My mileage seems to have reduced by about 10-15% on average with mixed driving (some aggressive some passive)--30 to 27. The biggest thing I've noticed though is that I can no longer get great mileage when trying. I used to be able to obtain 35-45 on long highway trips if I was being mindful of the needle, but those days are long gone. I find myself not pushing for the 35 number.
Overall though, the performance (efficiency) and performance (power) are still as amazing as ever.
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