I have a 2005 F150 Screw, 5.4L, all stock. What I'd like to know is why do people get custom tunes written for higher octane fuel when this engine doesn't have a high enough compression ratio to warrant the higher octane fuel? There is no performance benefit from using higher octane fuels. Higher octane fuels simply resist pre-detonation in higher compression engines. There is no additional energy released in higher octane fuels so if the C/R isn't changed why use the higher octane?

Someone please give me a reasonable explanation. I'm thinking about getting some custom tunes, but I don't want to waste my money on something that isn't reasonable.

 

High octane + Advanced Spark = More Power

 

If you talk to a custom tuner they will be able to explain all this. Im under the impression that most vehicles run better on 87 because of the way they are programmed from the factory but custom tunes changes everything (timing advance and spark stuff-yeah you can tell im a mechanic huh ) and if done right is better to run on higher octane

 

Talk to Troyer. I ran high octane in my 2007 Screw. Better economy - enough to pay for additional fuel cost per gallon - that's it - and certainly more get-up-and-go. The high octane only is worth it if you tune.

 

x2

 

Then run E-85...has a 105 octane...

 

E85 is a bit different that unleaded

 

I guess the extra spark advance makes some sense as to why a higher octane fuel could be used...I'd still like a more detailed response...anyone?

 

Call Troyer you wont be sorry and have your credit card ready The 05 factory tune sucks.

 

Honestly give Troyer a call as he can probably answer better than anybody here unless he himself happens to read this and post an answer

http://www.troyerperformance.com/cgi...&link=mainpage

 

If I used my credit card for that I'd have to find a new mode of transportation...it's hard to drive with broken fingers!

 

07 stock tunes suck pretty bad also. My wifes 03 Expy was way faster until I did the Xcal3. Still waiting and checking email daily for the custom Troyer tunes.

 

Ahh you must be married, you have to be a man and get a seperate account that the wife doesnt know about. What the wife cant see cant hurt her, like a tune. My wife just found out about my Harley grill after 2.5 years because she found the stock grill in my basement.

 

I have seperate account, but doesn't do any good when wife is home and accepts shipment.

 

Ship to your job, friends house, relatives house. Open up a ups store account and they will recieve packages for you.