91 Octane ethanol free vs 93 Octane E10 in Hellcat

[Hellcatcfp]

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?

 

[BULL]

@Speedy!

 

[BULL]

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

: )

 

[EricG]

I have access to both, played around with 91 no-ethanol for a few tanks and went racing.

My trap speeds with 91-Shell E-10 and 91-octane no-ethanol were exactly the same. Considering the 91-no ethanol is almost $1 more per gallon I gave up on it.

My car runs great on 91-shell here at a mile high +

 

[BULL]

I have access to both, played around with 91 no-ethanol for a few tanks and went racing.

My trap speeds with 91-Shell E-10 and 91-octane no-ethanol were exactly the same. Considering the 91-no ethanol is almost $1 more per gallon I gave up on it.

My car runs great on 91-shell here at a mile high +

Useful for sure, but what I'd like to see is any changes in STK in a data log

 

[EricG]

Useful for sure, but what I'd like to see is any changes in STK in a data log

Agreed, and I would like to know if/how much knock I'm getting on 91-Shell every day.

 

[Linda's Hell Cat]

Me personally I can not be an e85 HC
I have no where close to me to get it.
I work so much I don't have time to go South and then drive North
I am also nor like the guys who want to keep up with the testing of .......is it good.
Or the maintenance that many don't post about.

I hope those that do take advantage of E85 and all it does for boost wil let everyone know what they do for the care or maintenance!

 

[Unholy707]

N

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?

o, stockchellcats are tuned in 10% ethanol from the factory.

 

[Unholy707]

. That’s why stock stoich is 13.5/6 (10% Ethanol) instead of 14.7 (0% ethanol)

 

[DavidKFla]

100 octane is what these cars really like with a stock tune. This is from my experience.

 

[Unholy707]

Because all regular pump gas has at least 10% ethanol, unless you pay a lot more for ethanol free.

 

[Unholy707]

I put 100 octane in my stock m6 for dyno day. Did it make a difference? Who knows - dynoed at 680 to the wheels bone stock. Didn’t have hp tubers, but I bet you it was running a bit lean and had to add fuel. Which is fine, the stock pcm can add/remove 35% all on its own.

 

[DavidKFla]

I put 100 octane in my stock m6 for dyno day. Did it make a difference? Who knows - dynoed at 680 to the wheels bone stock. Didn’t have hp tubers, but I bet you it was running a bit lean and had to add fuel. Which is fine, the stock pcm can add/remove 35% all on its own.

I'm going to start adding 5 gallons each time I get to the track on a drag & drive. Try and keep it at 1/4 tank before adding it.

 

[EricG]

100 octane is what these cars really like with a stock tune. This is from my experience.

I've tired using that, I believe MS109 from VP fuels in my car with the stock tune, didn't run any quicker/faster.

 

[DavidKFla]

I've tired using that, I believe MS109 from VP fuels in my car with the stock tune, didn't run any quicker/faster.

Just added it this week to a stock Durango at Drag Week. Picked up .15 with everything the same except that it had a 20-25 mph headwind that wasn't present earlier. Guy was ecstatic.

 

[EricG]

Just added it this week to a stock Durango at Drag Week. Picked up .15 with everything the same except that it had a 20-25 mph headwind that wasn't present earlier. Guy was ecstatic.

Maybe he was just running shit gas before, so it seemed to make a huge difference. Local tuners here say what pump gas you buy matters. In 35k miles I have only ever put Chevron or Shell 91 in my car and always try to stick to Shell if I can.

 

[Unholy707]

You won’t run faster, it’s just safer - no detonation with race fuel.

 

[Unholy707]

But stock tube isn’t meant for it and it could have the opposite affect. Mixing is what a lot of people do, adding a few gallons of race fuel to 91 to raise the octane a bit

 

[Unholy707]

Still not needed on a bone stock car though.

 

[DavidKFla]

Maybe he was just running shit gas before, so it seemed to make a huge difference. Local tuners here say what pump gas you buy matters. In 35k miles I have only ever put Chevron or Shell 91 in my car and always try to stick to Shell if I can.

Could be he was running crappy gas. The higher octane cuts down on detonation which allows the ecm to run a little more timing since the knock sensors aren't sounding off.

I put 91 in my Charger one time and it ran like shit while on a trip. I started topping off with 93 asap.