will suffer. The inability of your engine to burn the higher octane gas correctly will cause your engine to produce less power and thus will require more fuel to perform at the same level.

What about using lower octane gasoline in a high octane engine?

In this situation, you will see negative effects that could be even worse. Using low octane fuel in a high octane engine will result in severely reduced performance because the engine will attempt to adjust to the lower octane gasoline. In extreme cases, or with prolonged use of low octane gasoline in these engines, pinging or pre-detonation can occur and can eventually destroy your engine. Pre-detonation causes very hot conditions in your engine and can melt sparkplug and pistons.

89_Octane.jpeg

What fuel you use in your vehicle is important. Make sure you always follow the manufacturers recommendations. Using a fuel other than what the manufacturer specifies will in no way help you save money, gain power, or do anything other than cost you money.

I use 89 or 90 non-ethanol fuel in my truck for all of the reasons stated above. (y) ♨️🔱
 

Buz

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I have no trouble with 87 not towing. Don’t need the extra power. Might try 89 one day just to see how much mpg goes up but it probably won’t be enough mpg gains to make it worth it.
I've tried. You will definitely, no question, not recoup your $$ with the 'mpg increase'. I've noticed almost zero difference in mpg between 87 & 89.
 

doolin64

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I've tried. You will definitely, no question, not recoup your $$ with the 'mpg increase'. I've noticed almost zero difference in mpg between 87 & 89.

It's more of a "feel good thing" you're doing for your truck, like catch can's and ceramic coatings. :LOL:
 

brian42

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Higher octane gasoline, which is more stable, has no more energy potential than lower octane gasoline.
The higher the octane the lower the potential energy in the fuel and the higher the flash point.

The higher flash point allows for advanced timing to spark closer to Top Dead Center (TDC) and still avoiding potential pre-detonation. The sooner the spark, the longer the combustion through the stroke, the more power the engine makes.

It was a lot easier in the "old days" when you manually adjusted your timing so you could run on whatever octane you wanted...or even adjust it for the weekend for some cruisin' fun. (y) 😉
 

Nova90

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I used 87 in my 2017 5.7Hemi Ram the entire 3.5 years that I owned it with no issues.
 

RAM Patriot

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So it's designed for 87 to 89. So we should be good either way.
My manual recommends 89 octane for optimum performance and fuel economy

Several members as have I have noticed slight pinging when running 87 octane fuel. Which puts more wear & tear on your motor.
 

HSKR R/T

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Are we sure about this? Seems the sensors would be monitoring this in real time.
Yes, that's how adaptives work. Long term fuel trims aren't changed immediately ornrheybwiuldnr be called long term. Same thing with long term knock retard. The adaptives are what the PCM uses as a baseline for any "real time" adjustments. So if your long term knock retard is retard is already pulling 2 degrees of timing, then that's where the PCM starts, and it will take several miles to overwrite that.
 

RAM Patriot

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The higher the octane the lower the potential energy in the fuel and the higher the flash point.

The higher flash point allows for advanced timing to spark closer to Top Dead Center (TDC) and still avoiding potential pre-detonation. The sooner the spark, the longer the combustion through the stroke, the more power the engine makes.

It was a lot easier in the "old days" when you manually adjusted your timing so you could run on whatever octane you wanted...or even adjust it for the weekend for some cruisin' fun. (y) 😉
Yes, Octane increases the resistance to ignite and does have a higher flash point.

But it does not decrease the potential energy, Instead burn time is extended allowing for a longer stroke with full compression throughout the stroke.

When the octane is to low, the flash point is decreased causing all of the fuel to ignite at the beginning of the stroke. This is why you have the knocks and pings, because the timing of the stroke is not in sync with the camshaft and ignition and the truck can only advance the timing so much to compensate.
 

Mountain Whiskey

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Because there is definitely a difference with "top tier" gas, and BP isn't the only one who is certified to label that way. It's more than just what detergents are used.
Like what more? I am not far from Dulles International Airport. The Colonial pipeline runs near me. It carries refined products from the gulf all the way up the eastern seaboard. There are multiple tank farms that it fills along the way for distribution in addition to supplying jet fuel to major airports. You will find that all the local stations run tankers from these tank farms to distribute to stations. All that gas is the same gas from the same pipe with different detergents and additives.

I would also like to know what top tier gas is in comparison to bottom tier. I have never seen an advertisement stating with a guy standing outside a baseball stadium yelling "Get yer bottom tier gas here! Bottom tier! Bottom tier gas here! Get yer bottom tier gas here!" Just does not seem like a smart marketing strategy.
 

HSKR R/T

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Like what more? I am not far from Dulles International Airport. The Colonial pipeline runs near me. It carries refined products from the gulf all the way up the eastern seaboard. There are multiple tank farms that it fills along the way for distribution in addition to supplying jet fuel to major airports. You will find that all the local stations run tankers from these tank farms to distribute to stations. All that gas is the same gas from the same pipe with different detergents and additives.

I would also like to know what top tier gas is in comparison to bottom tier. I have never seen an advertisement stating with a guy standing outside a baseball stadium yelling "Get yer bottom tier gas here! Bottom tier! Bottom tier gas here! Get yer bottom tier gas here!" Just does not seem like a smart marketing strategy.
Would you buy gas for your vehicle from a no name hole in the wall station with pimps that look like they haven't been serviced in 10 years?

Top tier rating also has to do with equipment and storage.

And there is no way the avgas and jet fuel for the airport comes out of the same pipeline as what you pump into your car at the corner has station
 

Mountain Whiskey

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Would you buy gas for your vehicle from a no name hole in the wall station with pimps that look like they haven't been serviced in 10 years?

Top tier rating also has to do with equipment and storage.

