Last post on Jun 19, 2012 at 3:11 PM
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#65 of 74 Re: 87 vs Higher Octane [andysd]
Dec 19, 2011 (9:03 pm)
Sorry I sunk your ship. IMO, the software upgrade will no longer let the engine take full advantage of the additional octane. I'm going to run a couple more tankfuls just to make sure. I have run into stations here selling 93 that was actually 87, and, the price differential is not that bad right now. I also did this exercise on a 2008 Saturn Aura (previous business driver) that was equipped with a 3.5 liter pushrod V6 with fairly high compression and VVT. Using 93 octane gas had no effect on its fuel economy.
#66 of 74 Re: 87 vs Higher Octane [oldbearcat]
by Stever@Edmunds HOST
Dec 20, 2011 (6:34 am)
That gets us back to the question of whether your engine, software flashed or not, is designed to take advantage of the higher octane. Do they still make winter blend fuel? Keep hearing reports that there's little need to change the blend anymore, with all the ethanol in most gas. But that would have hammered your last tank if it was "winter gas".
But what do I know; another 70 pounds and I'll be a 90 pound weakling.
#67 of 74 Re: 87 vs Higher Octane [oldbearcat]
Dec 20, 2011 (6:43 am)
With a final grasp at floating flotsam or jetsam, Oldbearcat, can you explain the 34.5 mpg run in the CR-V?
#69 of 74 Re: 87 vs Higher Octane [andysd]
Dec 20, 2011 (8:58 pm)
No, I can't - and, I've never been able to duplicate it since. I do take solace in the fact that, with both cars running on 87 octane gas, the CRV manages to get 4.5 more MPG than my stock 1948 Chevrolet Fleetmaster does.
Regards & Merry Christmas
#70 of 74 Re: 87 vs 91 (or 92) Octane? [andysd]
Jan 09, 2012 (5:51 pm)
Jan 9, 2012: I finally emailed the editors of Car and Driver, following:
In the light of European Car magazine's July 2010 positive result, this is to suggest you repeat your November 2001 test to determine whether using premium gasoline increases horsepower for engines that are not required to use it. The European Car test can be read on http://www.europeancarweb.com/tech/proven/epcp_1007_2010_volkwagen_jetta_proven/- viewall.htmlxx. In their test, using premium gas in a 2010 VW Jetta 2.5 L, dynamometer tests showed an increase of 8 horsepower!
I started what became a lively forum thread on this subject on Edmunds.com, Gasoline - 87 vs Premium. There seemed to be unanimity that such engines felt peppier but did not conclusively increase miles per gallon. My 2011 Honda Fit Sport 5MT definitely feels stronger with premium, and I wonder whether engines with higher compression ratio, like my Fit at 10.4:1, benefit more. Considering your success with the Fit in the 25 hour Thunderhill race, I hope you might use the Fit in your test.
As an aside, I love driving my Fit on the San Diego East County two-lane mountain roads, and it flies through the curves, more than holding its own compared to friends' expensive sports cars. I installed 17" Kosei Racing wheels with 215-.45 Kumho SPT tires left over from an '04 Civic, and removed the rear seats reducing weight by 70 pounds.
#71 of 74 Re: 87 vs 91 (or 92) Octane? [andysd]
by Stever@Edmunds HOST
Jan 09, 2012 (7:54 pm)
Heh, since Edmunds competes with Car and Driver for automaker ad dollars and has their own forums, you might get the cold shoulder by mentioning our forums.
Maybe they'll edit that part out and get back to you.
#72 of 74 Re: 87 vs 91 (or 92) Octane? [steve_]
Jan 10, 2012 (7:02 am)
Good point, Steve, but at least they have the whole story. Let's see if they do anything.
#73 of 74 My Last Words
Jun 03, 2012 (12:58 pm)
I started this thread after reading an article in European Car that showed a dyno increase in h.p. as the result of using premium gasoline where not required. In summary, I wrote Car & Driver to suggest they conduct another test, quoted in an earlier message.
All to no avail, and I'm signing off. I don't know the answer definitively, and probably never will . C&D never reacted.
Jun 19, 2012 (3:11 pm)
A journalist would like to speak to someone who fuels up with 85 octane and has experienced engine issues or a weaker performance at lower elevations because of it. If you use or have used 85 octane, and would like to share your story with a reporter, please send your daytime contact info to predmunds.com no later than Wednesday, June 20 at 2 p.m. Pacific/5 p.m. Eastern.