Towing with a 91/93 Octane Tune? Worth it?

[Jacoby]

2 hours ago, TexasGMCZ71 said:

what fuel program are you using to run this mix with?  E85 is hard to find around her but its possible.  If it was same MPGs when towing I could see it being worthwhile.

If I can decipher what he said then he is using a 93 octane tune with a programmer and just running a mix of E85.  Again the E85 is doing nothing for his truck power wise.  It will run just as good on 93 as it would mixing it with E. 

 

You're truck has to be Flex Fuel capable for you to see any power benefit from E85

[Ezekiel2517]

I dont have enought knowledge to argue it either way.  I beleive e85 has a higher effective octane rating than even 93. However it has less inherent energy than regular gas.  If the 93 tune cannot take advantage of anything higher than 93 then it seems like you would suffer in performance. 
 

However I dont fully understand why the stock flex fuel trucks bump up HP by about 30 horses just by running E85.  What inherently makes it able to do that if not for adjusting timings and whatnot to take advantage of higher octane?  And if the stock truck is smart enough to do that then why can the stock truck adjust to optimize for 93? 

 

 

[CamGTP]

It's a combination of more timing,  air fuel ratio difference and the fact that E85 will cool the intake charge more than the regular pump fuel. It has a better ability at removing heat and create more power.

 

This article should help with a few things.

 

http://www.superchevy.com/how-to/additional-tech/1110chp-e85-fuel-switch/

[Jacoby]

5 hours ago, TexasGMCZ71 said:

I dont have enought knowledge to argue it either way.  I beleive e85 has a higher effective octane rating than even 93. However it has less inherent energy than regular gas.  If the 93 tune cannot take advantage of anything higher than 93 then it seems like you would suffer in performance. 
 

However I dont fully understand why the stock flex fuel trucks bump up HP by about 30 horses just by running E85.  What inherently makes it able to do that if not for adjusting timings and whatnot to take advantage of higher octane?  And if the stock truck is smart enough to do that then why can the stock truck adjust to optimize for 93? 

 

 

It’s because on flex fuel vehicles there is a sensor that reads the alcohol content. As the alcohol goes up the computer is able to adjust its tune ( usually increasing timing and adjusting are) therefor that’s where the increased power comes from. On non flex fuel vehicles the map is optimized for a particular octane. On a 6.2 it’s 93 on a 5.3 it’s 87. The ecu can’t adjust for higher octane therefore running E in a non flex fuel vehicle is a waste.