So I took my 1996 Ford F150 XLT to the muffler shop as I have noticed a lack of power and bad mpg. I was thinking the CAT was bad. He put it up on the lift, listened to the CAT then the muffler and diagnosed the muffler was bad. He then showed me how the muffler was warped and falling apart on the inside. The truck has a V8 5.8l 351 windsor in it. The salesman was telling me that I should put premium gasoline in the truck. He says that I will get the full potential of the truck power wise, and it will clean the engine. Not sure if this is correct and was trying to get other peoples opinions on the subject. Any information at all would help a lot.
Thanks.

 

I really doubt any noticable difference will come from premium gas

 

If it's MAF then you will get better performance and better mileage on premium gas. The computer can advance the timing a lot more before it starts to 'ping' so you get better performance. The premium gas usually has better detergents in it as well, so it will clean the valves and injectors. I usually run a tank or two of premium ever 6 to 8 months.

 

ummmm no. premium will get you no gains on any car unless the compression ratio and or forced induction calls for it. if anything it will get you worse gas mileage than regular since the octane is much higher your stock ignition will not get the full explosion out of the air fuel mixture compared to using regular gas.

its a HUDGE misconception that premium is better gas given its name but its not all it is is a higher octane number which means that it is harder to ignite than normal gas and should not be used an anything but high compression ratio cars that raise the temp of the air fuel mix and need the higher octain rating to prevent abnormal combustion (knock and ping)

is has the same additives as any normal gas does.

 

So does this mean that I need to put it in all the time to get better performance and mileage?

 

what mods do you have done to your truck? as far as the motor goes?

 

K&N Aircharger, basically thats it.

 

With out internal motor mods I doubt you would see any significant difference. Now if you had higher compression And a power adder (turbo/supercharger) the. It would help prevent pinging if you advanced the timing.

But to run a tank of premium through once in a while can help clean out the motor tho

 

And At 11mpg im just too damn. Cheap to put it in my truck lol

 

The "Premium" term in fuel is a marketing gimmick. Look at the RON # and look up what your engine requires for fuel. If ford claims the truck requires 87 octane, anything higher will actually hurt the performance/efficiency of the engine as a higher octane fuel is harder to burn (preignition resistant).

Most fuel suppliers do not change the detergent formulation between fuel grades, so running a tank of premium fuel every so often is just cleaning out your wallet and nothing more. If you want to clean your fuel system, use a can of sea foam in a tank of fuel every so often. Gasoline is already a solvent, an additional concentrated solvent such as sea foam will just help that much more.

 

Was that right after you installed the K&N perhaps? In general oiled filters of any type are a no-no on a vehicle with a mass air sensor.. the oil contaminates the sensor, and worse yet is an open conical type filter connected directly to the meter, distortions of the airflow at the sensor element leads to poor performance and milage. These filters should always be spaced away from the sensor with at least a 1 foot section of tubing and should also be shielded from fanwash and hot under hood air, or in otherwords in a box that is ducted to the outside like the stock airbox.


Several EFI design elements are necessary for this to be true. The computer has to be advanced enough to allow programing for both ignition advance and retard.. which didn't happen until OBD-2, the computer must also have full control over the ignition system, meaning no distributor, and the system must have some way of detecting pre-ignition and/or a misfire, knock sensor and/or crank sensor. This '96 truck has most of that but I still can't say for certainty that it would take advantage of higher octane fuel like the next generation of engines, it's still a low compression motor in the big scheme of things so if there were gains I think they would be minimal and probably not worth the extra cost.

 

18436572 is correct in saying a higher octane fuel will not improve performance or mpg. Some owner manuals also state using a higher octane fuel will actually reduce performance and it is not recommended.
Premium or higher octane gas is for an engine that needs it due to having a higher compression ratio.
Sounds like the guy who installed your muffler should stick to giving advice about mufflers !

 

A few years back in Washington State only the mid and premium grades of Chevron gas had Techron, not the 87. Not sure if this is still the case or not.

merhlin

 

No, it wasnt after the K&N Air Charger was installed. It has been recently

 

Probably a ploy to make more money. Happens here in D.C. frequently as nearly all the fuel stations are owned by the same company. Crooked people doing crooked things.