Shell V-Power test

[Rick Rae]

Could be... but the only way to find out is to try.

Rick

[Rick Rae]

Third segment complete; 35.29MPG over 318 miles. Returned to NICE-ON P&G for this tank and, as I expected, FE jumped.

For comparison, the most recent prior tank driven that way was 33.64MPG, but the pump was labeled "up to 10% ethanol." The tank before was at 34.11MPG and was also NICE-ON P&G, but it included a lot of mountain and foothills driving.

So even though this tank is a new "personal best" (60% over EPA, go me! ), it's arguably in line based on the earlier numbers (especially if we assume my driving skills have continued to improve.)

Two more V-Power tanks to go, then I'll drop back to the cut-rate stuff.

Rick

[Rick Rae]

Fourth segment complete; 36.24MPG over 305 miles. At this point I have to cautiously admit V-Power (or Shell in general) might be helping, as there's been a definite upward trend over the last few tanks.

Know variables, in order of likelihood as regards better mileage:

• I returned to NICE-ON P&G last tank.
• My hypermiling skills continue to improve (I hope! )
• The weather hasn't been as insanely hot over the last few tanks
• Last two tanks have used GPSr mileage while my instrument cluster is being repaired

The last point is a total wild card, since I've never bothered to check odometer calibration. The VW's speedo is known to read a little high, but if that's reflected in the odometer the GPSr mileage readings would be lower if anything. My repaired cluster is expected back today or tomorrow, so I'll have an answer on this point fairly soon.

The fact that I stopped using P&G around the same time I started the V-Power test and kept about the same numbers -- and FE jumped when I started P&Ging again -- certainly implies I'm getting more miles per gallon on the Shell stuff. If that's indeed true, I can think of a few explanations. In what I think is decreasing order of probability:

• The lower octanes are E10 but V-Power contains no ethanol
• The "slippery stuff" Shell adds to their fuels reduces engine friction
• V-Power really is usefully cleaning my engine
• My engine is taking advantage of the higher octane

I read the bit about E10 in a discussion somewhere, but I haven't confirmed it yet. If it's true and the cause of better gas mileage, then dropping to mid-grade Shell should cause my numbers to drop. (But, does anyone add ethanol to their Summer blends, or is that just a Winter thing?)

"Slippery gas" is a Shell claim I recently heard. Supposedly they include additives to reduce friction. If this is the only factor, then dropping to regular Shell should keep my numbers up and returning to cut-rate gas should cause them to drop.

The engine-cleaning thing, if true, should result in my numbers staying up even after returning to el-cheapo gas.

If it's a knock-limiting issue, then one of mid-grade or regular Shell should drop my numbers, but they should go back up if I use anyone else's mid-grade or premium.

I'm currently on the fifth and what was supposed to be the final tank of Shell. But depending on how the numbers go I may stay with Shell a while longer to see if I can gather more information. It'd be nice for this to yield a hypothesis as to what effect V-Power (or Shell in general) had (if any), so others can run actual controlled experiments.

Rick

[Bill in Houston]

Originally Posted by Rick Rae

I read the bit about E10 in a discussion somewhere, but I haven't confirmed it yet. If it's true and the cause of better gas mileage, then dropping to mid-grade Shell should cause my numbers to drop. (But, does anyone add ethanol to their Summer blends, or is that just a Winter thing?)

Depending where you are, there can definitely be ethanol in Summer blends.