My LS460 MPG Experiment
#1
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My LS460 MPG Experiment
I've only completed 1 tank full of regular gas, but here is the preliminary results of my experiment:
As most of you know, I mix 50% 87 octane and 50% 93 octane to get a combined 90ish octane. I tend to tilt the mix to bump it slightly above 90. Using that mix I have consistently gotten about 17 to 17.2 MPG around the hills of Pittsburgh. Almost exactly the same as I got with my old 2004 LS430. This mileage was no better than when filling with full 93 octane.
I decided to take the experiment to the next level. I ran the car down to fumes then filled it with 87 octane. Yeah yeah I know all that crap about driving a $70,000 car and chintzing on gas. Chintzing is HOW I accumulated the wealth to support a $70,000 car lifestyle, etc.
Anyway, after 1 tank it appears that my MPGs dropped from 17.1MPG to 14.6MPG. Just under a 15% reduction in economy. The car doesn't seem to ride any different although I suspect after a NUMBER of tanks of 87 octane I might see some difference.
Anyway, around here (today...changes almost daily as we all know), 87 octane gas is $3.65 while 93 octane gas is $3.89 or about 9% more.
So the bottom line is that it APPEARS that 90ish octane is the peak of the yield curve for your gasoline dollar. Going to all "regular" gas actually costs more than mixing 93 and 87. And using 93 all the time is wasting a few percent (some might argue that it's too small an amount to worry about).
As most of you know, I mix 50% 87 octane and 50% 93 octane to get a combined 90ish octane. I tend to tilt the mix to bump it slightly above 90. Using that mix I have consistently gotten about 17 to 17.2 MPG around the hills of Pittsburgh. Almost exactly the same as I got with my old 2004 LS430. This mileage was no better than when filling with full 93 octane.
I decided to take the experiment to the next level. I ran the car down to fumes then filled it with 87 octane. Yeah yeah I know all that crap about driving a $70,000 car and chintzing on gas. Chintzing is HOW I accumulated the wealth to support a $70,000 car lifestyle, etc.
Anyway, after 1 tank it appears that my MPGs dropped from 17.1MPG to 14.6MPG. Just under a 15% reduction in economy. The car doesn't seem to ride any different although I suspect after a NUMBER of tanks of 87 octane I might see some difference.
Anyway, around here (today...changes almost daily as we all know), 87 octane gas is $3.65 while 93 octane gas is $3.89 or about 9% more.
So the bottom line is that it APPEARS that 90ish octane is the peak of the yield curve for your gasoline dollar. Going to all "regular" gas actually costs more than mixing 93 and 87. And using 93 all the time is wasting a few percent (some might argue that it's too small an amount to worry about).
Last edited by daryll40; 05-08-08 at 06:42 AM.
#3
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#6
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#7
What you might also try is a credit card that gives discounts for gas. I am one of the evil poeple that supports Exxon (please, don't burn my house down), but I put my gas on my Exxon card and get a 3% discount. I use the premium gas and that generally gets me down to the mid level gas price. I have heard other cards give back more credit than that.
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#8
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Actually, here in Pittsburgh the Giant Eagle Supermarket company has an even better deal that links all purchases (groceries and gasoline) to gas discounts. But your point is good. A REAL "value seeker" will do BOTH (buy gas with the best discount cards AND squeeze the optimum miles per octane!). Again, "seeking value" is how many, like me, get to the Lexus in the first place.
Last edited by daryll40; 05-08-08 at 12:17 PM.
#9
Daryl, that drop in mileage with the 87 gas seems too drastic. My guess is a combination of different driving and imprecise gas measurement are to blame. Try a few more tanks of 87, I suspect that that your measured mileage will improve to almost your 93 octane mileage.
#10
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It's very possible. I'll keep watching this and reporting in as I get numbers.
#11
I put the best fuel in that I can BP 93. I wouldn't put in anything less. What ever you decide, it's your car and your money. I average 21-22 MPG in the city now that it's warmed up here. In the winter, it was around 19-20 MPG
with BP 93 octane.
Craig
with BP 93 octane.
Craig
#13
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"I average 21-22 MPG in the city now that it's warmed up here."
"here" has to be some VERY flat place with a moderate climate.
"here" has to be some VERY flat place with a moderate climate.
Last edited by daryll40; 05-08-08 at 12:51 PM.
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