Shell V-Power test

[Rick Rae]

Originally Posted by Telco

Just can't bring myself to buy anything over 87 for a vehicle that doesn't require it.

Agreed. I'm only running the premium for this test because it's the sole grade with 4x detergent that Shell touts as "gunk-removing" versus "gunk-preventing." I didn't expect a performance improvement (at least, not an immediate one) since my engine shouldn't be knock-limited.

Personally, I'd tweak your statement to say "that doesn't benefit from it." If I could get better-enough gas mileage from higher octane to more than offset the additional cost, it'd effectively be less expensive, and I wouldn't hesitate to use it whether it was required or not. But that's almost semantics, as I doubt any engine that doesn't require high-octane fuel will show any significant improvement when using it.

Nope, if there's really a FE bump here I think it's from something other than the octane rating.

Rick

[Sigifrith]

I'm running a few tankfuls thru my truck along with Auto-RX. Shell is offering new credit card customers a $25 certificate if you buy $100 worth of gas in the next few months.

[n0rt0npr0]

I have tested higher-than-required octane and logged the results off-site with my 1989 Chevy v6 mpfi, and the higher (89) octane was ALWAYS cheaper to run ONLY in the winter. In the summer it always was 4% under baseline.
I'll be performing the same testing in a couple months on my 96' Monte.

IIRC - 3.5% more than 87octane, and I got an average of 5.9% more gas mileage.

Originally Posted by Rick Rae

Agreed. I'm only running the premium for this test because it's the sole grade with 4x detergent that Shell touts as "gunk-removing" versus "gunk-preventing." I didn't expect a performance improvement (at least, not an immediate one) since my engine shouldn't be knock-limited.

Personally, I'd tweak your statement to say "that doesn't benefit from it." If I could get better-enough gas mileage from higher octane to more than offset the additional cost, it'd effectively be less expensive, and I wouldn't hesitate to use it whether it was required or not. But that's almost semantics, as I doubt any engine that doesn't require high-octane fuel will show any significant improvement when using it.

Nope, if there's really a FE bump here I think it's from something other than the octane rating.

Rick

[Spule 4]

http://www.toptiergas.com/index.html

I think the additive is GLC 9424075....

http://www.youtube.com/watch?v=LD-G410gplY

[Rick Rae]

Originally Posted by n0rt0npr0

...the higher (89) octane was ALWAYS cheaper to run ONLY in the winter. IIRC - 3.5% more than 87 octane, and I got an average of 5.9% more gas mileage.

Interesting. Did you see this in any brand of gas?

Regardless: Thanks for the info!

Rick

[n0rt0npr0]

RR,

Thanks for doing the testing!
And I did not test every brand...only Shell and Marathon
My Marathon tests were done in a separate colder month but I only did three tanks worth of testing and Shell I went with 5. I also stopped in the middle to re-baseline mileage.
Oh yeah, I emergency filled with mobil one day during testing and that one tank of mid-grade mobil did better than both marathon and shell. Strange.

Also I tested this on a 1993 Geo Prism automatic with negative results. The midgrade did 5 to 9% worse on mostly highway miles (80%) While the Chevy was mainly driven city (60%) with positive results.
But glad you are testing this! I'll be taking part in this later in the year.
~Will

[Rick Rae]

Looking forward to seeing your results, Will. Thanks for sharing!

Fifth and final V-Power segment complete; 35.29MPG over 322 miles. I installed my repaired instrument cluster during this tank but used the GPSr mileage one last time. I'll run my GPSr for this tank also and check its figures against the cluster's odometer; that will give me a correction factor (if one's needed).

I decided to stay with Shell for a while but stepped down to mid-grade (89 octane) for this fill. Maybe a tank or two of that, followed by a tank or two of their regular, then returning to cut-rate gas will help pinpoint the source of the improved numbers.

Capsule summary to date, using the five prior fills as a baseline:

Random Regular: 1439 miles using 44.13 gallons yielding 32.61 MPG.
Shell V-Power: 1577 miles and 45.301 gallons yielding 34.81 MPG.

Rick

[n0rt0npr0]

Rick,

Thanks for sharing your results!

And I think you should say 33.03mpg is your P&G random regular baseline, and 35.6mpg is your V-Power p&g comparison average.

Result is an 8% increase in FE from regular unleaded to v-power higher octane fuels.

However I regularly see a 4-5% increase when I switch from random fuel brands to one strict brand. This is due to the computer not having to err so much when adjusting fuel trim and timing from the different brand formulations. Staying with the same brand allows the computer to stay in the "sweet spot" for FE (you have to do your own regional research to find out who is who in brand compositions.)

Awesome results so far! ttyl
~Will

[Rick Rae]

Originally Posted by n0rt0npr0

...I regularly see a 4-5% increase when I switch from random fuel brands to one strict brand. This is due to the computer not having to err so much when adjusting fuel trim and timing from the different brand formulations.

That's interesting, because I've read so many times that, for the most part, "it's all the same gas" and only the additives differentiate one brand from the next. Your experience implies the additives make a pretty significant change in fuel behavior. (That, and/or differing percentages of ethanol).

I wonder if this could be tested by staying with one cut-rate brand or station for a while? Might be tricky since, unlike top-tier stuff, who knows which truck filled their tanks this week. Worth a try, though!

Awesome results so far!

Thanks, though I dunno how much it's really worth, given all the variables. For example, the car's about to go into the shop for timing belt/tensioner/water pump replacement and 100K service. You just know they're gonna idle the heck out of the thing, and then there's the changes from the maintenance too. But if anyone gets something useful out of it, or it prompts someone else to try a controlled experiment, it was worthwhile.

Rick

[n0rt0npr0]

I don't know how any two refinery's could produce the same performing base gasoline's

I am implying additives and ethanol percentage produce significantly different FE, and I've been keeping a list of vehicles/engines that are driven that claim otherwise to find any sort of correlation.

I wonder if this could be tested by staying with one cut-rate brand or station for a while?

That's part of the way I solidified my belief.

You should fill your tank up right before and right after your vehicle gets repaired.
~Will