High Octane Gas?

[cccougar]

I have a 2014 2500 HD Ram with the 5.7 Hemi.. and have been putting reg gas in it. With the camping season upon us and towing every other weekend, should I be putting a higher octane in it? Will this help with performance? This is my first season towing- so I am very new to this.
Thanks.

[BenK]

This is a Laws of Physics or technological based discussion...all of the
'why', 'HOW2', 'cause & effect', etc, etc are in books/magazines/etc...heck
even here posted by folks who understand/know about this

This topic is all about how ICE's work, or the Otto Cycle and now factored
by some new science. Not new, but newly discovered science that has been there
waiting to be discovered since the beginning of time...

Things that has volumes of info on that apply (am sure missed a few...Turtle
can confirm n fill in):

• Knock
• Pre-ignition
• Flash point
• compression ratio
• CC (combustion chamber
• Octane
• Temperature
• Burn rate
• Ignition
• Ignition Timing
• ETC

[Blazing_Zippers]

We're returning from a mostly high altitude trip in Idaho-hot-pulling 9000 lbs. We keep records of our gas usage, and usually average 8.5 mpg, but this time we started with a couple tanks of the highest test gas we could find, and continued using non ethanol as often as possible. So far, the EVIC shows 11.4 mpg. One factor might be that we aren't driving too fast in the mountains, and speed kills our mpg. Is the extra 50 cents a gallon worth it? Maybe, maybe not. However, we're out to have fun!
See ya out here

[FrankShore]

Easy answer: Keep a mixture of 87 and 89 and 92 gas in your engine.

[Big1]

I have the same truck as you do and I have a diablo tuner to gain a little more tq and power, now I running 87 with the tuner and get a little more power but if I where towing heavy I will use the 89 or I can use the tuner and run 92.

[Grit_dog]

gcloss wrote:
The owners manual for my 2012 Ram 2500 with 5.7 Hemi calls for 89 octane, with a note that 87 octane can be used.

When towing I always use the 89 octane because there is a notable increase in performance from 87 to 89 octane.

Really?
That's interesting because my 6.1 Hemi will run like a scalded ape with 87 or the reccomended 91. No deto and the original plugs looked great at 80k mi when I changed them.
Gets the same mileage too.
To the OP, use whatever is reccomended. Newer engine management systems will compensate for lower or higher octane to a degree with timing, but no sense in waiting $ on higher octane than reccomended.
I'll run higher than reccomended in some higher perf engines either to compansate for potential bad fuel quality or detonation protection in 2 strokes, but realistically I'm wasting my $ too.
And at high altitude you can drop the octane requirement a little in naturally aspirated engines. Less air needs less bang to go with it. That's why you see 85 at the pumps in the mountains out west.

[Turtle_n_Peeps]

I like that higher octane burns colder

You read my mind Mich, you read my mind! :B

[cbshoestring]

Manual for my 2013 RAM 5.7 Hemi recommends 89. I use 89 all the time.

My Harley says minimum 92...I always use the highest the pump has to offer.

Once heard that higher octangs are better for small engines....I use premium in my lawn mower and my fuel mixes for the other lawn toys.

Wife asks why we put the cheap******in here Malibu....................... cause the book says 87 will do.

[noteven]

jfkmk wrote:

06Fargo wrote:

Claims from oil companies that grades of gasoline make any difference are hokum. Remember these are the people that prevented the 200 mpg carburettor from ever reaching the market!

Yes, but this can be offset by fuel line magnets and, if you have a carbureted engine, the Tornado fuel saver!

:S of course! I forgot about those!

Do they prevent carboning up? 🙂

[steve-n-vicki]

I liked the carbon part

[mich800]

Turtle n Peeps wrote:

marcsbigfoot20b27 wrote:
As usual, lots of mis-information.

The octane rating of a fuel is its resistance to auto ignite under pressure and heat.
Octane has no bearing on how much energy is in the fuel.
There is no more or less buildup with higher or lower octane.
If you do have carbon buildup, the top of the piston is what causes the problems, not behind the valves. The very tips if the carbon buildup will stay glowing under extreme load or lean burn and cause the mixture to preignite as the piston is going up, then the spark plug fires and both flame fronts meet and bang, detonation and piston damage.
Higher octane prevents the fuel from preigniting.

If an engine is designed for 89 then they have tuned that engine for max spark advance to handle that 89 under most conditions depending on the compression ratio of that engine. If you go wide open throttle up a big hill at 110 degrees with the AC on full blast pulling a 8000 lb trailer, you will probably exceed those parameters due to the high cylinder pressures and temps. Your computer will pull timing so the spark plug fires later, which lowers the cylinder pressures, but also lowers torque.

Therefore in extreme conditions like towing it makes sense to use the highest octane available to keep the fuel from auto igniting from the high pressures and temps. It allows the computer to give you more timing for better torque AND mileage.

A gasoline turbo engine I would use high octane for sure.

Gesus, thank you bigfoot for the correct info!

There are so many incorrect answers in this thread it just makes me :R

I like that higher octane burns colder :B

[Thunderbolt]

This is accurate info. I have never heard of high octane causing carbon like one poster said.The computer controls the timing and running higher octane allows the engine to advance the timing longer without detonation which doesn't actually make more power.With a computer tune it can produce a limited amount of extra power because it advances the timing more than the stock tune. higher octane fuel resists detonation period. It makes no more power, but allows the engine to reach it's potential.
In a high heat towing situation I could see it having a benefit.

marcsbigfoot20b27 wrote:
As usual, lots of mis-information.

The octane rating of a fuel is its resistance to auto ignite under pressure and heat.
Octane has no bearing on how much energy is in the fuel.
There is no more or less buildup with higher or lower octane.
If you do have carbon buildup, the top of the piston is what causes the problems, not behind the valves. The very tips if the carbon buildup will stay glowing under extreme load or lean burn and cause the mixture to preignite as the piston is going up, then the spark plug fires and both flame fronts meet and bang, detonation and piston damage.
Higher octane prevents the fuel from preigniting.

If an engine is designed for 89 then they have tuned that engine for max spark advance to handle that 89 under most conditions depending on the compression ratio of that engine. If you go wide open throttle up a big hill at 110 degrees with the AC on full blast pulling a 8000 lb trailer, you will probably exceed those parameters due to the high cylinder pressures and temps. Your computer will pull timing so the spark plug fires later, which lowers the cylinder pressures, but also lowers torque.

Therefore in extreme conditions like towing it makes sense to use the highest octane available to keep the fuel from auto igniting from the high pressures and temps. It allows the computer to give you more timing for better torque AND mileage.

A gasoline turbo engine I would use high octane for sure.

[thomasmnile]

TomG2 wrote:
The biggest gain is if you can find Ethanol free gasoline. It may not add much power but it helps fuel mileage a lot.

And to their credit, the new Racetrac and Wawa stations opening in Florida offer ethanol free fuel........at about a 50 cent/gal price premium. And, Wawa has an incredible $5 sub I hear........:B

[Samsonsworld]

TomG2 wrote:
cause a lot of bunkum to be written.

Stepped in that one time. Very difficult to get off your shoe.

[TomG2]

spadoctor wrote:
Been around the industry and the oil industry....using higher octane fuen then designed to use causes carbon buildup on valves....PERIOD

Been around the forums a long time and these kinds of subjects cause a lot of bunkum to be written.

[spadoctor]

Been around the industry and the oil industry....using higher octane fuen then designed to use causes carbon buildup on valves....PERIOD