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87 vs 91 (or 92) Octane? - READ ONLY

74 messages,  Last post on Jun 19, 2012 at 4:11 PM

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What is this discussion about? Gasoline

Messages Page 6 of 8

#45 of 74 Re: another POV [steve_] by andysd

Dec 15, 2011 (8:42 pm)

Replying to: steve_ (Dec 15, 2011 8:39 pm)
Since you've read the European Car test, I'm surprised you don't give it any credence. A five per cent increase in horsepower is not about seat of the pants.

#46 of 74 Re: another POV [andysd] by steve_ HOST

Dec 15, 2011 (8:51 pm)

Replying to: andysd (Dec 15, 2011 8:42 pm)
And what's the margin of error on that number? Should we add (or substract) one percent? Three?
 
Fun stuff, got any more links anyone?

#47 of 74 Re: another POV [steve_] by andysd

Dec 16, 2011 (8:57 am)

Replying to: steve_ (Dec 15, 2011 8:51 pm)
Steve, as to more links, I just googled extensively, and find unanimity in the position that using premium where not required by the manufacturer is a waste of money.
 
However, I am going to continue my personal test with my 2011 Honda Fit, to calculate mpg using 91 for comparison, and to write C&D to see if they'll do a test to confirm or refute the recent European Car mag test. I'll also refer to C&D's own 2001 test.
 
If I were a car commuter where fuel cost were an economic consideration, I wouldn't think for a moment of using premium (unless unexpected reports come from this forum of more economy with premium).
 
I do hope others will run comparative mpg tests, and advise this forum.
 
Just a personal decision, but I'm also going to continue to evaluate the seat of the pants indication that my Fit is more powerful. I drive this car in such a way that paying a little more for gas would be worth it to me. On many weekends, with other real sports cars, we push the mountain road curves. With no desire to collect speeding tickets, we do not drive at high speed on the straights.
 
I believe the contributors who say their cars run smoother on premium, that it applies to certain engines. The literature indicates that high mileage cars do run smoother on premium due to build-up of carbon on the pistons and cylinders, effectively raising the compression ratio.
 
Our 2011 Accord SE is so smooth, though, and I wouldn't use more horsepower if I had it, so I don't see any reason to even try 91 in it.
 
I also have a '99 Camaro Z28 I special-ordered new 13 years ago, in which I've used regular gas almost all its life. It runs fine on regular, which is permitted by the owner's manual, and I don't have any need or desire for the full 305 h.p.

#48 of 74 Re: another POV [andysd] by steve_ HOST

Dec 16, 2011 (9:40 am)

Replying to: andysd (Dec 16, 2011 8:57 am)
where fuel cost were an economic consideration
 
Well, some people run a higher octane just for that reason - they report getting better mileage. But the price differential has to be just right; usually that's a dime but it varies a lot.
 
For the same reason, some people run the ethanol free stuff if they can find it, because their gas logs show the extra cost of the gas is made up by the higher mpg.
 
I had a Fit Sport for a weekend and it seemed peppy enough. On my test drive of the Fit automatic, it was such a dog with three people in it that I'd want to switch to premium, Techron, Heet, aviation gas, vodka - anything to get it where it could merge on the freeway.

#49 of 74 Re: another POV [steve_] by andysd

Dec 16, 2011 (10:12 am)

Replying to: steve_ (Dec 16, 2011 9:40 am)
Around San Diego, there's about a 6% markup for premium, so you'd have to beat that with improved gas mileage. Non-ethanol not available in California.
 
The second gen Fit like mine has a little more h.p. at 117, and with the manual transmission feels pretty strong. You can't be afraid to wind it up to 7,000 max rpm where it is still very smooth. Really a fun car. I have 17" wheels and 215/45 Kumho SPT sport tires. I didn't buy the wheels/tires for the Fit, but had them in the garage for 7 years from a weak moment of buying for an '04 Civic I had at the time.

