Performance on 1,600 mile trip with 2012 Volt

[DCFusor]

Note, you DO get better mileage with non-ethanol gasoline, which you can get in some places.

I live at 2400 feet elevation. In this car, and even in my 2010 Camaro SS (which also specifies super), there is just no need (and no point paying extra), as the thinner air makes for an effectively lower compression ratio anyway, and there's only so much spark advance that helps mileage (controlled by the computer). If you're down at sea level, you should use the recommended octane, but do try to get it without ethanol. When I can find it here, it's usually 10c a gallon more than the alky stuff. This might change as the price of corn is at all time highs right now...

For me, at my altitude, 91 seems best, I can skip the 93. But 91 does do better than 87, all things considered.

And you can just leave it in MM going up the hill, all sport mode does is remap the accelerator, it doesn't give any more power with it mashed to the floor than normal or MM does, it just feels easier. And that's easier on the batteries than S mode, since some of the power is coming from the engine - at high speeds, the engine might even be clutched in directly in MM so there's no round trip loss for that fraction of the motive power either.

[saghost]

When I visit the top tier gasoline website, it states that top tier gasoline is just a higher detergent level and not any additional stabilizers or ignition retardants.

http://www.toptiergas.com/

You can choose to believe what you wish. I don't think that 87 octane will kill the car any time soon. Here's a quote from GM's Vehicle Line Director (chief engineer) a couple years ago, on both efficiency and stability (which you would have seen if you'd read the link I gave earlier:

http://gm-volt.com/2010/07/30/why-th...mium-gasoline/

“The Volt is all about efficiency,” he said. “Premium fuel offers the opportunity to have a little bit more spark.”
“Ninety one octane fuel also offers the opportunity to be a little more efficient, he added. “So technically its a five to ten percent fuel economy improvement the few times that most people will run the range extender.”
Posawatz also claimed the increase is cost will be offset by the efficiency gains.
“Based on our calculations the fuel economy and efficiency gains you get will effectively compensate for the extra cost of premium fuel,” he said
Additionally, premium fuel is apparently slower to go stale.
If people are not using the extended range capability a lot, the premium fuel does last a little longer,” he said

[sinnombre]

When I visit the top tier gasoline website, it states that top tier gasoline is just a higher detergent level and not any additional stabilizers or ignition retardants.

http://www.toptiergas.com/

I think the top tier 87 has enough detergents and stabilizers and the 93 octane may actually contain more ethanol . My theory is if you buy 93 octane it will degrade to 86-90 after several months because of the ethanol and other components . If you left 86 octane in your tank for 6 months it may degrade below a safe threshold .

[Lee Willis]

The longest trip I have taken is about 800 miles - central NC out US 1 to Rocky Mount and up 95 to the Washington DC area then around there for several days and back. The first 27 miles on electric and then 740 on gas while in MM. Temperatures where mostly in the 90s but I leave the AC on eco (seems to be all we need until it gets to 100). My mileage on gas was 43.9, most of it on the Interstate - I was impressed.

Although I paid attention to all the technology and 'optimization' of features early on, I not longer do any of that. I fill it with premium because the manual says to. I leave it in "D" not "L" - I brake nicely enough I dont need the car re-gening for me. I drive it like a normal car, forget all the technolgy, and just don't think about all that . . .

The only thing I do that is Volt or EV specific, at all, is run always on the highway in MM, for two reasons. First, I like the reserve of battery power available for peaking power: I have driven the car in normal with nothing left in the battery and the ICE can only develop about 100 Hp or so - my car turns into a slug on the highway. In MM it has a deep reserve of all its HP - its not a rocket but it does better if I need to pass uphill ot something. Second, I like having about 14 miles of electric left if I want it.

[Ladogaboy]

I've only run premium up to this point, and my main concern with switching is potential warranty issues. If, for whatever reason, my ICE goes out, and I was using 87 octane, GM could deny warranty coverage. No? That being said, the recommendation premium makes sense because octane ratings will decrease with time. Some of you who have had the same tank of premium since the last time you visited the dealer probably have an octane rating closer to mid-grade at this point.

Anyway, I'll be taking an 1,100-mile trip pretty soon, and I'll only have access to a couple of charges over the length of the trip. I'll be sure to share my experience.