This is in response to these threads:
In the first thread above, I had mentioned that I would run my tests and gather more data again. In short, I was gathering data on mileage using different grades of gasoline. I waited until summer started and school was out, so my A/C usage and traffic patterns would all be similar. [ 1 ]
Vehicle: 2004 VW Passat. Manual Transmission. 4 cylinder w/ Turbo. VW recommends 91 Octane.
Prep: I waited until summer, so A/C usage and traffic would be consistent.
Conditions: Daily commute. Mostly suburban driving. Very Little Highway. Some start/stop.
Blend: I would fill up after using a quarter tank alternating between 89 and 93 octane averaging about 91 octane.[ 2 ]
Octane Miles MPG Time Average Fuel Fuel Price per Costco/BJ's Costco/BJ's Rating Driven Driven Speed Used Price500 miles Price Price per 500 Miles 87 521.5 28.6 19.617 27 18.234 $2.822 49.336 $2.795 48.864 89 568.1 28.6 19.183 30 19.864 $2.995 52.360 93 570.6 29.3 17.55 29 19.474 $3.126 53.345 $2.859 48.788 Blend 424.2 30.3 14.6 29 14 $3.061 50.503
Conclusion: Due to the better mileage with the blend, the cost per distance 87 octane and the blend (91) is negligible. While I could save money using 87 octane, I did experience sluggish acceleration and lessened performance. Personally, I’d rather spend a dollar more every 500 miles and know that my car will take off if necessary.
[ 1 ] We have had a heat wave here for the last week, which may have skewed the 89 Octane results.
[ 2 ] The Blend Data is not as complete, as we were about to take a road trip, and I didn’t want to skew the data with an additional 100 miles of Highway driving.
[ 3 ] Price take from AAA website for the Charlotte, NC region.
[ 4 ] Price recoded from the sign outside BJ’s last night.