hows it goin guys/gals. i just bought me an 04 f150 fx4 nbs. 5.4 3v, automatic, 4x4, etc. i am looking at getting an xcal 3 with vmp tunes. now... i was looking through the tune options and thinking of the 89 octane tow tune, 89 performance tune and the 89 gas mileage tune. but i wanted to ask for opinions on the mileage tune, how much better mileage does it give over the tow tune roughly? it would only be used on hwy trips but if its nothing special than i'll just get the 91 performance tune instead just to have.

truck is stock other than true dual straights and no crossover and still has stock cats. it'll get a magnaflow di/do muffler for inspection purposes.

 

Just a little curious why you are going to use 89 octane with the present fuel prices. There is not much difference between 87 and 89 if your tuner is proficent in his abilities.

 

might as well opt for the 91 octane if it's available in your area

 

Go with the 91 performance....

 

Well let the flames begin to burn my rear, but I doubt that there is one person on this board that can "feel" the difference that a 91 octane tune makes over an 87, or even an 89 octane performance tune. The minimal gain in HP just can not be felt. It has become relative to a placebo. Not on a n/a engine do you need it anymore.

 

I noticed a big difference when I tuned for 91. I advanced the timing & ran 91, truck picked up et & speed in the quarter. I was afraid to advance much over the canned 87 tune running 87. Seat of the pants you probably don't feel it but time slips show it.

 

because i dont like the cheap gas and i've always used 89 as long as it was available.

its available here.

thanks guys. this is why i asked before making my final decision. i'll get the 89 tow and perf and the 91 perf.

 

Let me clue you in to something - when you buy gas labeled as 87 and it's 10% ethanol, it's really 89 unless they are adding ethanol to 85 octane gas. I'm not aware of any 85 octane gas available anywhere except in high altitude areas such as Colorado.