I have used Phillips 66 pure gas for my last few fill-ups and my average mpg has gone up over a mile per gallon. I have always used Costco or Kangaroo gas and averaged around 16 mpg. A while back, I started getting valve clatter so I bumped up to 89 octane. Still had clatter so I tried a few tanks of 93 octane. The clatter stayed and average mpg stayed the same. All the while, I used Costco or Kangaroo.

I switched to Phillips 66 a few weeks back. Their gas does not contain ethanol and they also advertise cleaning detergents in their gas. For my first two tanks, my average was in the upper 16's and today my average was 17.5. I haven't seen a 17 mpg average since my jeep was all stock with factory tires. For the record, I filled up at the same station and parked in the same spot all three times. And I always hand calculate my mileage. I also haven't heard any clatter in the past week either.

So is it the gas, detergent or a combination of both that had the biggest impact on the increase?

One last thing, what are the long term effects of using gas with 10% ethanol?

 

The detergent reduced the clatter after a few tanks and the more effecient fuel, read no corn oil, definitely gave you more MPG .......AND P O W E R !!!!!

Long term effects of corn oil, garbaged system, higher CO2 outputs, less power, higher carbon buildup on rings, valves, etc. plus the oil gets dirtier faster. Stay away from corn oil as much as you can afford.

 

Wow so who else besides Phillips 66 doesn't put Ethanol in their tanks. I don't think we have a Phillips 66 here.

Nevermind I just found out Florida requires the use of 10% ethanol. Sorry seals and mileage. Al Gore thinks its better this way.

 

i would say it is the water

 

Something to note: When I worked for an oil pipeline, many different gas vendors came to our "truck rack" for filling their tankers. Each vendor had their own separate tank for additives that they put in the gas tanker. Not all vendors came to this rack, but quite a number.