And there is no way the avgas and jet fuel for the airport comes out of the same pipeline as what you pump into your car at the corner has station
pline.png
At Newington, 15 different tanks can store 853,000 barrels of refined petroleum products. Gasoline is blended with various additives and ethanol at the Newington terminal, then trucked to gas stations and sold under different brand names.3

newington.png
the Plantation Pipeline ends at Newington, with tank farms viewed by travelers on I-395
Source: Google Maps


The Plantation Pipeline now ends at the Newington fuel distribution terminal in Northern Virginia. Two spurs carry jet fuel to Reagan National Airport (DCA) and Dulles International Airport (IAD).

the Plantation Pipeline extends north from Newington to Dulles Internatinal Airport, and Colonial Pipeline can also deliver jet fuel to storage tanks along Route 28 there
the Plantation Pipeline extends north from Newington to Dulles Internatinal Airport, and Colonial Pipeline can also deliver jet fuel to storage tanks along Route 28 there
Source: National Pipeline Mapping System, Public Viewer

 

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Mountain Whiskey

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Another informative article...


Other than knowing how to twist off the fuel cap, operate the self-serve pumps and complain about oil sheiks and prices, do you know how the energy that powers rubber tires, steel wheels, props and turbines gets to us?

"Getting Around" hopes to enlighten you.

I know you know that Exxon, CoGo's, BP, Gulf, Sunoco, Texaco, A-Plus, 7-Eleven, Mobil, Citgo and every other brand of gasoline sold in the Pittsburgh region travels thousands of miles to get here.

But did you know all brands are basically generic as they flow from refineries through the same pipelines?

Did you know regular unleaded gasoline, premium grade gasoline, diesel fuel, jet fuel, kerosene, propane and other distilled petroleum products also share the same pipelines to Pittsburgh and every other place?

Did you know there's a nationwide network of 114,000 miles of the underground pipes that collects crude oil from oil fields still in production in the U.S. and transport it to refineries for processing?

Did you know there's a related nationwide network of 85,500 miles of pipes, up to 48 inches in diameter, that then distributes the petroleum products from the refineries to communities such as ours for use in manufacturing, home heating and commercial, public and personal vehicles?

And.......

If everything is one big batch coming out of the same pipe, what's the difference in gasoline brands?

"Once the basic product fulfills the requirements that any refinery can meet, the individual companies put in additives specific to their sales," said Michelle Joy, general counsel for the oil pipeline trade group. "The additives can do everything from boost engine performance to clean the engine with a special detergent."

Amoco is the only gas segregated from other brands, she said. "It's a clear gas, an exclusive environmental product not made by anyone else. When we're moving Amoco, we're moving it as a separate batch."

If everything comes out of the same pipe, back-to-back, how do they separate the dozens of products and grades of gasoline making long journeys from refineries to markets?

A briefing paper from the Association of Oil Pipe Lines and American Petroleum Institute explains:

"The physical principles of hydraulics keep batches of liquid from blending and contaminating one another except where they actually touch. The 'interfaces' from the different shipments are separated out when they arrive at destinations and are re-processed.

"Sometimes batches are separated by metal 'pigs' or plugs that keep batches from touching. Pigs are also used for cleaning interior surfaces of pipelines to help prevent corrosion. Specially developed 'smart pigs' containing instrumentation packages are used to double check pipeline integrity."
 

Buz

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So it's designed for 87 to 89. So we should be good either way.
If you drive with a light foot and don't tow anything, then 87 really shouldn't harm anything.
If you're a lead foot and/or tow, then I would definitely recommend 89.
 

brian42

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Yes, Octane increases the resistance to ignite and does have a higher flash point.

But it does not decrease the potential energy, Instead burn time is extended allowing for a longer stroke with full compression throughout the stroke.

When the octane is to low, the flash point is decreased causing all of the fuel to ignite at the beginning of the stroke. This is why you have the knocks and pings, because the timing of the stroke is not in sync with the camshaft and ignition and the truck can only advance the timing so much to compensate.
I was confusing 'energy' with 'efficiency'.

I also learned that a 10% ethanol blend still yields 95% of the fuel energy of 100% gas.

If you drive with a light foot and don't tow anything, then 87 really shouldn't harm anything.
If you're a lead foot and/or tow, then I would definitely recommend 89.
If you want to increase your economy you should drive with a medium foot (accelerate smartly/purposefully to cruising speed).
 

RAM Patriot

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I was confusing 'energy' with 'efficiency'.

I also learned that a 10% ethanol blend still yields 95% of the fuel energy of 100% gas.


If you want to increase your economy you should drive with a medium foot (accelerate smartly/purposefully to cruising speed).
Your right 10% ethanol does decrease the BTU's of energy available.

But the major differences Between Ethanol And Gasoline are:

  1. A gallon of gasoline provides one-third more energy than a gallon of ethanol.
  2. Blending ethanol and gasoline at a ratio of 85 percent to 15 percent (E85), the blended fuel is nearly thirty percent less powerful than pure gasoline. Ethanol is similar in acceleration, power, and cruising ability, but ethanol miles per gallon are less than pure gasoline. (need more fuel to go the same distance)
  3. Ethanol causes damage to fuel systems and engines that pure gasoline does not. The most critical problems are water contamination and fuel separation. Ethanol attracts and absorbs water, including water from the air. When the ethanol absorbs enough water, fuel water contamination occurs in the trucks’ gas tank and that affects engine performance. If the truck sits for a while, fuel separation occurs; this is where the gas and water form layers in the gas tank and if the motor sucks up the water layer into the engine, and serious costly damage can occur.
 

50Front

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I have not noticed any difference in gas mileage between 87 and 89, i do feel that the engine transitions from V4 to V8 mode smoother with 89.
 

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