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Chevy Volt watts per mile vs. Model S

I presently own a 2012 Volt and have an order in for a Model S. I've been curious about the range people are getting in the Model S. In my Volt I can routinely get 41 or 42 miles from the 9.7Kw of battery it lets me use which means 230 watts per mile. Obviously this range is this time of year which means nice warm weather which helps. Getting this range doesn't feel like I am hypermiling or babying it. I run the AC on Eco mode, I run it on normal not sport (but can easily beat 300 watts per mile even in sport mode). I realize the Model S is a much larger and more powerful car, but if you got the same efficiency from an 85Kw Model S you could go 369 miles. It seems like 300 miles on a range charge should be pretty easily doable and even possible on a 90% charge. You might even be able to get the EPA estimated 265 out of an 80% charge. Any Model S owners out there that are prior Volt owners have any experience to share?

It's very hard to get watts per mile for Volt since it's a plug in hybrid and not pure EV. I have heard from some auto test reviews the gasoline engine does turn on when additional acceleration is needed even during the initial 40 miles EV mode.

Over at Tesla Motor Clib there is a thread lifetime Wh per mile., that gives a good range what to expect. My lifetime average for 6k miles is 335 Wh / m... but that includes a lot of city, on longer trips I can easily get it under 300 Wh / m driving 72-75 m/hr

Carlk, no I am sorry, you are wrong. Volt does not use the engine at all for added acceleration. It can use the battery if you floor it from a stop to its max speed of 101 mph.

It only uses gas when the battery charge reaches low state of charge, you enable mountain mode and SOC drops to 13-15 miles remaining or a 2013/2014 model uses its Hold mode (i will leave that to you to google).

Volt Wh / mile depends on how you drive. Same as tesla. Once up to speed, Wh/mile is similar. The speed you drive, ambient temps and a lot of other inputs alter the Wh/mile. I estimate on average, removing pre 5.0 firmware vampire drain, that a normal tesla usage is about 5%-10% more than a Volt. More on board electronics such as the sound system and dash electronics are part of that. The higher weight of the model S also is part of that.

Does it really matter? Yea, I also believe that if you extrapolate out the Volt's 10.4 to 10.8 kWh of usable SOC, could say have a 50kWh system give 200 miles of range but that would mean carrying a 60kWh battery to do that in a Volt. I suspect that the range charge of a Tesla uses far more of the battery State of Charge than Volt uses with the 10.4 to 10.8 out of the physical 16-16.5 capacity.

bTw, i also get well over 40 miles of range, and in summer, my morning commute to NJ gives me 50 miles electric range. I do lose 600 feet of elevation but all the miles are highway between 60-65 mph.

I've gone to a range of around 300 miles using slightly below 300 watt/hr. But it was driving like a grandpa conserving range avg 40-55mph on the freeway and drafting behind trucks.

No fun at all. I prefer driving at 400-500wh/mi and putting a smile on my face.

I also realized after I posted that all 85kw are probably not useable. It would be interesting to know how much of the battery capacity you can use before you hit reserve battery life, someone on this forum probably knows. In the Volt since you have the gas engine you can use all the battery they allow I'm guessing Tesla has certain parameters on battery usage to preserve long term battery life.

Some notes on units:

k = kilo = SI unit for 1000 (always lower case)
W = watt = energy use per time (always upper case)
h = hour

Wh = (energy per time) * (time) = energy
kWh = (energy per time) * (time) = 1000 more energy

Rember W is a rate of enery usage and Wh is total energy. So it is correct to talk about batter capacity in turms of Wh or kWh, but not W or kW.

Water analogy:

W is like gallons/second.
Wh is like number of gallons.

turms = terms (this forum could really use an edit capability)

I've got a little over 5000 miles on my S85 now. It's a daily driver for me at about 150-160 miles per day. Most of this is interstate between 70-75mph. I am averaging 305 Wh/m. I don't drive like a grandpa, but I'm not overly aggressive with it either.

I routinely charge to 90% ... start out at a "Rated" range of 237 and return home with about 75 miles remaining.

It's summer here now with an ambient between 80 and 90 ... and I don't find much difference between windows up/down, A/C on/off, etc.

YMMV

We have a Volt and a Tesla. We easily get 200 wh per mile around town in the Volt (5 mills per kWh) and struggle to get under 330?wh per mile (3 miles per kWh) in the Tesla. I think the difference is the additional 1000 pounds the Tesla weights. On the highway above 65 mph, I think the Tesla might be a bit more efficient. Speed doesn't seem to have as dramatic an effect with the Tesla as the Volt. It's accelerating the extra mass in the Tesla that hurts it in stop and go.

My Tesla, on same route as my Volt gives me 260 Wh/mi where 2011 Volt range was 46 mi. Hope that helps.

I have averaged 311 W/Mile since my Tesla was delivered (6,300 miles) and have averaged 288 W/mile over last 3,000 miles. Most of these miles are from in city driving, commuting to and from work 35 miles round trip @ 30-55 mph. From my perspective I find it very easy to beat the 300 W/mile rated range. It is wholly dependent on the way one drives, heavy foot or not. I do not drive my car hard but do not baby it either. I had an opportunity to drive a P85+ for 1.5 days while my S85 was being serviced, and had no problem getting under 300 W/mile.

@bonaire looks you're right. My bad.

@Motobones That should not be a surprise at all. Comparing Civic and S550 would get you even more drastic differences.

No, the Model S, being a bigger, heavier car, does use more juice per mile than the Volt.

