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I have been trying to read the (mostly) archived messages about the topic but it seems like people are split about using premium gas vs regular, 50-50.

In my few weeks of testing, I found some of the claims about cost of premium gas offsetting itself by giving you more miles, quite the contrary. When I fill up with 91 octane gas (mostly from SAM'S Club), I see the gas consumption is more than filling up with regular gas. (Say ~170 miles on premium vs ~180 on regular gas). My driving range is quite long and a tank of gas lasts me a week tops. So having stale fuel in my tank is not a concern to consider for me.

Do I really get any benefit from using premium gas ? Is the Volt engine spark plug timing adjusted for premium gas ? If yes why do I feel like I am burning more gas on Premium grade ?
 

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The Gen 1 book says to only put premium in it. Seems like following that instruction would be a lot cheaper than needing a rebuild.
 

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I'm not sure. I filled up this morning on my way to work and accidentally put 87 octane in the tank. We cant get 91 here, so I typically put 93 octane in.
 

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You are only 233' above sea level so your octane requirements are higher than those of us further inland at higher elevations.

In any event this topic has been discussed to death, it is unlikely you will get Jesus to come to your house and tell you its OK, and GM certainly won't.

Its your car, do what you want, but if you are like me you will likely walk the line and keep the octane a bit above 87.

In my case 88-90, I usually have some sort of mix of E85/87/89 & 93 octane gas mixed together.

Never had a single issue using my fake midgrade fuel
(that conveniently costs the same or less than real 91 as e85 is 50 cents cheaper than 87 gas on a per gallon basis)
 

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You are only 233' above sea level so your octane requirements are higher than those of us further inland at higher elevations.

In any event this topic has been discussed to death, it is unlikely you will get Jesus to come to your house and tell you its OK, and GM certainly won't.

Its your car, do what you want, but if you are like me you will likely walk the line and keep the octane a bit above 87.

In my case 88-90, I usually have some sort of mix of E85/87/89 & 93 octane gas mixed together.

Never had a single issue using my fake midgrade fuel
(that conveniently costs the same or less than real 91 as e85 is 50 cents cheaper than 87 gas on a per gallon basis)
You shouldn't be using E85 in a volt as far as I know. It's octane rating is high enough but it's 85% ethanol. The volt isn't a flex fuel vehicle as far as I know.
 

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I personally think GM has aimed high with the premium recommendation in order to ensure that the fuel will still work after losing some amount of octane during long storage intervals (the Volt is designed for up to a year of storage in the car). I believe the car can handle 87 if you keep it fresh. But YMMV.

Be alert for knocking or performance issues if you try it.
 

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I heard as above states it is for fuel stabiliy as well slightly better mpg. knock sensor will keep it from knocking by retarding the eng timing.

On long trips, I go put the cheap since it wont stay around long and the mpg is unnoticeable. In the winter I will put lower grade in because it doesnt really need it when it is cold and the gas is mostly used for heat.
 

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The Volt 1 requires premium, there is really no argument here. Use premium. The engine design requires it.

I am pretty certain octane rating doesn't change much over 1 year old fuel stored in the Volt gas tank. I don't think fuel aging has anything to do with the premium requirement or the Volt 2 would also use premium. All I could find was a paper with a study of 25% ethanol and octane after 6 months was about the same, slightly lower due to evaporation of the Ethanol (which is higher octane than gasoline). In the Volts sealed system this will happen much more slowly.
 

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I have been trying to read the (mostly) archived messages about the topic but it seems like people are split about using premium gas vs regular, 50-50.

In my few weeks of testing, I found some of the claims about cost of premium gas offsetting itself by giving you more miles, quite the contrary. When I fill up with 91 octane gas (mostly from SAM'S Club), I see the gas consumption is more than filling up with regular gas. (Say ~170 miles on premium vs ~180 on regular gas). My driving range is quite long and a tank of gas lasts me a week tops. So having stale fuel in my tank is not a concern to consider for me.

Do I really get any benefit from using premium gas ? Is the Volt engine spark plug timing adjusted for premium gas ? If yes why do I feel like I am burning more gas on Premium grade ?
This is what the motor is tuned to run/burn.
 

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ub)
Do I really get any benefit from using premium gas ? Is the Volt engine spark plug timing adjusted for premium gas ? If yes why do I feel like I am burning more gas on Premium grade ?
No benefits from my 20+ years of experience in running 87 octane in cars that "require premium gasoline" - from 2012 Volt, 2013 BMW 328i, 2000 BMW 740i, 2000 Land Rover Discovery, and on and on.

I have one of the highest charge sustaining MPG on Voltsats for 2012 Volt (41.28 MPG lifetime) and 2014 ELR (37.80 MPG).