#50 of 74 Re: another POV [andysd] by steve_ HOST

Dec 16, 2011 (10:31 am)

Replying to: andysd (Dec 16, 2011 10:12 am)
Hey, there's a whopping 5 "pure gas" stations in California.
 
Maybe we'll get back out that way some day and we can meet for coffee at the Hob Nob Hill and compare gas logs (my wife is from La Mesa but all her relatives moved, durn it)

#51 of 74 Re: another POV [steve_] by andysd

Dec 16, 2011 (10:56 am)

Replying to: steve_ (Dec 16, 2011 10:31 am)
Steve, are Hosts employees or volunteers?
 
You're right about those five ethanol-free gas stations in CA. I reported them a few days ago, and forgot about them, because I've read ethanol is in all gas in CA, which is what the reference says that I pasted below.
 
Ethanol in gasoline seems to be a complicated and controversial issue, dangerous for boats with fiberglass tanks - but boaters with gasoline engines have no choice except to replace their fuel tanks with stainless steel. Here's a reference:
 
Ethanol Free Premium Unleaded Gasoline Coalition
 
    California Is Not A Mandatory Ethanol State
But It Might As Well Be
 
California does not have a mandatory ethanol blending law, but it should because ethanol is already in all of the gasoline in the state. The California Air Resources Board has an agreement with the EPA to blend ethanol into all of the gasoline in California at the 5.7% level. That level has been changed by a California law that allows the distributors to go to E10 by 2010 and they surely will for the economic benefit to them. It is unfortunate that the greedy ethanol companies and the oil companies pay no attention to the known problems with ethanol in gasoline. There are no exemptions in the California agreement and no requirement for labeling pumps, so you get problems like this.
Prohibit Ethanol Blending In All Premium Unleaded Gasoline
 
Every mandatory E10 state has exemptions to their blending law, because there are a number of piston engine applications that should not, and some that cannot, use ethanol blended gasoline. Unfortunately the exemptions are not uniform. They vary from only one exemption in Washington, aircraft, to a universal exemption of premium unleaded in Missouri. All states exempt aircraft usage, but most states like Oregon and Washington make it almost impossible to get unblended gasoline. Oregon is the only state that allows for unblended regular and premium gasoline for the exemptions, and then makes it almost impossible to get any unblended gasoline. All other mandatory ethanol states just allow clear premium unleaded gasoline for the exempted classes.
 
The following piston engine applications should not use ethanol blended gasoline:
 
    Any 2 cycle engine used in tools, watercraft, snowmobiles, etc., or small 4 cycle engines.
    Any engines used in an emergency stationary engine application like a generator or a pump, especially in a humid climate.
    All watercraft. Ethanol blended gasoline should never be used in a marine environment.
    Antique and classic cars and classic motorcycles.
    All aircraft.
 
All of these users must be able to get ethanol free (E0) gasoline. If you live in a state without a mandatory ethanol blending law, you have no exemptions, ethanol will eventually be blended into all of your unleaded gasoline and there is no requirement in EISA 2007 to label gas pumps with ethanol content.

#52 of 74 Re: another POV [andysd] by robr2

Dec 16, 2011 (11:21 am)

Replying to: andysd (Dec 16, 2011 10:56 am)
Here in MA, ethanol is blended in at 10% as a replacement for MTBE. I believe that is what they did in CA as well. Both are oxygenates but MTBE can damage groundwater supplies with a very low concentration.

#53 of 74 Re: another POV [robr2] by fezo

Dec 16, 2011 (4:56 pm)

Replying to: robr2 (Dec 16, 2011 11:21 am)
We're another one of those all ethanol states. Can't buy straight gas no matter how hard I try...

#54 of 74 Re: 87 vs Higher Octane [andysd] by oldbearcat

Dec 16, 2011 (10:07 pm)

Replying to: andysd (Dec 15, 2011 5:36 am)
When I use 87 octane gas on my Pittsburgh runs, the CRV typically gets 24.5 MPG. When I use premium - I use 93 Octane.
 
Regards:
Oldbearcat

Messages Page 6 of 8

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