But, how does the Volt compare on Watt-hours per mile per passenger?

Volt: 230 Wh/mi / 4 passengers = 57.5 Wh/mi/pass

Model S: 320 Wh/mi / 7 passengers = 45.7 Wh/mi/pass

Of course, I suspect the Leaf does even better than either of these cars on this metric.

The other metric that can be compared is MPGe where the Volt is 98 and the MS 60 is 95. Pretty similar mileage given the difference in performance and carrying capacity!

Volt weighs 3,781 lb, Tesla 4,647 lb, a good 20% extra weight.

CfOH, sure. Go person-efficiency on it :)

Most folks drive alone to work, so the idea of using energy per person mileage is not a typical situation.

What about a volt pulling a small trailer full of circus clowns?

@bonaire: Ah, very clever are you?

I see your tiny trailer of circus clowns and raise you a frunkful of midgets!

One interesting claim regarding the Volt: my brother says that the on board generator on his Volt will charge the battery at about 54 kW, the same rate as the high speed DC (CHAdeMO) chargers for the Leaf, etc. He says he needs to put the Volt in "mountain mode" to do this. I don't vouch for the reliability of this claim, and I don't contend that it is an efficient way to charge the battery.

Couple of things from our experience my weekly commute is about 187 miles each way. When I can I try to make the drive when the wind is favorable. At 70 to 75 it is very easy for us to make it each way on a standard charge with 50 to 80 miles range left. Most of the trip is at consumption of 260W to 300W with AC on. 290W to 320W with the heat on. Wish that Tesla had an inexpensive Air Speed meter. That would help gageing the projected juice use, and would give a better reading on how much drafting is helping range.

My brother has a Volt and lives on a busy four lane rural road. He says, and I have been with him when it happens, When he backs out of his drive and guns it to get out of the way of traffic, the ICE always starts, even just off the battery charger. Then he has to stop the Volt to get the ICE to shut-down.

Incidentally, I don't want Tesla to make the touch screen directional responsive. Then I would have to be driving up all the time. At least now, I'm driving down and can save juice half the time-------

Dr. Bob - no that is not how it works. I actually don't believe this is happening and you are making this up. I've studied the Volt for years, we have heard from Volt engineers regarding this and what you explain does not happen. The electric motors always draw power from the HV battery. The engine cannot "assist" acceleration. There are even Volt drag race vidoes online from a drag strip - can't push the car harder than that - no engine usage.

I have a Volt and a Tesla 40. If you are getting 41-42 miles from your Volt on the highway, you are probably driving at 60-65mph and will see about 260-270 wH/m in a Tesla. Non-highway driving varies greatly because of the extra 1000lbs in the Tesla. With mild temps and reasonable stop/starts, 41-42 miles from Volt AER will translate into 290-330wH/m. There is no way around the higher burn rate with stop/start driving and an extra 1000lbs.

Another consideration for energy usage in the Model S vs the Volt is the vampire losses when off. The Model S burns about 2kwh/day while turned off. There are lots of threads on this and more precise numbers. Tesla is also working to reduce these losses but it will be at the expense of responsiveness in the remote app and in starting (booting up) the car.

Dr. Bob Reinke - That is not accurate for normal Volt operation unless the battery is depleted. There are discrete situations that brings the engine in the Volt on and high power draw is not one of them. Depleted battery, extreme cold, gas burn after extended period of no engine use, Mountain Mode battery charge level is reached, maintenance mode induced by open hood, and Hold Mode are the ONLY events that trigger the engine.

DouglasR - The Volt's generator maxes out at that rate but only uses it when the algorithms dictate. Mountain Mode has more scenarios that dictate this level, particular if MM is initiated with the battery deleted below the MM threshold. Under most scenarios the algorithms more closely match the generator's rate to the "perceived" power demand. It doesn't/can't match instantaneous demand but rather user recent averages and real time inputs.

I can vouch for the fact that the Volt does not use the ICE at any point for acceleration unless the battery is depleted. The ICE does come on for me when the outside temp is 25 degrees F or less to help warm up the car, but it does not come on to aid acceleration. My experience is that the car accelerates better when the battery is fully charged and the car is in Sport mode, than when the battery is down and using the ICE.

Yea, A full battery will have a higher voltage and any EV should have a bit more "punch" when full than when the battery is depleted and/or the electric motor has heated up.

@DouglasR I don't think the claim is true. Charging at 54kW means the gasoline engine is capable of providing power to run the car more than 200 miles per hour. Way beyond what is possible.

Carlk, i think you are a bit mistaken here. A car accelerating from a stop uses far more than 54kw. That is only about 75hp. Where do you find your 200 mph idea from? It takes about 700hp or 550kw to make a car go 200mph (ie. Nascar type power)

@bonaire
You are misunderstanding his use of 200 MPH as a rate of speed rather than rate of charging the battery.

@carlk - How do you know 200 mph charging is way beyond what is possible? The Model S can provide up to 60 kW of regenerated power. Why couldn't the Volt provide 54 kW of generated power?

I don't know that it will sustain this high level of charging for very long. As I understand my brother's driving strategy, he uses mountain mode to increase his overall fuel efficiency on longer trips. He switches to mountain mode when the battery is partly depleted, which results in adding charge back to the battery before he arrives at his destination. He claims that the car charges up very quickly, and that his overall gas mileage is higher than when he uses normal mode.

Those of you who have a Volt can comment as to whether this makes sense. I'm only repeating what I've been told.


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