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I have had my volt for a bit over a week and went on my first out of town trip. I was not too happy with the mileage I got on Hold mode.

On the return trip I went from Albany Oregon to Eugene Oregon (About 40 miles of straight, level freeway) on I-5 with cruise set to 69. I had the AC on ECO (It was about 78 deg out and it stayed on low). Total weight of passengers and cargo was about 400lbs. My mileage for that was under 35mpg according to the trip meter that I reset as I entered the freeway. I was under the impression I should get about 50mpg if I get up to cruising speed before going on hold.

The trip there was on a back road in mountain mode (It is a hilly back road). My stats page is Here

Am I missing somthing?
 

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The power required to overcome aerodynamic drag is proportional to velocity cubed. In my opinion, 35 MPG is pretty damn good for going 69 MPH.
 

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I haven't tried getting to cruising speed then putting it on Hold. I can see how that could help some as the acceleration is what hurts mpg.
But where are you getting the 50 mpg figure from?
 

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Greetings,

I'm not sure where you got the impression that a Volt gets 50 MPG while running on gas at that speed but I don't think you'll see that happen often.

I've achieved in the mid-40s on gas at much lower speeds (level with wide-spaced lights @ 30-35 MPH w/cruise) but even at highway speeds of 70, the best I've gotten are numbers is in the 40-ish range on level ground. I don't often have the advantage of level ground, so it's hard for me to pinpoint when that happens.
 

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I drove from Los Angeles to San Francisco on I5 with my cruise control set to 72 and the AC on eco at med/high fan speed. My MPG was 42.3 mpg for the trip.
 

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You're not going to see 50 MPG unless you're going downhill coming down a mountain -- then it's easy -- but 35 MPG seems a bit low. I routinely get low 40s going 62-64 MPH when using cruise. A consistent speed helps because it allows the smaller motor to drive a bigger gear. I suspect you'll get better MPG as your engine gets broken in. Owning a Volt for a week will not put the same number of miles on the engine as you'd get owning a regular car for a week.

FYI the AC makes a difference when running in CD Mode but very little when running in CS (ICE) Mode.
 

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Always make sure your tires are inflated fully. You'll want them around 40psi, but sometimes the dealers only put 32psi in for whatever reason.

When people report 50mpg in extended trips, it is usually the result of adding in the electric miles too. On my long trips I see the Volt get as good as 40mpg on the engine (though not always) but when factoring in the electric miles, it works out to more like 45mpg which is pretty decent.

Remember, you'll care most about lifetime MPG. An occasional trip might be at 40mpg, but if your lifetime MPG is at 80 or higher, the Volt is overall superior to anything else out there that can take you on a long trip.
 

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Engine break in will improve MPG over some time.
Tire pressure may help too (I drive at 42-45psi)

Was it raining, that also greatly decreases efficiency

Did you have "auto" defrost or anything on, that will suck extra energy if the defrost cycles on (it uses both AC and heat)


While i have hit 50mpg_cs many days, my lifetime average is 37. Cold starts are harder on milage and my engine, approaching 2500 ICE miles is probably still not quite broken in (I'm still on the original oil too).
 

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Interesting bit about ac use affecting efficiency differently in cs and cd modes, Don. I am at 89% electric but when i am using the genset i will crank the ac on comfort. Not because eco doesn't do the job, but just because i can!
:)
Other than the day i brought her home, my volt seldom goes more than 30 miles on the genset.



You're not going to see 50 MPG unless you're going downhill coming down a mountain -- then it's easy -- but 35 MPG seems a bit low. I routinely get low 40s going 62-64 MPH when using cruise. A consistent speed helps because it allows the smaller motor to drive a bigger gear. I suspect you'll get better MPG as your engine gets broken in. Owning a Volt for a week will not put the same number of miles on the engine as you'd get owning a regular car for a week.

FYI the AC makes a difference when running in CD Mode but very little when running in CS (ICE) Mode.
 

