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#35 of 74 Re: 87 vs Higher Octane [robr2]
Dec 14, 2011 (2:16 pm)
I hear you, but after about 17 years in and around NYC/Roslyn/Tarrytown, 3 years in the Navy, 5 years near the beach in Lomita CA, 11 years in Holland (still have the same ex-Dutch wife), 20 years in Saudi Arabia, a couple of years in Houston, a year in Calgary, we chose Socal in sight of the Pacific for retirement 27 years ago.
You probably wouldn't believe all the things we can do, e.g., within 20 minutes of twisty two-lane mountain and desert roads, that I enjoy every weekend on two and four wheels with fellow enthusiasts. We go over Mt Laguna's 6,000 feet almost every week where there is plenty of climate change, colored leaves, sign "Against the law to throw snowballs at vehicles."
#36 of 74 Re: Update 87 vs 91 (or higher) Octane [robr2]
Dec 14, 2011 (7:57 pm)
Whether I fill the CRV up with premium fuel or not depends on the price spread between the fuels. For a good while here, the price differential was too much to make it worthwhile.
In town, the car seems peppier as I noted, low end torque feels slightly better, and the hesitation is gone.
#37 of 74 Re: 87 vs Higher Octane [robr2]
Dec 14, 2011 (8:18 pm)
The best verification I have is that I make a 500 mile roundtrip to Pittsburgh once a month for business. I've used both fuels for a bunch of trips, and, the CRV consistently does better on premium gas. The best the car's ever done - I filled her up with premium outside of Atlantic City, NJ, and got 34.5 MPG running her 70 - 73 MPH on cruise - headed for home in WV. I suspect the gas I bought didn't have any ethanol in it, and, it's not available in my state. My CRV is a 2wd by the way.
#38 of 74 Re: 87 vs Higher Octane [oldbearcat]
by Stever@Edmunds HOST
Dec 14, 2011 (8:27 pm)
There are ~8 "pure gas" stations in WV (assuming the list is current). Not a lot.
#39 of 74 Re: 87 vs Higher Octane [oldbearcat]
Dec 15, 2011 (4:36 am)
That's good data. For comparison, can you say what your mpg is for the same trip using 87 gas? What octane was the premium you used? The (current) CR-V engine has a compression ratio of 10.5, pretty high, possibly leading to the conclusion that higher c.r. engines (specifying 87 octane) benefit relatively more from octane higher than 87.
I got the email address to send an email to the editors of C&D, and started a draft.
Dec 15, 2011 (4:17 pm)
"But what if you don't have a high performance vehicle? Will putting high octane premium gas in your car make it run any better? Well, mechanics say it could actually make your car run worse.
"They have sensors on what the combustibility rate is in the pistons and stuff, and it will screw up the sensors because the rate is slower than what regular gas fires at higher combustibility rates," said Fox Negaunee sales associate, Casey Massie."
Premium vs. regular gas, what's the difference? (FoxUP)
The comments there run the same gamut as here.
#41 of 74 Re: another POV [steve_]
Dec 15, 2011 (6:23 pm)
It's great that our Host, Steve, is contributing his ideas and info from links. Thank you, Steve. By the way, we need your help again if you can make that original link available. The way I pasted it in Msg #1 now goes to a subscription page for European Car! It worked for a while.
As to the question, "But what if you don't have a high performance vehicle? Will putting high octane premium gas in your car make it run any better?"
As a preliminary answer, none of the vehicles belonging to contributors to this thread are high performance vehicles, and they are reporting benefits. The car in the test that started this off, in Msg #1, is a VW Passat with the base Golf engine, the 2.5 5-cylinder. Mine is a Honda Fit. Oldengineer's is a Honda CR-V. Another is a "VW."
I'm not trying to push my personal idea, but instead am trying to go further with the test that reported benefit in the link referenced in Msg #1, and so far we are seeing real life evidence that there is benefit.
#42 of 74 Re: another POV [andysd]
by Stever@Edmunds HOST
Dec 15, 2011 (7:23 pm)
Hm, the link is still working okay for me.
Here's a text only cached version that may stick around for a while.
Car and Driver has looked at this before btw. Back in '01 they said "only a few vehicles calibrated for regular fuel can advance timing beyond their nominal ideal setting when burning premium." Performance gains were minimal (or negative in the case of an Accord in their fleet). Regular or Premium?
If you're still composing your note to C&D, you can ask them if their story still holds true with your higher combustion Fit engine.
#43 of 74 Re: another POV [steve_]
Dec 15, 2011 (7:37 pm)
Thank you, thank you, Steve. You must work 24 hours a day!
Yes, I'll reference the '01 C&D test, but we're getting current real life evidence from your forum contributors that it does help, just like the recent subject test concluded.
Regarding the V-6 Honda in the '01 C&D test, "The Accord took a tiny step backward in power (minus 2.6 percent) and performance (minus 1.5 percent) on premium fuel, a phenomenon for which none of the experts we consulted could offer an explanation except to posit that the results may fall within normal test-to-test variability."
I like the text version although it doesn't have the graphs.
From the recent European Car magazine test, the h.p. gain on the lowly base 2.5 liter 5-cylinder VW engine increased from 138 to 145! That's 5 per cent. And:
Does higher octane fuel make a difference on all vehicles? It did in this case. Because of VW's advanced electronics and highly adaptive engine management, the Jetta 2.5L has an elastic response to a changes in octane levels. Once we put in the 87 octane, we could feel the drop in performance - less responsive, less peppy, and overall just different. The engine instantly detected the reduced octane levels and adapted for standard performance. This analysis was based on more than 1,200 miles of driving over a week.
Switching between the two octanes allowed us to use the dyno to detect and confirm or refute any driving subtleties we noticed during the week. Even though the Jetta's gas tank flap advises 87 octane, the dyno graphs clearly show that running premium gasoline does have performance benefits including, a slight increase in fuel economy. In the end, you get what you pay for. If you want standard performance use standard gasoline. But if you want premium performance, pay for premium gas.
#44 of 74 Re: another POV [andysd]
by Stever@Edmunds HOST
Dec 15, 2011 (7:39 pm)
"we could feel".
That's a red flag for me and it really indicative of the placebo effect. I put premium gas in my car, so it must be running better. Back in the day, when I got a new pair of sneakers, I could run so fast I'd challenge my older brother to a foot race. Never beat him.
Testers should stick to repeatable results, not seat of the pants stuff.
Road and Track says "There's no benefit in octane higher than the recommended one (as systems generally adjust downward in response to knock, not upward until they hear it)."