Unless your truck has performance mods that require a higher octane fuel or is out of tune you won’t see any benefit running higher than 87 octane in the 3.7 or 4.7. As for which filling station, it doesn’t matter. All the fuel in you area is most likely the same fuel from the same refinery. Shell, QT or whatever company will just add their “special” additive to their loads so they can tell you their fuel is better. It’s just marketing. I’ve found I get about 1 mpg worse in my 4.7 jeep running ethanol based fuel. Don’t worry too much over mom and pop stations. They are not adding water to their fuel. You truck would not run if they added enough water to their fuel to make it profitable. Some stations tend to get condensation in their tanks at certain times a year, but I’ve had that happen at Shell and Mobile stations as well.

 

Forgot to mention its a 4WD Quad.

Also wanted to add I get about 15.5 pulling a 16' deep V fishing boat. If I rember rite my user manual also recomended to use 87 octane, only thing I seen that recomends higher octain fuel so far is the Hemi last I checked dodge was too cheap to do the engineering to put a hemi in a dakota.

/drools over that thought...

 

I have the HO and according to Dodge it Premium. 91 oct. Reg for other engines. The 4.7 HO and the 5.7 both at 91

 

DonG is right. Gas is all the same . The diff is the amount of detergent each brand has. Detergent is added to the fuel during the tanktruck loading. More for Shell, less when Shell sells a load to mom & pop. So, when you buy mom & pop's you just have to use fuel injector cleaner in closer intervals. Gas is a free float commodity, If you boycott one brand, they just sell their surplus to the brands who are getting the business from the one being boycotted. Gas is gas. Choose your octane and price shop.

 

For any one that thinks running Premium fuel in a engine designed for Regular fuel, read the following:

Fuel octane requirements for gasoline engines vary with the compression ratio of the engine; diesel cetane requirements also vary with the compression ratio. Engine compression ratio is the relative volume of a cylinder from the bottom most position of the piston's stroke to the top most position of the piston's stroke. The higher an engine's compression ratio, the greater the amount of heat generated in the cylinder during the compression stroke.

Posted octane numbers on gasoline pumps are a result of testing fuel performance under laboratory and actual operating conditions. The higher the octane rating on fuel the less volatile (evaporative qualities) and the slower the fuel burns. Higher octane fuel contains more POTENTIAL energy but requires the higher heat generated by higher compression ratio engines to properly condition the fuel to RELEASE that higher potential energy. In the refining process, fewer gallons of higher octane fuels are yielded from a barrel of raw crude.

If fuel octane is too low for a given compression ratio, the fuel prematurely and spontaneously ignites too early and the fuel charge EXPLODES rather than BURNS resulting in incomplete combustion. The net effect is a loss in power and possible engine damage. The operator hears an audible "knock" or "ping", referred to as detonation. Detonation may vary from a faint noise on light acceleration to a constant, deep hammering noise while driving at a constant speed. Improper timing adjustments, vacuum leaks, or excessively lean fuel mixtures may also cause detonation.

Many vehicle owners believe that higher octane fuels are better for their vehicles since they are labeled "PREMIUM." The logic is that since it is a premium fuel it must be better. In reality, the premium label originates from the higher cost to refine and the resultant higher retail cost. Some refiners label their high octane fuels "SUPER." Some owners think that these fuels will make their vehicles more powerful. Only engines with high compression ratios can deliver all the potential energy from higher octane fuels! Always consult the manufacturer's octane recommendation to determine the proper octane requirements for any given vehicle. Generally, engines with compression ratios of 9.3 : 1 or less will safely operate with unleaded 87 octane fuel. Engines with higher compression ratios usually require higher octane fuels.

Many owners who operate vehicles designed to operate on 87 octane fuel experience ping and knock. They usually "fix" this problem by purchasing the higher priced, higher octane fuels. Most owner's manuals indicate that some light and intermittent ping is normal but that heavy or sustained ping or knock should be attended to by either purchasing the correct octane fuel or servicing the engine.

Most fuel refiners blend fuels for geographic areas and adjust their blends seasonally. These blending techniques compensate for the decrease in oxygen content with an increase in altitude and compensate for volatility during the warmer or cooler seasons. Significant ambient temperature changes (40 degrees Fahrenheit) or altitude changes (4,000 feet) may cause some serious engine detonation. This problem is usually corrected by filling the tank with "local" fuel that has been properly blended for season and altitude.

So unless you altered the compression ration of your engine it doesn't matter what you did to the intake, exhaust, or computer management system. Botttom line its your money.

 

Is it a myth then that high octain fule is a more efficent at cleaning (ex:Injectors)?

I always thought that injector treatment increased the octain level of the fuel.

 

It is a myth. The refiner puts the same amount of detergent in all octane levels. As for injector cleaners, they are just concentrated detergent cleaners and don't boost the octane.