89 octane recommend, does it really make a difference?

[HSKR R/T]

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.

As long as you drive your vehicle and don't let it sit around a lot, ethanol use is a non-issue as far as separation and water absorption.

E85 is "less powerful" but being hugher octane rating, and less prone to detonation, you can throw more timing at it, which more than makes up for the reduced energy potential. which is why it's so popular for boosted or high compression engine applications. It might take more fuel, but the engine can make more power, safely, on E85.

 

[RAM Patriot]

As long as you drive your vehicle and don't let it sit around a lot, ethanol use is a non-issue as far as separation and water absorption.

E85 is "less powerful" but being hugher octane rating, and less prone to detonation, you can throw more timing at it, which more than makes up for the reduced energy potential. which is why it's so popular for boosted or high compression engine applications. It might take more fuel, but the engine can make more power, safely, on E85.

To actualize the full potential of ethanol fuel the engine has to be built around that thermal efficiency.

To do that you need a compression ratio 12:1 to produce a much higher thermal efficiency. Compression ratio is, thus, a key parameter to improve engine thermal efficiency when burning ethanol fuel.

Our engines are not designed to take advantage of ethanol fuel at 10.5:1 compression ratio.

That is the reason that our manual states not to use E-85 flex fuel or other ethanol blends greater than 15% in your HEMI engine.

 

[Quint]

I surprised that nobody has asked if they can run leaded gas in these Rams!

 

[theblet]

I’ve been putting jack daniels in mine and it takes off like a rocket!

 

[Mountain Whiskey]

I was going to give you credit for teaching me something new, but then you got ****y. So copy and paste skills done get credit.

Come on R/T, just messing around on a forum. You have to give some creds for the copy and paste skills. I didn't even try to eat any of the paste!

Back when unleaded gas was first coming out I knew a tanker driver that picked gas up from a tank farm. That was when unleaded cost more. He said it was funny because he filled up then went to another tank that had the lead addative. Strange how adding something to the fuel made it cost less.

Oil companies....

 

[HSKR R/T]

Come on R/T, just messing around on a forum. You have to give some creds for the copy and paste skills. I didn't even try to eat any of the paste!

Back when unleaded gas was first coming out I knew a tanker driver that picked gas up from a tank farm. That was when unleaded cost more. He said it was funny because he filled up then went to another tank that had the lead addative. Strange how adding something to the fuel made it cost less.

Oil companies....

Just like adding ethanol makes it cheaper because of how much ethanol is/was subsidized.

 

[RAM Patriot]

Just like adding ethanol makes it cheaper because of how much ethanol is/was subsidized.

Is subsidized, as a result, taxpayers have spent billions of dollars over the last 30 years subsidizing the production of corn ethanol, while at the same time creating unintended costs for consumers and the environment.

 

[theblet]

Sounds about right.

 

[HSKR R/T]

Is subsidized, as a result, taxpayers have spent billions of dollars over the last 30 years subsidizing the production of corn ethanol, while at the same time creating unintended costs for consumers and the environment.

Yeah, corn based ethanol is a very inefficient method. Much better options out there.

 

[Begrenzt]

Dealer put in 87 Octane when I purchased, but I've been using 93 Octane. Only about 3,000 miles so it really isn't broken in. Currently getting about 18 around town. Like someone said above, I'm using the 93 octane to avoid knock. Can't speak to MPG

 

[grimreefer]

Got a little curious so I did a couple/few "spirited" runs while listening intently and dammit... I heard a little pre-detonation. Was sitting on half a tank of 87 so I topped it off with some 93. She gets 89 from now on...

 

[RAM Patriot]

Got a little curious so I did a couple/few "spirited" runs while listening intently and dammit... I heard a little pre-detonation. Was sitting on half a tank of 87 so I topped it off with some 93. She gets 89 from now on...

You will not regret it, and your HEMI will thank you.

 

[CogitoErgoLevo]

I use 89 at regular gas stations and 91 at Costco because the only have 87 or 91 here in SoCal.
After reading this thread i was really curious about how much money I would save going to 87 instead of 89 and ran the numbers below.

