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Old 09-03-2018, 08:04 PM
namelessman namelessman is online now
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Location: northern california
Join Date: Dec 2004
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Another perspective is that, assuming ECU takes care of adjusting to 87 versus 91, when cost savings is bigger than the decrease in mpg, then it will be worth it.

E.g. 87 versus 91 has 10% difference in mpg, then fill u with 87 when price delta is more than 10%.

Around our area 87 seldom goes 10% below 91.
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