I seem to be getting way better mileage and better characteristics out of premium than the regular gasoline, like enough to save money by buying premium. Anyone else tried this?

 

I'm skeptical. Too bad you don't have the numbers to prove it.

 

I have a 2005 Lariat with the 5.43V and it runs alot better on premium and seems to get better milaage as well. I don't keep track of milage, whats the point if your going to drive trucks.

 

The only difference between regular and premium is the resistance to detonation. High performance vehicles require premium because of their increased compression. If your getting better mileage on premium, you've got a slight predetonation (pinging) problem. Could be retarded timing, among other things.

 

Octane has nothing to do with mileage and performance in a stock engine. As devino correctly points out, the ONLY thing a higher octane rating means is that it literally has more octane and less heptane, and can be compressed further before combusting on its own like a diesel engine.

When you say "better characteristics," that's purely a qualitative term. If you truly were seeing some quantitative benefit by putting premium in an engine that doesn't have high enough compression to see any difference between regular and premium, then you have a pre-existing detonation issue. Fixing that and using regular gas will save you more money (and your engine).

 

Something more
Fact or Fiction?: Premium Gasoline Delivers Premium Benefits to Your Car: Scientific American

 

I'm sorry, guess its my imagination.

 

Maybe it's that extra 30-40 cents per gallon that's causing you to tread lightly on the go pedal that's leading to some slightly better mileage?

 

You only need to tell that to your wallet! I have done the same

 

The premium gas around here reeks of ethanol. We get better mileage on regular. Although starting about a year ago most all of our vehicles won't run on regular without pinging. And the octane rating stayed the same.

 

taking my usual role as devils advocate:

it could be that his ignition is unknowingly too far advanced, thus taking advantage of the higher octane fuel.

i've known guys in the past to do this, purposely advance the base timing several degrees to gain power, and run premium fuel to stay out of detonation.

just throwin it out there..... at least he isnt claiming to get 30mpg from his 460

 

Really crappy gas leading to carbon buildup and increased compression maybe?

 

On a newer computer controlled vehicle with knock sensor, the computer will provide more ignition advance (sometimes) with premium which improves mileage and torque a bit.

Bascially the computer slowly advances timing until the knock sensor kicks in... it will advance farther with premium.

On a non computer vehicle like a dent, if it runs OK on regular, there won't be benefit with premium... unless the gas formula is different (ie less alcohol).

 

Thank you sir. I knew the 5.4 3V liked premium, just was not sure why. Thank you for explaineing it, I knew I wasn't crazy.

 

Mine has trouble starting on a cold morning with regular, it is a 10+:1 460, not a "stock dent" at 6000' elevation. With regular it starts and dies, starts and misses, with premium, it fires right off, no dying and no missing, hit the key and it its good to go. When warm, it sometimes has to crank a while to take off, from that cheap gas with e10 blend boiling and fogging out the carb. Premium doesn't do this either. And finally, my 84 honda xl600r kick start does not like anything less than 91. Your leg will wear right down at 5:00 am starting that thing on 85 octane. It won't run on it, 91 never had an issue. That motor specs to 8.5:1 comp. and it is original. I don't buy that 85 and 91 octane are the same just more resistance to pinging. I beg to differ, if I fill my bike up at those pumps that have one hose for all 3 fuel grades, I will have a well conditioned leg by the time I get new fuel, I go to one of the 3 fuel stations left in our town with seperate hoses for the fuel grades. I think when you buy only 2 gallons you probably get 1/4-1/2 gallon of the cheap stuff to purge the line, almost worth asking the guy next to you if you can pump a gallon into his car free of charge to save my right leg.

Next study I have conducted is on Husquvarna chain saws. The cheap gas leaves deposits on the plug, plugs the spark arrestor, and again, you better eat your wheaties to start those things on a cold morning in the mountains. Run premium, or even better, av gas, problems solved.