If the price difference is about 20 cents per gallon between 87 and 89 AND you drive 15,000 at 17 miles/gallon
the difference between the 2 is $177 or $14.75/month more for 89.

To me the price difference is not worth using 87 instead of 89.

 

[HSKR R/T]

Dealer put in 87 Octane when I purchased, but I've been using 93 Octane. Only about 3,000 miles so it really isn't broken in. Currently getting about 18 around town. Like someone said above, I'm using the 93 octane to avoid knock. Can't speak to MPG

You would get better MPG on 89. 93 isn't helping you

 

[silver billet]

I use 89 at regular gas stations and 91 at Costco because the only have 87 or 91 here in SoCal.
After reading this thread i was really curious about how much money I would save going to 87 instead of 89 and ran the numbers below.

If the price difference is about 20 cents per gallon between 87 and 89 AND you drive 15,000 at 17 miles/gallon
the difference between the 2 is $177 or $14.75/month more for 89.

To me the price difference is not worth using 87 instead of 89.

Those looking to save a buck on 87 are missing the point. Using 89 is about giving your engine what it needs to run optimally/best, not about saving money.

I'm not about to penny pinch at the pump for a $50,000 truck which says "please give me 89". You may as well start throwing water in with your oil change to save a few nickles.

 

[Buz]

I use 89 at regular gas stations and 91 at Costco because the only have 87 or 91 here in SoCal.
After reading this thread i was really curious about how much money I would save going to 87 instead of 89 and ran the numbers below.

If the price difference is about 20 cents per gallon between 87 and 89 AND you drive 15,000 at 17 miles/gallon
the difference between the 2 is $177 or $14.75/month more for 89.

To me the price difference is not worth using 87 instead of 89.

Not sure where you live, but around me the difference between 87 & 89 is about 60 cents.
$530 yr
$44 mo.

 

[CogitoErgoLevo]

My post said: SoCal aka Southern California.

Most states have about 20 cents difference between 87 and 89 and that's why i used 20 cents as an example.

But even with 60 cents difference, you are only looking at $44/ month which is not much at all for 15000 miles/year.

 

[LakesAZ]

I use the half tank fill up method at Costco. One time 87 octane and at the half tank mark, fill it will 91.

 

[TangoFoxtrot]

I use the half tank fill up method at Costco. One time 87 octane and at the half tank mark, fill it will 91.

I've recently been doing the same. I've tried all different grades and multiple tanks and get different results all the time. I swear 91-93 seems to give me the best throttle response though, mileage meh it doesn't seem to matter what I put in it. I will say though 89 is usually the worst for me with regards to throttle response or what I feel, many time with 89 I feel like the engine will studder or just lag in response even with multiple tanks in succession. Maybe I just keep getting bad fuel, I do think that is a possibility. I don't personally know anyone who uses 89 in any vehicle, its either regular or premium. 89 prices can vary significantly, I've seen prices from 20 cents higher to 60cents. Costco definitely has the most consistent prices for 87/93, with 93 costing what other stations charge for 87. Doing the same blend as you I've noticed no issues, but then again 87 doesn't seem to cause me any grief either.

 

[LakesAZ]

I've recently been doing the same. I've tried all different grades and multiple tanks and get different results all the time. I swear 91-93 seems to give me the best throttle response though, mileage meh it doesn't seem to matter what I put in it. I will say though 89 is usually the worst for me with regards to throttle response or what I feel, many time with 89 I feel like the engine will studder or just lag in response even with multiple tanks in succession. Maybe I just keep getting bad fuel, I do think that is a possibility. I don't personally know anyone who uses 89 in any vehicle, its either regular or premium. 89 prices can vary significantly, I've seen prices from 20 cents higher to 60cents. Costco definitely has the most consistent prices for 87/93, with 93 costing what other stations charge for 87. Doing the same blend as you I've noticed no issues, but then again 87 doesn't seem to cause me any grief either.

I live at a high altitude, 5500 ft, so with the thinner air I can use 87 without any detonation. I have run multiple tanks with 87 without any knock, but a slight loss of power, which is why I do the half tank dance. Of course at my altitude I'm already losing about 15% of my horsepower so the blend helps keep it from additional power loss.