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MPG's on 89 vs. 91
I decided to pump a full tank of 89 octane at Chevron last week to test for differences in MPG & performance and compare it to that of 91 octane at Shell. Here are the results in the first 50 miles of driving.
With 89 octane, my average MPH was 27.7 and MPG was 18.8 With 91 octane and the same style driving the average MPH was 16 and MPG was 15.5. No noticeable loss in performance or "pinging". I knew what I was getting into when I upgrade from my 4cyl. 00' Celica GT to a 6 cyl. 08' G35. But I never expected to see any difference by pumping a mid grade octane compared to a premium octane. Any opinions fellas? |
Funny you should notice - I had a similar thing happen and no pinging........
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i only pump chevron/shell 93 oct. in mine.
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Was it on the same road? Maybe one was going uphills and the other going more downhills. It would be more accurate if you travel the same road using cruise control. Just a thought.
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The ECU will pull timing with lower grade fuel.
Keep in mind, you ARE losing power and MPG with lower octane, because the engine is not running at maximum efficiency. The ECU can only do so much, and low grade fuel WILL eventually cause damage to the engine. Just because you don't hear or feel pinging does not mean it is not happening; it has to occur before the ECU pulls timing. The knock sensor built into the car is MUCH more sensitive than the human ear. |
:doh: :46: 89 grade gas in a 40k car??
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I give you credit for even doing this I would NEVER put 89 in my car no matter what I was looking at. The damage that you coiuld cause is not worth it. An yes you would not hear any pining unless you have my old car 04 Max just traded dealer could not fix it 5 times..
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So... Here in Nashville gas has been scarce lately and I really needed some. I filled up with 89 since that was all that was available and put an octane booster in it from Advance Auto. I should be OK, right?
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the difference in average mph makes me think the difference in mileage...means absolutely nothing. if you want to compare, you need a somewhat controlled driving situation.
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your average speed difference gives your test zero credibility. An average of 16MPH indicates a some major stop and go traffic. Do a highway test and report back your results. |
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91 octane?
Where do they offer 91? I'm in SW FL and all they offer are 89 and 93. |
91 is "premium" in California.
Sucks for STI and Z06 owners... they're supposed to be on 93... |
I'm curious...
What's the average price of 91 in Cali? 93 here is averaging about $4.10/gallon |
I just filled up yesterday at $3.75 (cheapest in my area)
Average for 91 is about $3.9x. www.gasbuddy.com |
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