Ram 6.4 Hemi on Reg Gas

[JohnWedell]

Have the truck in my sig. I am running it on mid grade gasoline but wondering if anyone is using regular. Also will be pulling the trailer to Florida.

[curver900]

what is the recommendation? My 6.2 recommends premium..... but can run on regular but the mileage goes down and the performance does as well.

[JohnWedell]

Originally Posted by curver900

what is the recommendation? My 6.2 recommends premium..... but can run on regular but the mileage goes down and the performance does as well.

Regular and recommends mid grade

[curver900]

for towing use the recommended octane.. you can use the lower octane in a pinch, but you shouldn't use it if you can help it...

[smurfs_of_war]

I run my 6.4 towing on regular 87 pulled from a crappy gravity feed tank. No issues, no knock. I tried running midgrade for a while and found no evidence of improved mileage or power. If there was, it was unnoticeable. If mid grade or premium was available readily I may use it, but it's not necessary. If it was going to cause damage there would be a disclaimer noting it.

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[jloco]

My 2017 Chevrolet Silverado 5.3 states 'minimum octane of 87 or higher' It goes on to say use 'Top tier' fuels. Top tier being brands that add detergents to meet the 'top tier' spec. Fuel detergents are important to mitigate deposits on injectors in GDI engines.

I never buy fuel from one off gas stations to save a nickel/dime either because I don't know what's in it.


I prefer to use mid grade (89). The truck just seems to run better with it.

[Wannabe]

Originally Posted by smurfs_of_war

I run my 6.4 towing on regular 87 pulled from a crappy gravity feed tank. No issues, no knock. I tried running midgrade for a while and found no evidence of improved mileage or power. If there was, it was unnoticeable. If mid grade or premium was available readily I may use it, but it's not necessary. If it was going to cause damage there would be a disclaimer noting it.

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X2. I've run a few tanks of 89 through and didn't notice a significant enough mpg or performance difference to justify the cost. I've got 25k miles with about 10k towing and am happy to run 87....

[DocBrown]

Variable grade gas vehicles can and will vary in performance with different grades of gas. They are designed to run at peak performance at the higher recommended grade. I have owned 2 such vehicles over the years, one being my current HHR. I get slightly better mileage with premium gas in the HHR. When gas was $4 a gal and premium was only $.20 more, I saved about $100 a year running premium. No brainer. At $.40 more per gal and $2.45 for reg, it's not worth it.

For your truck, it's designed to run at it's best performance with mid-grade. If it was mine, I'd run mid-grade for towing and regular for daily driving.

[wwt]

I've been using mid grade during summer towing season and 87 during winter.
If you need max pulling power use 89. If you use 87 and the engine controller senses knocking it will retard the ignition timing which will reduce power. But ,as others have said, the power difference is hardly noticeable.

[Mad Cow]

Originally Posted by jloco

My 2017 Chevrolet Silverado 5.3 states 'minimum octane of 87 or higher' It goes on to say use 'Top tier' fuels. Top tier being brands that add detergents to meet the 'top tier' spec. Fuel detergents are important to mitigate deposits on injectors in GDI engines.

I never buy fuel from one off gas stations to save a nickel/dime either because I don't know what's in it.


I prefer to use mid grade (89). The truck just seems to run better with it.

The gas at a name brand is the same gas at a mom and pop. It all comes from the same local fuel terminals. And that terminal fuel comes from a variety of refineries, not all the same brand. Now, different stations will have different additives fed into the stream when a tanker is loaded, but the gasoline is the same stuff. In my over 5 million miles as a commercial driver, that included some time tanking fuel. Even premium is just the same regular gasoline, but with octane boosters added when the tanker fills up at the terminal.

I am cheap. I have no problem getting fuel at a high volume no-name place to save a few cents a gallon. The key being.... high volume. High volume fuel outlets will have lower risk of fuel contamination.

[2nOZ]

Just looked through my owners manual for my 2017 F250 and it says a minimum of 87 octane but 91 when towing.

[SkyBound]

I notice a dramatic difference in mileage and power when running premium versus regular - to the point where I am considering running premium year round now as opposed to just for the towing season. Mind you my truck is tuned and any forced induction engine is better off with higher octane.

[Mad Cow]

If the numbers work, then go for it.

I look at what I get on E10 regular with my GM 2500. On E10 I average about 14 mpg for all miles. 16-17 highway. With E10 going for $2.39 a gallon in my area, that equates to about 17 cents a mile on average 14 mpg I get. Premium near me is going for about $2.84. Just to break even on cost per mile, I would have to get 3 mpg better, or 17 mpg average for all miles. Not going to happen with my 6.0L 2500. So for me, Premium is all hat and no cattle.

I do get a performance edge using E85 at roughly 100 octane. MPG takes a hit, for sure. Roughly 11 mpg for all miles with it. But it is $1.85 a gallon near me. That equates to 16.8 cents a mile. So I can get premium power performance at substantially lower cost per mile.

I do love flex fuel engines.

[JohnWedell]

Just read the manual for the truck in my sig. it says to use 87 to 89 and recommends 89. It says not to use 91. Interesting

[smurfs_of_war]

Yes, 87-89 with no disclaimers for use in towing or other situations. One of the reasons I wanted the 6.4- they aren't picky about what we feed them.

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[jloco]

Originally Posted by Mad Cow

The gas at a name brand is the same gas at a mom and pop. It all comes from the same local fuel terminals. And that terminal fuel comes from a variety of refineries, not all the same brand. Now, different stations will have different additives fed into the stream when a tanker is loaded, but the gasoline is the same stuff. In my over 5 million miles as a commercial driver, that included some time tanking fuel. Even premium is just the same regular gasoline, but with octane boosters added when the tanker fills up at the terminal.

I am cheap. I have no problem getting fuel at a high volume no-name place to save a few cents a gallon. The key being.... high volume. High volume fuel outlets will have lower risk of fuel contamination.

Right. And it’s the additives I’m talking about and want. The Top tier stations I go to are all high volume sellers.


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[vcbice]

I've done a bit of research with gas in the past, in a lab as well as on the road.

First, lower octane fuel has the potential for more power as long as there is no knocking/pinging.

Second, running higher compression/boost with higher octane will get more performance than running lower octane.

Third, most modern engines have knock sensors and will retard your engine performance if they sense an issue.

So, yes, you can be cheap and run lower octane fuel. If you aren't running hard you won't notice much of a difference. Fuel mileage difference will be 10% or so at most. So you will get, eg, 10mpg when towing instead of 11mpg. Most won't notice that as road conditions make more of a difference.

The result is that most people will not notice a performance difference, even when the engine has 'detuned' itself. But, the engine is 'suffering' a bit.

So, I run at least the octane level specified by the mfg and if I can sense pinging (as in low alt, very hot day, nigh performance) then I will go up a grade.

And, yes, all gas comes from the same place, just additives are different. These days the injection systems can be finicky about the additives. I will spend extra to get some of them.

Last, several years ago I was on a cheap streak and decided to go all out for cheap gas. After 30k miles I saved about $100 (that is in a year) over the previous 30k miles. I stopped worrying about cheap gas. I would have saved MUCH more if I had not taken one weekend trip with the RV.