What octane are we using?

[Jako]

Here the difference between 87 and 89 is 70 cents. Not worth it to me unless I’m towing over 5000 lbs.

Quick review of last few month's records indicate 18 to 30 cents doing a blend as in post #97. A good per cent of fill ups are at a NJ Costco. I have noticed the 93 octane at Costco has been going higher in relation to 87 recently. Costco blending of 1/3 93 octane and 2/3 87 octane is about 50 cents saving over 89 at the local gas station. NY taxes are slightly higher than NJ.

 

[6of36]

Here the difference between 87 and 89 is 70 cents. Not worth it to me unless I’m towing over 5000 lbs.

I just checked gas buddy for local stations, and the difference is 30 to 50 cents higher for mid grade, and 60 cents to a dollar higher than regular for premium. Crazy wide range.

 

[Nascar Tommy]

I worked for a government agency years ago(Please don't hold that against me!) and I purchased fuel. Twice a year I would drop off fuel samples to be tested for 0ctane rating per contract. The lab people where fuel was tested were quite nice and gave me a tour.
The (R+M)/2 method basically consisted of a tricked out 1 cylinder motor with variable timing and a guy listening for the knock or no knock leaving the rating up to human judgement.
What I'm trying to say is octane is never exact.

 

[swing4terps]

Here the difference between 87 and 89 is 70 cents. Not worth it to me unless I’m towing over 5000 lbs.

Yea, here at Wawa in Mid Atlantic 89 is usually 30-40 cents more than 87. Then only another 10 cents to 91. I have been mixing 87 and 91 lately to save ~15-20 per gallon. I'd love to understand why it's priced that way. It is only a minor inconvenience, for now.

 

[Dewey]

Just watched this on Motor Trend Channel and found the results very interesting.

E85 for the win. Too bad we can’t use it.

 

[theblet]

Just watched this on Motor Trend Channel and found the results very interesting.

E85 for the win. Too bad we can’t use it.

I miss that show. New episodes havent recorded on motortrend channel in awhile.

 

[HSKR R/T]

Problem with that video, temperature controlled environment with good cooling and good airflow. In a street car, you can safely run higher timing with higher octane fuel without detonation. Even in a heat soaked engine. there's a reason there are vehicles that are high HP dyno queens that can never make a full pass at the drag strip without issues.

Just watched this on Motor Trend Channel and found the results very interesting.

E85 for the win. Too bad we can’t use it.

 

[Mr.Grid]

E85 makes great hp for a cheap price. The problem is the time of year and location you purchase from. Here in the Midwest in March, E85 at the pump is in the low E70 range because it is harder to ignite in cold weather. That blend won’t be back to E85 until the early summer months. Many I know that use E85 for racing will purchase it from a distributor when needed early in the season so they know the blend is correct. They also test it at the pump prior to purchasing to know they are getting E85. A test kit is easy to use and not expensive.

Methanol is strictly race fuel and many like myself use it (14.5 - 1 sbc). Unlike those that use a carb for methanol, I use EFI with methanol that allows for better tuning options controlled with an ECU.

The Engine Masters test is with a LS3 that is EFI (mpfi) that they can easily change/ control AFR and timing using an ECU. The last test using methanol is with a carb. I can only assume they replaced the intake manifold for this EFI to carb conversion.

A more fair test for methanol would have had them removing the fuel rails and replacing the injectors from the prior test with ones twice as large and correcting the ECU fuel map for methanol.

 

[HSKR R/T]

E85 makes great hp for a cheap price. The problem is the time of year and location you purchase from. Here in the Midwest in March, E85 at the pump is in the low E70 range because it is harder to ignite in cold weather. That blend won’t be back to E85 until the early summer months. Many I know that use E85 for racing will purchase it from a distributor when needed early in the season so they know the blend is correct. They also test it at the pump prior to purchasing to know they are getting E85. A test kit is easy to use and not expensive.

Methanol is strictly race fuel and many like myself use it (14.5 - 1 sbc). Unlike those that use a carb for methanol, I use EFI with methanol that allows for better tuning options controlled with an ECU.

The Engine Masters test is with a LS3 that is EFI (mpfi) that they can easily change/ control AFR and timing using an ECU. The last test using methanol is with a carb. I can only assume they replaced the intake manifold for this EFI to carb conversion.

A more fair test for methanol would have had them removing the fuel rails and replacing the injectors from the prior test with ones twice as large and correcting the ECU fuel map for methanol.

