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I drove my new 2018 Chevy Volt today for a longer trip than normal. In particular, I drove it for about 200 km. The first 95 km (approx.) was completely driven using EV. I let the charge drop to zero to see how the gasoline engine would perform. I was disappointed to find that I used about 6.8 liters for the final 100 km. which seems high.

Is that the sort of engine efficiency that I can expect from the Volt? What are other people's experiences?
Thanks.
 

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You need to give the engine time to warm up sufficiently. A good portion of your 100km probably didn’t have the engine up to optimal temps yet.
 

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How fast were you driving, and what were the outside temperatures? It looks like you're in Ontario, meaning it was probably in the 30s or 40s (*F). Your fuel consumption equates to around 35 MPG, which is what I normally get in the winter on the highway. It's a symptom of the cold weather and the drivetrain being tuned for lower speeds, not highway speeds (I typically drive 75-85 MPH on the highway).
 

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Cold, speed, road conditions, etc. will have an effect on your gas mpg's as well as your electric range. Our last trip just on gas for 143.5 miles, was over 46.5 mpg, with temps in the mid 40's or so. This was with our 2016 Volt which is approaching 30,000 miles with 8,000 miles just on gas. Your Volt should also improve on mpg's with the gas engine when it breaks in after a few thousand miles or so....
 

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Seems low, but not much of a sample. You lose MPG if you have the heater on "max". On my first trip when car was brand-new, I drove to Buffalo in March 2017 and got about 38MPG on just gas. Though that was very low. Wife wanted car on "max" heat. Later on longer trips I always use "eco" setting and on gas alone I always get 45-49MPG on gas-only (hold mode). I don't worry about all those combined gas-electric or electric-equivalent mileage things as they are convoluted estimates anyway. I look at real KwH use and real gas use.
 

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Seems low, but not much of a sample. You lose MPG if you have the heater on "max". On my first trip when car was brand-new, I drove to Buffalo in March 2017 and got about 38MPG on just gas. Though that was very low. Wife wanted car on "max" heat. Later on longer trips I always use "eco" setting and on gas alone I always get 45-49MPG on gas-only (hold mode). I don't worry about all those combined gas-electric or electric-equivalent mileage things as they are convoluted estimates anyway. I look at real KwH use and real gas use.
The heater has a huge impact on the battery, but should have negligible impact on the engine. The engine usually prefers to be cooled somewhat by having heat drawn off of it.
 

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Seems low, but not much of a sample. You lose MPG if you have the heater on "max". On my first trip when car was brand-new, I drove to Buffalo in March 2017 and got about 38MPG on just gas. Though that was very low. Wife wanted car on "max" heat. Later on longer trips I always use "eco" setting and on gas alone I always get 45-49MPG on gas-only (hold mode). I don't worry about all those combined gas-electric or electric-equivalent mileage things as they are convoluted estimates anyway. I look at real KwH use and real gas use.
The heater has a huge impact on the battery, but should have negligible impact on the engine. The engine usually prefers to be cooled somewhat by having heat drawn off of it.
Gas engines are thermal devices. Heat is used to expand the air in the cylinder to move the piston. If the engine is not up to operating temperature the engine will not be as efficient. Not all the heat that the coolant would draw off the engine is waste heat. So running the heater hard does draw some usable heat off the engine decreasing efficiency. Gas engines typically use 15% more energy in cold weather.
 

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I get 6 l/100km at 125 kph and 20C. Yes, cold and rainy weather will lessen mileage. Take a few more drives to determine if there is a problem. Tire pressure 2.7 bar? Engine temp is selectable on the driver screen. Should be around 90 C. Do the rear wheels heat up after a highway run? Could be a sticking parking brake. After a highway run, stop, leave the car on and open the hood. This will start the engine. Engine should run smooth with no "coughs" or misfires. Are all the fluids correct? Oil and 3 coolant reservoirs?
 

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My new 2017 (3 months old) was getting disappointing mileage. In fact, only until just recently did I start to notice an increase to the advertised efficiency. I believe it is because the ICE is now getting sufficiently "broken in." Unlike the Gen 1, the Gen 2 has all its range extended modes mechanically connected in some form and the transmission really needs loosening up. My ICE seems slowly getting "smoother" as well (had all kinds of weird vibrations and "chuggle-lite" symptoms). I didn't start noticing this until I reached about 1000 miles (1600 kilometers) on ICE. I hope it continues to get better because so far I'm a bit underwhelmed with the Gen 2 ICE performance overall--but the jury is still out.
 

