91 Octane ethanol free vs 93 Octane E10 in Hellcat

[DavidKFla]

Jon and Dave,
In my case the car runs just fine on Amoco 93 at $4.19 a gullup. Da 104 and upurds duz nuthin butt cause problemz. Cum 2 find out. Dis GD patrolum station down da street frum da track. Waz sellan 104 leaded free BUT da gas waz leaded. I am lucky I didn't throw a piss tun or a knock and a lifturd go thru da hood. Needless 2 say, it did alot of damage.

There's bunch of 110 leaded race gas available from regular gas pumps around here. You have to be careful.

 

[zhc]

Saw something stating stock Hellcats are tuned at 91 Octane (0% ethanol)?

I have the ability to purchase 91 Octane 0% ethanol or 93 Octane E10. Thoughts on this?

Unless you have other factors at play like bad fuel, higher octane is going to knock less regardless of ethanol %. You could still run 91 in a Hellcat but it'll usually knock some more and pull more timing to reduce or eliminate it. Although that sounds bad, how bad can Dodge's octane/knock management strategy be when there's a warranty to back it up?

 

[DavidKFla]

Unless you have other factors at play like bad fuel, higher octane is going to knock less regardless of ethanol %. You could still run 91 in a Hellcat but it'll usually knock some more and pull more timing to reduce or eliminate it. Although that sounds bad, how bad can Dodge's octane/knock management strategy be when there's a warranty to back it up?

What if there is no warranty?

 

[zhc]

What if there is no warranty?

That would be a tangent away from the point I was trying to make. The OEM has way more data and testing than any of us would have access to and that data tells them that they have everything setup to be reliable on 91, stock, unmodified.

Given a choice however, I'd still run 93, higher if racing but staying unleaded and avoiding mtbe as it doesn't need a whole lot more to clean up any knock that it might have on 93 on a stock tune.

 

[DavidKFla]

That would be a tangent away from the point I was trying to make. The OEM has way more data and testing than any of us would have access to and that data tells them that they have everything setup to be reliable on 91, stock, unmodified.

Given a choice however, I'd still run 93, higher if racing but staying unleaded and avoiding mtbe as it doesn't need a whole lot more to clean up any knock that it might have on 93 on a stock tune.

I understood it to say that since you have a warranty, don't worry about it. I must of misread.

I think that the acceptance of 91 is simply because 93 isn't available in all parts of the country and the code has been written as such.

If you look at an order form of a new one, which is no longer available, you'll see that they all come tuned to California emissions.

The use of higher octane race gas at the track is the basis of my statement. Better protection and performance in my mind.

You are a top notch tuner and have far more experience than I do. I learned to listen to my tuner the hard way!! 🤣🤣🤣

 

[zhc]

The use of higher octane race gas at the track is the basis of my statement. Better protection and performance in my mind.

100% agree!

 

[BULL]

I bet most people can't see, feel, or tell an occasional 1/4 or 1/2 point of STK, but your motor can, so my point was that a data log would reveal this and then you could make a valid determination between the two.

Further, while on face value, 91 vs 93/E10 is an obvious choice, I bet the reality of one vs the other isn't.

And then even further further , one batch of fuel to the next might have differences.

.02

 

[DavidKFla]

I bet most people can't see, feel, or tell an occasional 1/4 or 1/2 point of STK, but your motor can, so my point was that a data log would reveal this and then you could make a valid determination between the two.

Further, while on face value, 91 vs 93/E10 is an obvious choice, I bet the reality of one vs the other isn't.

And then even further further , one batch of fuel to the next might have differences.

.02

The addition of 100 VP race gas helps even that out in my opinion.

I can tell the difference on 87 in the Tundra. Lower quality gas lowers mpg and power.

 

[1971demon]

What would answer this definitively would be to get you set up with data logging and do some science!

: )

There you go again with the "S" word...

 

[BULL]

The addition of 100 VP race gas helps even that out in my opinion.

I can tell the difference on 87 in the Tundra. Lower quality gas lowers mpg and power.

Sure, at the track, I'm going to run 100octane or better, but this is about DD and knowing what's better, or possibly doesn't make a difference, then making the economical choice if it's all the same.

 

[1971demon]

Any gals in dis science class?

a couple cross their legs in a peculiar fashion I would guess

 

[Hellcatcfp]

Sure, at the track, I'm going to run 100octane or better, but this is about DD and knowing what's better, or possibly doesn't make a difference, then making the economical choice if it's all the same.

I'm open to testing this in a daily setting. What do I have to buy to log?

 

[DavidKFla]

Sure, at the track, I'm going to run 100octane or better, but this is about DD and knowing what's better, or possibly doesn't make a difference, then making the economical choice if it's all the same.

Someone posted above about running 91, in a redeye, at the track.

 

[DavidKFla]

I'm open to testing this in a daily setting. What do I have to buy to log?

How do you drive?

 

[BULL]

I'm open to testing this in a daily setting. What do I have to buy to log?

Well now, that's a whole other argument!

 

[DavidKFla]

I'm open to testing this in a daily setting. What do I have to buy to log?

I'm very particular about what gas I put in the Charger. Basically Shell and BP seems to be its favorite ones. ExxonMobil is a distant 3rd.

 

[Hellcatcfp]

How do you drive?

Depends on if I take the long way to work. Though, I'm not doing pulls to 150+ if that is what you are referring to?

 

[DavidKFla]

Depends on if I take the long way to work. Though, I'm not doing pulls to 150+ if that is what you are referring to?

I call it spirited or normal driving...

😎😎

 

[Hellcatcfp]

Maybe meaningful testing requires that kind of driving?

 

[Hellcatcfp]

I call it spirited or normal driving...

😎😎

Usually a mixture of both as I have my areas along the way to punch it.