OK, after over a month of experimenting, I pretty much can draw a conclusion regarding my MPG experiment, driving my vehicle on 87, 90 and 93 octanes. It would appear that using 93 octane gives 17.6 MPG around Pittsburgh while 87 octane gives 16.6 MPG. a 6% difference.

Of interest is that at least around here, 93 octane gas is the same 30 cents per gallon more than 87 octane as it was a few years ago at half the price. Meaning that it's $4.30 per gallon versus $4.00 per gallon or 7.5% more for 93 octane. Yet it used to be 30 cents/gallon more but the differential was 15 to 20% (back when regular gas was at $1.50 to $2.00 and premium was $1.80 to $2.30).

So my bottom line conclusion, surprisingly, is that at today's prices it doesn't make sense to "cheap out", although it did when gas was under $2. Both 87 and 93 octane gas costs about the same cents per mile now.

So, I am surprised but the numbers don't lie. Although I suspect that premium gas will eventually rise to 15-20% more than regular, as opposed to the current "bargain" in relative terms.

 

Thanks for the info, Daryll.

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Great info. I have yet to see how my car does mpg There are days were it seems to burn more gas running around town. Then again I only have 2200 miles so I guess the engine is still in the break in phase...

 

Darryl,

It is curious that the price differential has not changed in Pittsburgh. Here in S. Florida the differential used to be $.10 per grade consistently (ie premium was $.20 higher than regular). Now it varies more by station, but the differential between regular and premium is at least $.30 or more per gallon. I try to seek out the stations that still have the $.10 a gallon differential even if their regular price is higher than the rest. Guess it's my way of protesting the others for the gauging.

 

I suspect gas prices are in flux everywhere as some sort of "new market" is developing at these much higher prices.

At any rate, the big surprise to me is that as long as the price of 93 octane remains "only" 30ish cents more than regular (with regular around $4), it's the better buy...or at the very least it's a wash but better since the vehicle is supposed to run on it.

 

Yep, the differential here in the Dallas/Ft. Worth area was also 10 cents for years, but now everyone has jumped on the 15-cent bandwagon.

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Wow! At a mere 15 cents more premium is an even better bargain and makes my finding (that premium actually pays for itself or at least doesn't cost more) even more valid.

 

No - by "15-cent increments" we mean mid-grade is 15 cents more than reular and premium is another 15 cents more than mid-grade.

IOW, premium is 30 cents more than regular.

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Ah! About the same as here.

 

Cheers. I just broke the $5.50 barrier up here on Thursday.

http://www.hypermilers.com/


VL