: Who uses regular gas



alfon
07-02-2013, 01:52 PM
Just curious who uses regular gas in their Volt. I know that the current Chev Impala
has over 11:00 to 1 compression ratio and is designed to run on regular gas. I believe
the volt has 10:5 to 1 compression ration and is required to use premimum gas.

Seems to me that one can use regular gas in the Volt with no ill effects, especially if it is
designed to be a generator and not main propulsion as a regular internal combustion car, i.e.
the new Chev Impala.

I wonder if any scientific stats have been conducted over time comparing the mpg's with regular gas
compared to premimum gas.

I have heard that the main concept for premimum gas is that it has a longer life span than regular gas
and some owners of the Volt have the same gas in their tanks for over 6 months or so..

David B. Kelting
07-02-2013, 02:11 PM
I buy so little gas that I don't concern myself with the higher cost of premium gasoline. But it's just like you say, the premium gas last longer and you get better MPG (offsets the higher cost).

SharkVolt
07-02-2013, 02:16 PM
The Volt will get better mileage, even with the increased price, with premium gas.

However, it's computer can retard the ignition with regular gas, so there are no other problems, other than the lower mileage, and possibly poorer lifespan of the gas for prolonged periods.

mk2
07-02-2013, 02:17 PM
I hadn't heard that premium was required. The guy I bought my Volt from, who was the only dealer in the area that actually taught ME something about the car instead of the other way around, recommended I use premium if it looked like I wouldn't be running the 'genny' often because it lasts longer. Other than that, use what you want.

solar_dave
07-02-2013, 02:23 PM
From page 9-57 of the 2013 owners manual:



Use premium unleaded gasoline with a posted octane rating of 91 or
higher. If the octane is less than 91, you could damage the engine.
If heavy knocking is heard when using gasoline rated at 91 octane or
higher, the engine needs service

Use of Seasonal Fuels
Use summer and winter fuels in the appropriate season. Driving or
starting could be affected if the incorrect fuel is used. Drive the
vehicle with the engine running until the fuel is a half tank or less, then
refuel with the current seasonal fuel

Gasoline Specifications
At a minimum, gasoline should meet ASTM specification D 4814.
Some gasolines contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl (MMT). We recommend
against the use of gasolines containing MMT. See Fuel Additives
on page 9‑58 for additional information.

garyg
07-02-2013, 02:36 PM
I strongly suggest you use only premium gas as recommended.

but if you were going to try and get out of it anyway, make sure it is cold outside and you dont go thru much of it.

if you hear the engine knocking from pre-ignition, it could easily be too late.

Dairine2003
07-02-2013, 02:45 PM
I use 91 octane only. I figure that the $1.60 or so extra cost for a full tank refill will never offset the price of a new engine or other costly repair. Just seems silly to buy such an expensive car and then skimp on a couple bucks, especially at the risk of having to spend a whole lot of money later.

Kinda like doing maintenance on ICE cars or rotating your tires. You can pay $40 now or $400 later - it's your choice. :)

hamchief
07-02-2013, 02:46 PM
In the week after hurricane Sandy, we here in Long Island experienced a fuel shortage (real or fabricated). I HAD to fill up with regular (almost a full tank). I did not notice any ill effects during that tankful (~2 weeks) but I felt better reverting to the Owners' Manual mandate of premium on subsequent tanks.

BAZINGA
07-02-2013, 02:50 PM
Why would anyone scrimp on gas octane when the Volt uses so little. Read the Owners Manual.

Loboc
07-02-2013, 02:58 PM
Since I use so little gas, I get the max benefit from the grocery store discount. I paid $3.23/gal for 91 octane premium on the last fill. I therefore use premium exclusively.

flmark
07-02-2013, 03:26 PM
Because it uses so little gas...
...I sometimes FORGET to put in premium. When I do this, as soon as I burn some fuel, I go back and fill up the rest of the way with premium. I can't say I worry about it much. It's kind of like when I get soda at a fountain, I fill up part of the way with diet cola (lower sugar) and the rest with regular (better taste). In the end, the dilution offsets the extreme.