If your E85 tune is so close to the ragged edge that you can't run E70, you need a new tuner. It's like the difference between 92 and 93 octane. And most guys I know running E85 have a flex fuel system that will adjust the tune for the ethanol content.

 

[theblet]

can hemi's run e85 now? I know mine cant

 

[HSKR R/T]

can hemi's run e85 now? I know mine cant

With the right tune and larger injectors they can.

 

[Mr.Grid]

If your E85 tune is so close to the ragged edge that you can't run E70, you need a new tuner. It's like the difference between 92 and 93 octane. And most guys I know running E85 have a flex fuel system that will adjust the tune for the ethanol content.

Agreed….Flex fuel street vehicles will run E10 or less to E85 without any problem. The ECU mapping/ control corrects for any blend from low to high.

In drag racing competition where fastest or most consistent is the goal, any difference in ethanol blend percentage from desired E85 can possibly be noticeable. Most I know racing with E85 (and they are all using carbs) and purchasing at the pump, will test prior.

Like was stated in the video, oxygenated fuel made the most HP.

 

[Dewey]

I ran a lot of E85 in my Silverado’s when I found it for a decent price. For sure could tell there was a bit more HP. Gas mileage sucked as expected with a 3-4 mpg drop.

 

[theblet]

With the right tune and larger injectors they can.

Cool. I didn't know if it had the right seals. I heard E85 can eat them up if not made for it.

 

[HSKR R/T]

Agreed….Flex fuel street vehicles will run E10 or less to E85 without any problem. The ECU mapping/ control corrects for any blend from low to high.

In drag racing competition where fastest or most consistent is the goal, any difference in ethanol blend percentage from desired E85 can possibly be noticeable. Most I know racing with E85 (and they are all using carbs) and purchasing at the pump, will test prior.

Like was stated in the video, oxygenated fuel made the most HP.

We obviously hang out with different drag racing crowds. Yes, consistency is the goal, but unless you are changing fuel between runs, consistency shouldn't be an issue during a bracket race. And most the guys I know do fuel injection because it is easier to tune for higher HP and consistency since it will automatically adjust based on ethanol content. Of course the real serious guys also buy E85 from a fuel vendor by the barrel and not from the pump, when they want consistent ethanol content, so they aren't worried about having to test.

 

[HSKR R/T]

Cool. I didn't know if it had the right seals. I heard E85 can eat them up if not made for it.

Pretty much any vehicle made since the early 2000s is safe to switch to E85 with out a need to replace anything other than injectors and maybe a fuel pump for higher volume.

 

[BowDown]

Agreed….Flex fuel street vehicles will run E10 or less to E85 without any problem. The ECU mapping/ control corrects for any blend from low to high.

In drag racing competition where fastest or most consistent is the goal, any difference in ethanol blend percentage from desired E85 can possibly be noticeable. Most I know racing with E85 (and they are all using carbs) and purchasing at the pump, will test prior.

Like was stated in the video, oxygenated fuel made the most HP.

Most serious E85 racers I know don't use pump E85, they use ignite E85 so the content question isn't an issue.
I use E85 but the tune is closer to an e65-70 tune due to the inconsistency of E85.
Most of those same people also use an NGuage to switch maps so they can drive home after burning through a tank of ignite.

E85 in a street car not built with taking advantage of E85 in mind doesn't really yield much anyway.
My car only picked up 20 wheel hp switching to e85, my dynamic compression is about 9.1. you need to be in the 9.6 to 10s and above for E85 to be if any real benefits E85 helps with BMEP which is what causes knock.
The expense of E85 on a 10-11 SCR engine is not worth the gains IMO.
I'm moving to ID 1000's just to get the duty cycle down on an e tune and thats $1200 alone

 

[rammin03]

Wow, this thread went from a simple poll question to deep racing education and rope-a-dope extra information...

 

[BowDown]

Wow, this thread went from a simple poll question to deep racing education and rope-a-dope extra information...

Not really, if you learn and understand the concepts, all that information directly transfers to the octane question and more specifically, why.

 

[rammin03]

Not really, if you learn and understand the concepts, all that information directly transfers to the octane question and more specifically, why.

I beg to differ, it was a simple question, "What octane are you using? Not why, not because I race, no explanation needed. Just saying it hard to find direct answers in these threads when PM's or DM's should be used instead of an open dialog high jacking a thread and not even addressing the thread starter. Either way, "unwatched".