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Proud owner of a new 2012 volt. On the way home from the dealer, I noticed I was only getting 29.3 mpg in CS mode only (Interstate all the way home- cruise set to 73). I charged the battery fully today, and did intermittent charging during the day. However, I noticed that the MPG still seems a bit low. I drove about 50/50 city/highway, yet I only got 41.4 MPG total, with 43 miles on the battery and 72.4 miles on the ICE. This seems a little low compared to others.... I made sure to fill it with 91 octane fuel and I filled the tires to 40 PSI. Granted, it is only 5 degrees here, but the climate was set to 70 degrees and ECO mode (I did precondition). Are there any suggestions to improve CS MPG?? Doing a little math, it looks like I got around 26 mpg when using the engine..... any help is greatly appreciated!!


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Mine has a lifetime CS average at about 29.6 of which approximately 75% of the total mileage is gas miles. I believe the PO had a pretty heavy foot as the lifetime mpg was 37. I did notice a slight boost after replacing plugs and oil change with approximately 74K on the engine, and had original plugs. What sort of mileage do you have on the car? What is the lifetime MPG? I know the MPG suffers a bit on city vs sustained highway driving. Cold weather, and cold engine also impact mileage greatly. I know in the mornings here with temps in the upper 30's/lower 40's I can see as low as an estimated 16 mpg when on engine alone. On long drives I can get a calculated gas MPG of about 40-43 also sustaining about 70mph. This is on a 2013.
 

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What brand of tires are on the car? Any tire other than the OEM Goodyears with the GM TPC 1406 will have higher rolling resistance. Check the CS mpg after the engine is well warmed up. My 2011 has Michelin Primacy MXV4's in 94V these tires have a 7.3" tread width compared to the Goodyears 6.9". MPG on the interstate highways at 75-77 mph varies of course, but generally 37 with a tail wind, 33 with a head wind. She has 91,500 on the odometer.
 

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What brand of tires are on the car? Any tire other than the OEM Goodyears with the GM TPC 1406 will have higher rolling resistance. Check the CS mpg after the engine is well warmed up. My 2011 has Michelin Primacy MXV4's in 94V these tires have a 7.3" tread width compared to the Goodyears 6.9". MPG on the interstate highways at 75-77 mph varies of course, but generally 37 with a tail wind, 33 with a head wind. She has 91,500 on the odometer.
Those Goodyear assurance tires come in 3 different tread widths for the same size of tire, a 6.x", 7.x", and 8.x" (don't recall the exact decimals, but they appear when you compare tires on tirerack.com). My car came from the factory with three 7.x" and one 8.x" tire as it must have been manufactured just as they were switching between styles. The 8.x" tire wore much slower than the 7.x" ones.

Back to the OP's question, driving 73 mph is your MPG killer for sure. If you slow down to 55 mph, you'll see your MPG climb, though depending on where you live, you might get killed in the process. When I was playing the EV range and MPG game, I found country roads where you could safely drive 50-55 mph and it was a shorter route pulling a mile or two off my commute. But then I said screw it, slapped on some cool looking 18" rims and deeper treadded tires for great traction, and drive like Jeff Gordon instead of like a grandpa taking on pony cars and ricer boys at any stop light. This car is a whole lot of fun when you aren't worried about fuel economy, and my 65 mile round trip commute is still netting me 70 MPG on the dash (driving like a grandpa with LRR tires would get me 90-100 MPG).

So slow down, it goes farther.
 

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I think the temperature is also having a big play too. The ICE (or any ICE for that matter) doesn't get very good mileage till it's warmed up and at 5F it will probably take about 30mins to get up to operating temperature. Also at that temperature you will have some ERDTT thrown in which will also skew your economy numbers.

I'm surprised you got as high as 43 miles on the battery at 5F (even with ERDTT running). Of coarse as others stated with speed thrown in that also will ding your economy a lot. Under those conditions any car would get horrendous millage.
 

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I recently acquired a 2013 myself and it seems in-line with what I am seeing. I'm doing much of the same stuff, 40 psi, etc, but certainly don't have to deal with 5°.... have it ever reached that in middle of Alabama?