As others have said, I would not take the 87 octane shortcut regularly, or on purpose.

Neromanceres
07-02-2013, 03:26 PM
Just curious who uses regular gas in their Volt. I know that the current Chev Impala
has over 11:00 to 1 compression ratio and is designed to run on regular gas. I believe
the volt has 10:5 to 1 compression ration and is required to use premimum gas.


Not a good example. The Impala engine uses Direct Injection while the Volt engine does not. Direct Injection allows the fuel to be injected just before combustion at very high pressures. As the fuel vaporizes it has a cooling effect allowing the engine to run at higher compression ratios without engine knock to improve volumetric efficiency.

The Volt can run on regular gas with no issues but the ignition timing may need to be retarded to prevent engine knock (this impairs engine performance and efficiency). In most situations the cost difference in regular to premium is not enough to offset the efficiency losses. Also regular gas typically has a lower shelf life than premium gasoline.

itzdaniel
07-02-2013, 04:00 PM
Jesus people, go look up Volt deep dive on youtube, they explain why premium is needed. You spend 40k on a car and you go cheap on 20-30 cents? Sounds like you should have bought a Cruze instead.

Sonicman
07-02-2013, 04:35 PM
Jesus people, go look up Volt deep dive on youtube, they explain why premium is needed. You spend 40k on a car and you go cheap on 20-30 cents? Sounds like you should have bought a Cruze instead.

Agreed. No way am I running an octane experiment on my $40K Volt to save a few bucks. I trust that the Volt engineers tested this extensively and there's a good reason they only recommend premium.

adric22
07-02-2013, 04:40 PM
We fill up the tank every 3 or 4 months. We usually put in about 6 gallons at that time. It honestly isn't enough money for me to care about the price difference. However, if I used gas every day, then I might care.

Dairine2003
07-02-2013, 04:42 PM
We fill up the tank every 3 or 4 months. We usually put in about 6 gallons at that time. It honestly isn't enough money for me to care about the price difference. However, if I used gas every day, then I might care.

I think even if I used gas every day, I would still pay the extra couple bucks. I figure it this way - if someone uses gas every day, they are most likely still saving money over a prior car that used even more gas before they bought a Volt!

deekster_caddy
07-02-2013, 05:17 PM
I've seen enough octane experiments to say that if they call for 91, use 91. When people under-octane, yes the knock sensors retard the timing to compensate for the lower octane. Do you know how this works? The knock sensor is a microphone. It can hear detonation (fortunately) before we can. It hears the detonation, retards the timing a little. Then the computer tries to bring some timing back to see if the detonation is still there. If it is, remove timing (losing performance). If not, add a little more back. Detonation again? Remove some more timing...

This repeats and repeats and after 75000 miles your car "ran just fine" on lower than recommended octane but why does it need a new head gasket? What a piece of junk!

Fortunately you don't typically run the ICE in the Volt as much so it will take longer for your head gasket to fail. Sorry to the next owner. It's their problem.

(in fact, I know of many cars that said 87 octane was okay but their knock sensors were working overtime anyway, until I had their owners try 89 octane...)

kordichb
07-02-2013, 05:32 PM
I havent seen regular gas since the 80's

volt3939
07-02-2013, 06:27 PM
From page 9-57 of the 2013 owners manual:

Seasonal Fuel? I buy 3 gallons every summer and carry it around 'til Xmas when I burn about 1/4 gallon visiting relatives, then come July I run around on gas for a few days and then buy another 3 gallons for next year. Last year it was $12.80, this year it was just $11.80 for premium...

alfon
07-02-2013, 06:58 PM
Not a good example. The Impala engine uses Direct Injection while the Volt engine does not. Direct Injection allows the fuel to be injected just before combustion at very high pressures. As the fuel vaporizes it has a cooling effect allowing the engine to run at higher compression ratios without engine knock to improve volumetric efficiency.

The Volt can run on regular gas with no issues but the ignition timing may need to be retarded to prevent engine knock (this impairs engine performance and efficiency). In most situations the cost difference in regular to premium is not enough to offset the efficiency losses. Also regular gas typically has a lower shelf life than premium gasoline.

