SidCivic

Hi Civic Friends!

I just bought a 2015 Honda Civic LX Sedan CVT Automatic 1.8 Liter 4 cyclinder, live in sunny San Diego, California, and drive 80% highway miles. Already hit 5k miles in 2.5 months and looks like I'll avg. around 25k miles this first year. Looking to put the best type of gas in the vehicle from the beginning. Concerned most with mpg and maintenance; not necessarily performance since I'm not racing the thing. I have read that top tier gas is best and premium is not worth the slight potential mpg advantage over regular. The research online is very confusing and contradictory, so I thought I'd ask you all for your feedback.

1. What brand of gas do you recommend? - I have read that top tier gas sold at these retailers is better than tier 2 gas or gas at other gas stations. http://www.toptiergas.com/retailers/
2. What type of gas do you recommend (regular or premium)? - I have read that premium MAY provide SLIGHT mpg advantage over regular, but that the increase in mpg is not worth the added cost.

Sorry for any silly questions. First new Honda and trying to treat it right. Thanks for your help!

Poopies

iTrader: (4)

1. I use Shell nowadays, although I prefer QuikTrip as it is usually cheaper. I use additives too though.
2. I used premium on a road trip from Washington to Kentucky last year. I didn't notice any improvement. Keep saving your money!

SidCivic

Thanks Poopies! You use your own additives? So you fill up gas then add additives to your tank? Which additives do you add?

GolNat

iTrader: (7)

1.) Top Tier for me. Either Shell, Exxon or Valero.

2.) Regular. I think my MPG is worse with premium. It's over 50 cents more then regular.

ezone

Top Tier Gas, any brand on the list.
If you have a choice in your area, go for no Ethanol.

87 Octane. No need for more, the car is not designed to use higher.

Poopies

iTrader: (4)

I use 2 oz. of Lube Control's FP Plus with each tank. It can only be ordered online.

xRiCeBoYx

iTrader: (22)

1) Chevron, Shell, Mobil, Sinclair, Arco, whichever's closest at the moment. If I'm not hurting for gas at the moment and I'm in the area of cheaper gas (of those stations), I'll make the trip. So far, Mobil seems to be the cheapest around me. I used to use 76 a lot, but they've become among the hella more expensive stations around me.

2) 87 octane only. Gotta be careful, because a few stations in Utah (when I go on hiking/boarding trips up there) have 85 octane as the lowest.
89 is for suckers (seriously. forgot where I read it, but it's there to yield the highest profit margins, and that's it. Just a mix of 91 and 87 is all it is.)
91 will give you worse fuel economy since it burns at a slower rate to prevent detonation in higher compression/force induced engines.

I've used FP plus before and only noticed a decrease in mileage every time it was in my tank. No noticeable change from pre-FP Plus when I didn't. B12 fuel additive is the only thing I've used so far that has noticeably increased my fuel economy. I tried it at the recommendation of my gf's godfather (used to be an instructor at UTI). I am curious about the BG MOA110, though, since another user posted up about it in the LubeControl thread.

edit: list of top tier gas stations

brags

I use Shell gas because its a top tier fuell

SidCivic

GolNat & Ezone & Brags - Thanks for the regular 87 & gas station recommendations!

Poopies - 2 oz Lube Control, got it.

Rice Boy - Thanks for the detailed answer! I frequent the same stations you mentioned, but had no idea 85 octane even existed. Thanks for that tip. I will tell my wife who often fills it up. Also, thanks for the info on the B12 & BG MOA110. I will keep those in mind.

Bikergofast

Wondering this myself after reading the manual on my 2015 LX and seeing the no MMT warning. Problem is up here in Canada I'm not sure if we follow the same rules as US. I've got Ultramar, Shell, and Esso on my daily commute, and one private station (for now), so if any Canadians here know for sure who doe not have MMT pls let me know.

ezone

OMFG I wish I had not looked.



Article dated 2006?

Many scientific and engineering studies have been published over the years providing theories that MMT is detrimental to vehicle emission systems and public health, since burning fuels containing MMT will cause manganese particles to be emitted into the air. Manganese is known in the medical field as a potent neurotoxin.


MMT's manufacturer, now known as Afton Chemical Corp., has fiercely defended the safety of its product, and in 1998 won a $19-million out-of-court settlement after the Canadian government tried to restrict importation of MMT. Still, fuel companies have largely turned to oxygenates, including ethanol, as substitute octane-boosters. (Ethanol is also used in higher concentrations, such as the eight-per-cent blend sold by MacEwen stations and some others, as a fuel itself.)


