I usually drive my truck until the gas gauge tells me "0 miles left", so yesterday I pull into the gas station, a Chevron, and I'm thinking... I haven't put premium into the truck yet, I wonder what changes I'll notice...

So I fill her up to about $55 on premium gas, and take off...

WOW, the increase in engine power is like driving a totally differant truck - I almost consider it like driving a sports car.

I thought the truck was pretty fast already, but now I love it!
The only mods I have currently are a true dual magna flow exhaust system.

I can't hardly wait to add a cold air intake on it, and see how it does then!

 

You should never let the tank go below 1/4 as you start to suck up crap which clogs your fuel filter and leads to other issues. Since you have the exhaust, 93 gas and looking into the cold air intake, I would really consider the superchip to allow all the items work in conjunction with the truck.

 

Yeah... I concur on the tuner option. It's amazing how 'general' the tune is on the truck until you dial it in and see what it will really do.

 

I just started running 91 in mine (high as it goes at our altitude) and my impression was the same. A very, very noticeable appreciation in gas mileage and a very noticeable difference in power/acceleration. This is the first vehicle I've ever owned that I could tell the difference between mid-grade and high-grade.

 

Oh, and my wife used to do what you do in terms of running the fuel down. Then she learned that the pump is cooled by the fuel (in many vehicles - including ours as I understand it) and that fuel pumps are very expensive to have replaced!! That's why the indicator kicks in so early. You need a good 8 or so gallons to keep it submerged...

 

Yep The higher grade of fuel does make a difference in my '05 F150 5.4 KR. I did the microtune for premium fuel and am very happy with the results so far. I also did the Magna flow dual exhaust and K & N air filter.

That brings me to a question now. What the heck is a Vortex Valve and does it do anything to increase HP and MPG? Is it like a Tornado? Anyone know anything about this?

 

Ive always just run 87 in my 02 Do you guys really think that if I switch to 93 I will see that big of a differnece?

 

The real difference will be in your pocketbook - unless you get a tuner and have your truck's 'puter set for the best performance using 93 octane. My '01 KR 5.4L gets close to 19mpg and is stock.

 

Just an FYI before you go putting more money into your tank than need be. Switching out to a higher octane gas on a factory motor is pointless and a waste of money. You will not see any performance and or mileage gains whatsoever.

The octane rating is nothing more than a measure of how well the gas will resist detonation. In otherwords if the car isn't knocking or pinging (detonating) there is no need to increase the octane levels. Any percieved performance gains are just that percieved because you think they should be there they "appear" to be there.

Now if you have a tune that advances timming then yes you will have to run a higher octane gas dependant on what the tunner tells you, but with a factory calibrated program that is made to use 87, putting anything other than 87 into it is just pissing your money away.

 

How do you explain all the posts where people said they "couldnt believe the differnece?" Anyone else have any thoughts on this?

 

Well It is a proven fact that if the motor was made to run on 87 and the only change you make is to put 93 in it YOU WILL NOT GAIN ANY HP OR TQ.

Think about it like this. The more efficient a vehicle is the better gas mileage it gets right. Ok so the way to increase hp & tq is to basicly make the motor more efficient. In other words a motor putting out 2hp per ci. is more efficient than a motor putting out 1hp per ci. So in theory and reality in most cases it will burn less fuel to do the same ammount of work.

Now take a truck that was made to run 87. If all it took was switching to 93 to pick up 10hp and 15lb ft, in turn making the motor more efficient why wouldn't Ford suggest using 93 to begin with that way their MPG ratings would be better than they currently are?

So you guys are picking up more hp and tq by switching to 93 over the recomended 87. How much power would you say you are picking up? 10hp? 15hp? I am just curious because usually it takes a dyno to niotice anything under 10hp. SOTP you WON'T feel 5hp. Here are a few interesting reads:

http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm

http://autorepair.about.com/od/gener.../aa060504a.htm

 

Unless the computer is set up for 93 octane nothing will change. I believe we are set up for 87 octane from the factory. So anything higher is a waste. It has been discussed here many times. Do a search.

 

The guy is right, octane level determines the flash point of gasoline. Higher octanes have lower flash points. Meaning that they have to be compressed/heated more to explode. That's why, If you engine has a detonation problem, switching to high octane gas will help it.

The reason that some of these tuner's "suggest" that you use "high octane" fuel, is because they advance the spark timing, and a slower burning fuel is sometimes needed to prevent detonation. That's why if you put "high octane" fuel in a stock f-150, you're wasting your money. Cause there are no benefits. Your truck is designed to run on 87. Now if you have lots of carbon buildup (increases compression and possibly increases temps), or you advance your timing you may need to run higher octane fuel to prevent detonation.

My truck was almost 2mph slower in the 1/4 running 93 octane over 87! Go figure that!


I don't get this statement! Your truck sucks fuel from the bottom of the tank anyway! What difference does it make that the fuel is low? Also, WHO PUT CRAP IN YOUR FUEL TANK ANYWAY?

I run my truck to below "E" EVERY tank (see how far I can go) and I have never had a problem with stopped up filters, and I'm on my original fuel pump. 170,000 miles. And I leave my truck idling for days at a time, so the fuel pump has been put to the test.

 

You let your truck idle for days at a time? Can you elaborate as to why? Just curious...

 

I thought it was understood that the change over to higher octane fuel was in conjunction with making a micro tuning change. Just switching fuel grade by itself will probably not reflect any major changes in HP or MPG.