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Stonegate Volt

I get about 5L/100KM (58MPG) with my 2017 using the ICE mostly on occasional extended highway trips. Seems reasonable for the small amount of time I need it (88% on battery so far).
 

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Fellow Ontario Volt driver here. I'm also disappointed with the gas motor economy. On the motor the volt is quite a bit worse than my previous car (2009 Honda Fit) at 120km/hr. I drive the 401/407 from Waterloo to the 400/407 area all the time. It seems like the gas mileage tanks harder at high speeds in the volt than other gas cars i've had ( Skyactiv Mazda, Honda Civic Hybrid, Honda Fit, Diesel Jetta). I had a VW Tiguan too, it was worse than the volt but didn't dive so hard at higher speeds.

On a brighter note, since I can charge at work my average economy is about 3L/100km (about 120km each way). No regular car can touch that. I do have days of regret though not getting Civic Touring.

If I baby it on the motor I get 5L/100km, but I can't drive like that on 401 during commuting. So it's usually over 6L/100km for the gas portions. I seen high 6's a number of times.
 

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Have driven that stretch many times and during summer I get about 5.2 @ 115 km/ hr.( driving against traffic when I go on it) Cooler temps seem to reduce this when they switch to winter gas ( Google winter gas impacts). Also depends on what gas you use, I was averaging just over 5 on drive to Florida few weeks ago until I got some gas at a Valero station ( still Top Tier gas) and mileage instantly dropped to 6.5. Mileage went back up upon next fill up. Also make sure you are using Top Tier gas (Google it and you will find big difference in cheaper gas specs). Also how do you drive 120 on that road, it’s usually so congested that you are lucky to drive 40 during the morning/afternoon/night rush hours. Maybe easier to say 24/7 rush hour. LOL.
Fellow Ontario Volt driver here. I'm also disappointed with the gas motor economy. On the motor the volt is quite a bit worse than my previous car (2009 Honda Fit) at 120km/hr. I drive the 401/407 from Waterloo to the 400/407 area all the time. It seems like the gas mileage tanks harder at high speeds in the volt than other gas cars i've had ( Skyactiv Mazda, Honda Civic Hybrid, Honda Fit, Diesel Jetta). I had a VW Tiguan too, it was worse than the volt but didn't dive so hard at higher speeds.

On a brighter note, since I can charge at work my average economy is about 3L/100km (about 120km each way). No regular car can touch that. I do have days of regret though not getting Civic Touring.

If I baby it on the motor I get 5L/100km, but I can't drive like that on 401 during commuting. So it's usually over 6L/100km for the gas portions. I seen high 6's a number of times.
 

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My new 2017 (3 months old) was getting disappointing mileage. In fact, only until just recently did I start to notice an increase to the advertised efficiency. I believe it is because the ICE is now getting sufficiently "broken in."
My gen2 is at 11 months with gas ICE mileage slowly creeping up. The last 6 month averaged 45-46 mpg ICE, except I only had 220 ICE miles so I'm not using the engine usage. For the 1st 5 months, I averaged 39-40mpg but that included an interstate trip with 70-80mph driving. My opinion is that ICE mpg improves by 10% as the car lossens up, and EV mpge also improves. I think maybe the tires have to break in too.
 

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Gas engines are thermal devices. Heat is used to expand the air in the cylinder to move the piston. If the engine is not up to operating temperature the engine will not be as efficient. Not all the heat that the coolant would draw off the engine is waste heat. So running the heater hard does draw some usable heat off the engine decreasing efficiency. Gas engines typically use 15% more energy in cold weather.
I don't see how the heater can increase the engine load, unless the coolant temperature is below the thermostat setting. Otherwise, it's just a master of where the heat goes.
 

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Are your tires properly inflated? Most of us run 2-3 psi over the manufacturer recommendation to increase efficiency. With temps in the 40's and my tires at 40psi, my 2016 was getting right at 45mpg on gas on a recent hwy trip. Using the stock Michelin Energy Saver's.
 
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