You won't the only reason for higher octane gas is to keep predetonation from occuring in higher compression engines.

 

That is pretty much what I thought. Then why would you want to program you D for higher octane? It seems like it would cost you more at the pump and not get you anything?

 

When you set the hypertech to run 93,it gives you more power, has a more agressive timming curve. If you select 93 while having 87 octane, your engine will ping. They are nice if you have minor mods but if you have more than just cold air intake/exhaust, the extra $139 to have a custom flash is better. I should be able to reprogram dodge ecu's by next year, and hopefully dyno tune them as well.

 

D911 - The Hypertune information says that performance at 87 and at 93 with their programing is the same.

 

Where does it say that? Premium tune gives you +11hp/+18tq and 87 tune gives you +7hp/+11tq. I owned a hypertech for my durango for2+ years, just sold it a few weeks ago.

http://www.hypertech-inc.com/get_dyn...025&tp=pdf

 

D911:

I have not studied the manual to check that, so I refer back to that post above yours.

 

Like I said, minimal difference. I don't know anyone who can feel 4hp or 6ft.lbs. of tq difference. I can however see 87oct = $2.99 per gal verses 91oct.=$3.19 per gal+ some booster to get the other 2 oct.The slight difference is achieved by advancing the timing, thus creating the need for higher octane. Another factor is compression ratio. When I sold Corvettes for a living in the late '90s we only filled 'em with 92 oct. fuel. Reason is the vette's compression ratio of 9.5-1, as the Camaros were filled with 87 oct because their comp. ratio was only 8.5-1.Another example is alot of guys get aluminium heads which raises the comp ratio about 1 point allowing for advancement of the timing and requiring higher octane fuel and rewarding you with more power.

 

Welp, I am finished with my 2nd tank running 87 octane. I do not feel hardly any difference in power between 87 and 93. At least not aware of it for day to day regular driving. Gas mileage is still good, almost 1 mpg better than stock. But either 87 or 93 setting, you can definitely feel the responsiveness difference when comparing to stock setting. I love this hyper tech setting so far.

I mainly bought this hypertech so I can drop my premium fuel requirement to regular fuel and give me slightly better MPG. This this will save me several bucks per tank and will pay off the hypertech programmer less than a year. So far,my D runs much better with regular fuel and hypertech 87 setting vs the OEM 91 octane setting.

I bet this would be a great product to use to replace the OEM setting for those D owners that may have gotten that death flash from the dealership to address the pinging issues!