For what it's worth, I used to buy crude oil for Texaco refinery in Wilmington (now Tesoro), and part of my duty as engineer was gasoline blending. The biggest "collusion" oil companies have is the marketing hype on premium gasoline and "Top Tier Gasoline".

For your driving pattern, knock yourself out with using 87 octane gasoline. It will not harm the little four banger engine in 2013 Volt.

Oh, I almost forgot, I had the same conversation with multiple project engineers at GM's Advanced Powertrain Technology Center in Torrance. No one there objected to using 87 octane gasoline on first gen Volt.
 

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Do I really get any benefit from using premium gas ? Is the Volt engine spark plug timing adjusted for premium gas ? If yes why do I feel like I am burning more gas on Premium grade ?
I am by no means an expert on the subject of octane ratings; however:

  • The Gen1 and Gen2 Volts have different manufacturer recommendations -- for the Gen1, premium fuel is recommended (I don't know what precise octane rating, offhand), whereas the for the Gen2, GM recommends standard-grade 87 octane gas.
  • As turboguy327 says, E85 and lower ("flex fuel" or ethanol fuel) should not be used, as per the Volt's (Gen2) owner's manual. On other cars, mis-fuelling of this type can lead to damage to various engine components (fuel lines at least), and perhaps poor performance. That said, ethanol levels of under 15% are common even in regular gasoline, especially in urban areas and in the summer.
  • In most other cars that "require" high-octane fuel, my understanding is that this requirement mostly exists to provide an extra bit of performance, and that it's often possible to get by with standard-grade fuel. If the engine "pings" on such fuel, though, you should switch back to the high-octane version.
  • In most other cars that do not require high-octane fuel, my understanding is that using high-octane fuel will provide no benefit and may actually slightly degrade fuel economy.
Those last two points are from memory, which may be flawed. (Well, all of them are from memory -- but I recently skimmed/read my new Volt Gen2's owner's manual, so GM's recommendations for the Gen2 are fresh in my memory.) The Volt's design is different enough from a typical car's that I'm not sure the general rules that apply to other cars would apply to the Volt -- either Gen1 or Gen2.
 

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From what I've seen of knock on the first gen Volt (and I've done a lot of testing), the closer you are to sea level and the hotter the temps are, the more likely you're going to see knock and need 91 (or 93) octane. So Florida (at sea level) on a 90-100°F day, you'll probably need 93 octane to minimize engine damaging knock. One of our FL members checked for knock with regular gas (E10) on a hot day and it was scary how much knock he saw.

If you're above sea level (I'm at 900 ft) and the temps are more moderate say 60°F or colder, you'll have much less knock and less risk of engine damage. I'm not saying that 60°F in the Midwest is safe, but that you'll have a lot less knock. So from fall thru spring in the upper midwest, probably is safe on reg gas.

Nothing wrong with blending at the pump to get more octane (mixing E85 with E10 to get 91+ octane), but the sweet spot will probably be about E30 (approx 92 octane). Blends higher than E60 will require a custom tune and you'll need to add a lot more timing (2-15°, depending on rpm and load) to take advantage of the higher octane and get descent mileage. Stock engines will produce a CEL at E60 or higher. Bear in mind our vehicles were designed with E85 in mind, but they never enabled it in the tune.
 

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No benefits from my 20+ years of experience in running 87 octane in cars that "require premium gasoline" - from 2012 Volt, 2013 BMW 328i, 2000 BMW 740i, 2000 Land Rover Discovery, and on and on.
The Volt requires premium fuel, the others recommend it for best performance. Like the 2000 BMW 740i manual says:
BMW engines are equipped with knock
sensors and will adapt automatically
to different octane ratings, provided
that the minimum octane requirement
(87 AKI) is met.
The gen 1 Volt manual states specifically it will cause damage using lower octane.

Good luck with your Volt.
 

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We had a 2014 Volt which we traded in a few months ago for a 2016 Volt. My wife used 87 octane in the Volt for at least the last
20,000 miles or so. Never had a problem and in the past mpg on premium and regular appeared to be the same, sometimes even a little more on 87 octane.

No longer an issue of course with our 2016 Volt which uses good old regular 87 octane...
 

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GM says to use premium in Gen 1 and some want to know if they can use regular. GM says use regular in Gen 2 and some want to know of they can use premium.


:rolleyes:
 

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I actually agree with colchino

I do not always blend e85 but when I do I end up with 15-20% ethanol mixed with e0 87 octane.
(yes I miss the blending pumps we used to have before 2007)

When I was 9000 ft above sea level I was definitely running 87 octane.

There are also times I keep the tank full of 93 but that's when the car isn't going to be driving on gas much.
 

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The choices around here are 87 octane; 89 octane or 93 octane. I usually buy 89 octane; maybe 87 if I'm going to burn it in the next day or two. Theoretically, one could do a 50/50 mix of 89 and 93 .... I tried that once :)
 
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