So the Volt could use the technology of a direct injection engine and be able run on regular gas and be far more
fuel efficient as well. Sound like the next move for GM Volt in the upcoming model years. I don't think anyone would
complain about it...

Steverino
07-02-2013, 07:00 PM
Save a penny, spend a dollar, LOL.

GM has zero incentive to recommend premium other than for the fact the engine is tuned to run best and more efficiently on premium and it will prevent engine issues during the warranty period. Even if the Volt didn't use so little gas, why anyone would want to skimp on the gasoline grade against the manufacturer's express requirement is beyond me.

Upper5Percent
07-02-2013, 08:23 PM
In Vermont the main reason to use the premium fuel, as recommended in the operator's manual, is that we have several stations who have NON-ETHANOL premium!!!...no ethanol issues from the fuel sitting around forever, or at least six months...:)

labnjab
07-02-2013, 08:32 PM
I always use shell vpower and always will. I got in the habit of using premium with my 2004 Supercharged Monte Carlo, so when I traded it in for the volt, having to use premium was no big deal, especially since i'm only buying 5 gallons every 3-4 weeks now instead of 12-15 gallons a week with my old car

bonaire
07-02-2013, 09:50 PM
I put in some 89 octane a while back and could feel the engine running rougher. Back on 91 and its better. Even better with Sunoco 93.

Neromanceres
07-02-2013, 11:35 PM
So the Volt could use the technology of a direct injection engine and be able run on regular gas and be far more
fuel efficient as well. Sound like the next move for GM Volt in the upcoming model years. I don't think anyone would
complain about it...

GM apparently evaluated direct injection for the 1.4L engine but at the time they felt the increase in cost was not worth the increase in fuel economy.

HiFlite
07-03-2013, 11:44 AM
Just curious who uses regular gas in their Volt. I know that the current Chev Impala
has over 11:00 to 1 compression ratio and is designed to run on regular gas. I believe
the volt has 10:5 to 1 compression ration and is required to use premimum gas.

Seems to me that one can use regular gas in the Volt with no ill effects, especially if it is
designed to be a generator and not main propulsion as a regular internal combustion car, i.e.
the new Chev Impala.



Analogies work except when they don't. (If I can take an elevator to the 100th floor of the Sears tower, why not build an elevator to the moon ...)

One huge difference between the Volt and Impala engine is the the Volt engine is used at high load (full throttle) virtually all the time. Try that in an Impala and besides the speeding ticket and likely death of the driver, the engine will scatter itself all over the road.

HiFlite
07-03-2013, 11:50 AM
GM apparently evaluated direct injection for the 1.4L engine but at the time they felt the increase in cost was not worth the increase in fuel economy.

That is probably true. A 5% fuel savings on an engine that is only used 25% of the time isn't worth much.

Also, there are problems with DI engines coming from the fact that the intake valves on a port-injected engine are both cleaned and cooled by fuel "wash" over them and this is not the case with DI. Even many expensive DI (German) engines are getting famous for losing power/compression over time when the intake valves get crudded up, premium or not. Same story with the much small holes in the DI injector nozzles compared to PI.

alfon
07-03-2013, 12:12 PM
So, I take it that the Volt can run on regular gas, but only in a pinch. If you
do run regular gas I am sure the check engine light will eventually come on. So when this
light does come on probably one full tank of premium gas will probably reset it.

Steverino
07-03-2013, 12:35 PM
So, I take it that the Volt can run on regular gas, but only in a pinch. If you
do run regular gas I am sure the check engine light will eventually come on. So when this
light does come on probably one full tank of premium gas will probably reset it.

Correct, it won't kill the engine and can be used in a pinch. The owner's manual recommends adding premium as soon as possible.

scutzi128
07-03-2013, 01:35 PM
I drive a lot and use regular...my MPG is the same with regular as it was with premium. This is over about a 2 month period using each grade and about 30 gallons of each. It is my opinion that GM specs premium because it lasts longer before going stale but if you fill your tank every month or so this should not be an issue.