First, I don't count the charge sustaining MPG when the engine just kicks in for a few minutes. Thursday I was running a bunch of errands getting ready for oral surgery the next day and ran out of battery 1.6 miles from home. I bet that "trip" returned well less than 20 mpg because the first minute or so was, the ICE was using more fuel until it gets warmed up.

I take a frequent East-West road trip across Alabama. In nice temperatures, 60's and 70's, minimal climate control, I'm only seeing 27 or 28 mpg with a mix of speeds ranging from a 50 mile leg at 70 mph to a bunch at 55 mph.

The last trip, I avoided the Interstate leg and took the two-lane. It was a nice day in the upper 60s and enjoyed the leisurely drive. I pulled out of my driveway and drove five miles on battery. When I reached 55 mph, switched to Hold mode, waited about a mile and then reset Trip B. 165-ish miles later, nearly 100% at 55 mpg and having only driven through 4 small towns (only two big enough for traffic lights,) I arrived at my destination town when I switched back to battery for the remainder of the drive. Trip B was reporting 28.6 MPG which was near a record for me.

However factoring in another 20 miles on battery that day and another errand, I easily exceeded 30 MPG overall for the "tanks."

(My 4WD Silverado on that exact same drive one week later with similar weather conditions returns 23.8 MPG resetting the drivers information center at the same spot and checking at the destination city limits. My 2013 Malibu was always around 41 mpg for the entire trip, regardless of the exact route.)

Anyhow, I, too, wished my mileage on gas was better on the Volt and that it didn't require premium unleaded, here often 60 to 80 cents per gallon more than regular, but I have to remember that I have driven over 600 miles without gas at all made a tank of gas last over 1000 miles. In the end, I am driving 600+ miles per month on electric and keeping even more of this miles off my truck which I love.... despite only getting 16-18 mpg around town.

That said, I agree. When your weather warms, the engine will use less warming up, warmer air is less dense and thus has lower resistance, you'll need less power for climate control (although once the ICE warms up, you'll have plenty of heat) and you'll lose the winter blend of fuel. It sounds like you'll do just fine in a few months.

Now I need to go outside and check on my tomatoes. We're suppose to have a cold snap here and get into the 30s... (grin)
 

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30 MPG is my normal MPGcs in winter in Wisconsin. I rarely drive faster than about 65-68, though. Once the temps are above 50F, it'll be 40 MPGcs, and 45+ at above 70F.
 

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I've done way too many long distance road trips in my 2012 - back and forth from New York to Tennessee. With the OEM tires, at 72 mph average, I would get maybe ~40 mpg, depending on weather/traffic. I switched to Continental True Contacts back in November, and have made that long drive twice since then, and it's knocked about 2 mpg off, so I'm getting 38 mpg average at 72 mph average.
 

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Discussion Starter #10
30 MPG is my normal MPGcs in winter in Wisconsin. I rarely drive faster than about 65-68, though. Once the temps are above 50F, it'll be 40 MPGcs, and 45+ at above 70F.
I just took it on a road trip to Chicago! I definitely noticed the change from 5 degrees to 35 made a huge impact on mileage.....


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Cold weather has an effect on all vehicles, gas, diesel, or electric. Our 2010 Prius is averaging 42-45 mpg, winter driving, 55 mpg is the norm in summer. Gasoline is also blended for winter use which has less BTU's per gallon, which means less heat energy per gallon.

Our 2014 Volt the last trip in the summer when we drove it to Wilsonville Chevrolet to purchase our new 2016 Volt, averaged well over 40 mpg just on gas, 87 octane at that.
 

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Another factor to consider is trip length. If you are making most of your trip on battery and only running the gas engine for a short time at the end, then a lot of the energy is going into warming up the engine and you get poor efficiency for those runs.

I personally have trouble getting more than 30-32 MPG if any negative factors exist such as short engine runs, city driving, speeds over 75 MPH, hills, rain, etc. I think my vehicle's lifetime is 36, and it is only that high because most of my CS driving is on long interstate highway trips.
 
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