Calls made to major fuel producers and distributors this week revealed that automotive fuels from Petro-Canada, Shell and Imperial Oil (Esso) contain no MMT. The majority of non-refining fuel retailers, such as Pioneer, Sunys and the like, purchase their gasoline directly from the big multinational refiners. So it's highly unlikely that you'll find MMT, no matter where you buy fuel in Canada.

http://www.canada.com/story_print.ht...e-27a849bf5de9

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I think this is the newest thing I saw, 2014, but it's company propoganda

"We've checked ourselves out and determined that what we sell is good for you and good for the environment. And we changed the name again so you won't suspect a thing."

• The result of the testing has shown that the body has mechanisms to handle a wide range of manganese intake, whether from inhalation or ingestion.
• While these mechanisms can be overwhelmed if exposures to manganese are very high, the testing confirms that the body can safely handle inhaled manganese at and well above exposures at environmental levels, whether mmt® is used or not. (studies show that HiTEC 3000 Series of mmt® fuel additive does not measurably increase ambient manganese in the air)

http://www.aftonchemical.com/Insight...ience_mmt.aspx

Mad Dog Tannen

Chevron is the best, other name brands usually come in a close second, Shell is one of the worst big names.

87 octane is all that is necessary. If your car doesn't call for higher octane, then you are wasting your money using it. Some of the Si engines may require higher octane due to their higher compression ratio or engine design.

Change your fuel filter if you didn't on your last tune up. It's probably the most neglected tune up part. And use preferably Chevron fuel injector cleaner every once in a while.

Mad Dog Tannen

Sorry Rice, but 91 does not give worse fuel mileage, and it doesn't burn slower. 91 does not detonate early under the higher compression of high performance engines. 91 is fine to run in a 87 octane engine, it is just a waste of money because it's more expensive and not required.

http://www.exxon.com/octane-rating

xRiCeBoYx

iTrader: (22)

That was my understanding of it. Extra detergents in the higher octanes, causing a slower burn, thus preventing detonation in higher compression/force induced engines. Looks like I have to educate myself a bit more on that.

The lower fuel economy if based on my personal experience running higher octane, most notably when my step-dad offered to fill my tank with 100 octane once.
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edit: then again, my organic chemistry class taught me that octane is just an 8-carbon long hydrocarbon chain, thus refuting the detergent aspect of my argument
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edit 2: alright, about to get a bit technical here, but I did a bit of quick research to explain octane vs compression.

Yes, you are right, it does take a higher compression for higher octane fuel to ignite spontaneously, hence the anti-knock properties of higher octane fuels.

Octane is technically a misnomer by chemical naming means (I had a brief stint as a chem major), but wikipiedia's use of iso-octane is still correct. Iso just means that instead of the 8 carbons being in a straight chain to fulfill the "octane" name, the other main carbons branch off from the chain (different conformation of a structure with an identical chemical composition). The isomer used to calculate is actually 2,2,4-trimethylpentane. It still has 8 carbons, but 2 carbons branch off from the second carbon in the base 5-carbon chain, and one carbon branches off from the 4th. The two hydrocarbons used in octane rating is a comparison to the relative concentrations of 2,2,4-trimethylpentane (henceforth iso-octane for ease of typing) and heptane, the latter of which is simply a 7-carbon long hydrocarbon chain.

The zero point on the octane rating scale has a 100:0 ratio of heptane to iso-octane. The reverse is true as well, 100 octane has a 100:0 ratio of iso-octane to heptane.
Fuels with >100 octane ratings are those containing alcohol fuels/methanol/etc. (don't ask how they calculate the extra octane rating, I didn't look that up.)

A study done by Penn State Department of Chemistry calculated the autoignition temperatures of heptane and iso-octane at 233.85C (452.93F) and 433.85C (812.93F), respectively, calculated at the same pressure, to avoid temperature calculation variances. The purpose of the study was to determine what molecular properties are involved in auto-ignition temperature, but I digress. With that data, In order to combust at the same temperature (assuming temperature within an engine is fairly consistent with a slight variance since nothing is truly perfect), iso-octane would have to be compressed at a much higher pressure in order to auto-ignite. Given a higher relative concentration of iso-octane to heptane, a higher octane fuel would resist auto-ignition than that of a lower octane.

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tl;dr: Mad Dog is right, I was wrong, but now much more educated.

Actual tl;dr of my research: Octane rating is based off of the ratio of 2,2,4-trimethylpentane (iso-octane) to n-heptane. More iso-octane => higher octane rating => higher resistance to auto-ignition of the fuel => higher resistance to engine knock in higher compression/force-induced engines. Completely unnecessary to run anything higher than 87 octane in a stock/mildly naturally aspirated Honda Civic, or anything boasting anything less than a, say, 11.0:1 compression ratio

Mad Dog Tannen

When it comes down to it, do what the manual says. Honda engineers know what they are talking about. And when in doubt, use premium.