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Interesting bit about ac use affecting efficiency differently in cs and cd modes, Don. I am at 89% electric but when i am using the genset i will crank the ac on comfort. Not because eco doesn't do the job, but just because i can!
:)
Other than the day i brought her home, my volt seldom goes more than 30 miles on the genset.
I dunno Ziv, be careful about that. ;)

I think it affects range the same amount, it's just not as noticeable. Maybe I'm wrong though, but the A/C uses the same amount of electricity either way, and the genset is making that electricity.

In electric mode you're measuring a finite amount of miles, and in gas mode you're looking at Miles per gallon. The latter measurement looks less drastic, but should have the same decrease.
 

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Physics is physics. You can't run the A/C using less energy. It actually uses MORE energy when on gas because of conversion losses. You just don't see it because the scale is an order of magnitude different. (Kw vs gallons).
 

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Cruising at 70 mph on FLAT ground, I'd expect ~38mpg. Maybe 40mpg.

The trip there was on a back road in mountain mode (It is a hilly back road).
To clarify, Mountain Mode is not for "hilly" roads where you're going up and down. It's for ascending mountains. If you're just going up and down moderately sized hills, if anything it will hurt your efficiency somewhat.
 

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50 MPG sounds unreasonably high. For my trips using the ICE on highways, the best I have done is low to mid 40's. Here are some thoughts to consider.

35 sounds pretty typical, especially for a new engine. This will improve a bit once the engine is broken in. I seem to remember being 4-5 MPG lower initially compared to where I am now.

If the drive is hilly, that might explain a lot. If driving in L with the cruise on, you will get some regen on the downhills, but in Hold/Mountain mode, the ICE will be asked to run (maybe even run at a higher RPM) just to maintain the battery SOC. Terrain makes a lot of differance.

Make sure your tires are at 40-42 PSI.
 

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Interesting bit about ac use affecting efficiency differently in cs and cd modes, Don. I am at 89% electric but when i am using the genset i will crank the ac on comfort. Not because eco doesn't do the job, but just because i can!
:)
Other than the day i brought her home, my volt seldom goes more than 30 miles on the genset.
Makes perfect sense to me. When you're using the ICE the accessory losses are larger but, because the drive train losses dwarf most everything, the losses are a smaller percentage of the overall losses.

For an car being driven by an ICE the big factor is mass followed by aerodynamics and then rolling resistance. Most everything else is a rounding error. For an EV the biggest factor is aerodynamics followed by accessory losses followed by mass and rolling resistance. Going from an ICE to an EV, accessory loads like heating and cooling move from not being on the chart into second.

30 MPG on the genset seems very low. My Voltstats average is 37.36 but that's because MM doesn't do much for average MPG. On the road I don't think I've ever gotten less than 40 MPG and all those miles would be freeway miles.
 

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It's way too early for you to condemn your Volt for low mileage. And your mileage sample is too small to tell you much. Wait and do some trips that require an entire tankful or more and also do longhand calculations based on several fill-ups to verify the dash readouts. (yes, there will be some variation, depending upon how full you fill the tank) Also, a strong headwind is enough to account for your reported mileage at 70 mph. I found the difference on long trip mileage between a steady 65 and 72 to be about 1.5 mpg, with 40 mpg the mean. After a few months you will learn what works best to max out mileage in the Volt. Enjoy.
 

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Funny thing is that if you complain about getting only 35 MPG to almost any ICE owner in this country, they are going to be jealous. I owned a 2010 Prius, and at 70 MPH it would get about 45MPG hwy, I also owned a 2012 PriusC and that would only get me about 42MPG Hwy at the same speed. My Volt is getting about 40MPG in Charge sustaining mode at 70MPH on a flat highway. and with the electric miles figured in overall was high 40's. That being said I am at 120MPG Lifetime, and that climbs almost every day.
 

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...An occasional trip might be at 40mpg, but if your lifetime MPG is at 80 or higher, the Volt is overall superior to anything else out there that can take you on a long trip.
+1 - My first week with the Volt had me driving over 1300 miles, mostly on ICE. Four weeks later, I'm over 70 MPG with my EV usage at only 50%. Believe me, if you are driving mostly EV with the occasional ICE, the 36 MPG you get on ICE won't even be an issue.
 
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