GM Volt Forum banner

1 - 20 of 21 Posts

·
Registered
Joined
·
45 Posts
Discussion Starter #1
What effect does stop and go have on range? How big a hit are headlights and A/C? My better half commutes 28.25 miles one way to work, about 16.5 miles on the Beltway and the rest surface roads. She goes early enough the speeds are fairly consistent 65mph in the morning. In the afternoon 5-6 miles on the Beltway are creep along. She might be able to 110 charge at work but it isn't certain so I'm curious roughly when on the way home to think the ICE would kick in.
 

·
Registered
Joined
·
205 Posts
When the Volt is stopped, there is no expenditure of energy, which is different from an ICE car which continues to idle the engine when stopped. This is the very reason that an ICE car is so inefficient. It is most inefficient when stopped. An electric car is most efficient when stopped, using very little (virtually none) when stopped. Of course, as you point out, when running lights and A/C there is a slight draw on power, but it is negligible compared to the energy required to propel the car down the road at 65 mph. So your wife will use the most energy during her morning drive and a lot less during the slower stop and go drive in the evening.

In addition to my Volt, I own two(2) all-electric cars. If I try to travel too far, I know I can increase my range by doing two things....slow down and turn off climate control. The first one (slow down) has the largest effect on range, which is the very thing you describe with the stop and go driving. When I drive the Volt, I'm not as concerned since I have the engine back-up.
 

·
Registered
Joined
·
2,130 Posts
What effect does stop and go have on range? How big a hit are headlights and A/C? My better half commutes 28.25 miles one way to work, about 16.5 miles on the Beltway and the rest surface roads. She goes early enough the speeds are fairly consistent 65mph in the morning. In the afternoon 5-6 miles on the Beltway are creep along. She might be able to 110 charge at work but it isn't certain so I'm curious roughly when on the way home to think the ICE would kick in.
Rush hour helps range (slower speeds, etc)
 

·
Registered
Joined
·
2,634 Posts
The Volt has maybe 750 watts parasitic draw at idle (guessing, haven't measured it and depends on active accessories). This draw might amount to 3 miles range per hour. The AC might draw up to 3 kw and the heater up to 7 or 8 kw, or about 11 miles range per hour for AC and maybe 25 miles range per hour for max heat (based on EPA rating, not guessometer which will figure in climate use to some extent). 30 minutes of max heat might drain 3 or 4 kwh from the battery. 30 minutes of max AC maybe 1.5 or 2 kwh. These are close to worst case.

Given houston, winter range might be better than summer range (an exception, heater and cold temps kill range). I would guess in months where heater isn't required and neither AC she could make the drive with no gas (have to watch max speed), and maybe in the summer 1 hour of AC use might reduce range by 10-15 miles or so, will depend on settings of course. Any speed over 60 mph starts to eat into range quickly.
 

·
Registered
Joined
·
1,890 Posts
As Joe said, driving in stop-and-go traffic is less energy intensive than highway cruising.

Headlights are negligible.

Depending on how hot and sunny it is, your climate settings, driving situation, etc., I'd guesstimate that A/C might account for 2-10% energy used. It very much depends on a lot of factors. But it's not typically a big drag on efficiency.
 

·
Registered
Joined
·
13,556 Posts
The thing that will affect the mileage the most is the 65mph in the morning and when temps drop to near freezing and the battery turns of the onboard electric heater to warm itself (seven if you turn off cabin heat). Stop and go rush hour traffic is the perfect situation to go a long way on little energy and regen when slowing. I spent 2 years taking an alternate route that was shorter and slower to get close to 50 miles of range in ideal conditions on my volt rated for 38 miles. But after the allure and games wore off, I've switched to new custom wheels and better traction tires and stopped driving like a grandpa - going 70 mph on the interstate. Range has dropped significantly, but I'm enjoying the car more and getting places sooner.
 

·
Registered
Joined
·
3,634 Posts
It's less of an energy hit than a ICE car takes. The headlights are about 110 watts. The HVAC can be something over 3kw peak but is not likely to be running 100% duty just sitting there.
 

·
Registered
Joined
·
1,205 Posts
It will affect mileage more so if the car was just started and hits stop and go vs driving for a while and hitting stop and go traffic. The colder it is outside, the worse the effect as the battery and cabin may require some energy to warm up. My worst range is in winter when in stop and go traffic when I first get in the car. If you are in the south, the impact will be much less than in the north.

Essentially, if you are using energy and not moving, your mileage is going down, which is the case in any car. When warm out, EV's have an advantage. When cold out, not as much.
 

·
Registered
Joined
·
23 Posts
All good commentary preceding mine here: Bursts of hard acceleration and sustained high speeds (over ~60-65) may be the biggest factors on what I think you're describing -- similar to my DC area commute, which is just under 58 miles roundtrip. I regularly make it on battery only.

If traffic is light & moving very fast, I might need to run on ICE for a few miles at most (I'm not going to imped traffic). If it's congested & slow, I'll get home with a few EV miles to spare.

70+ highway speeds will eat range -- even for a slippery car like the Volt (or Tesla, etc.). As will numerous hard/max accelerations to merge or pass -- a few are no problem (and it's nice that our economy car is capable of good acceleration) -- but a lot will reduce range noticeably.

Note, I've done several 400+ mile road trips, Normal EV mode on each end and Hold mode for high speed highway (including up & down East coast mountains at 70+). The Volt does great and has no problem keeping up with traffic (and passing when needed). And with good overall mileage. So, I've gotten a practical feel for effects of speed and traffic.

With a little experience you'll figure out how to maximize range. If you can add a few miles of range at work -- as long as you're not paying too much for that (i.e., more than the price of gas) -- you should be close to a battery-only commute! And if you have to use a little gas, that's OK :^)
 

·
Registered
Joined
·
926 Posts
What effect does stop and go have on range? How big a hit are headlights and A/C? My better half commutes 28.25 miles one way to work, about 16.5 miles on the Beltway and the rest surface roads. She goes early enough the speeds are fairly consistent 65mph in the morning. In the afternoon 5-6 miles on the Beltway are creep along. She might be able to 110 charge at work but it isn't certain so I'm curious roughly when on the way home to think the ICE would kick in.
Are there any notable hills during the surface streets portion? That's usually what limits my range to 53 miles EV every day and I have a roughly 36-mile one-way commute. I used gas for roughly the last 15 miles of my commute.

When I had a 32-mile one-way commute, it surprisingly led me through flat surface streets and os I could make the trip completely on electric. Though, this was back in late August where it was not too hot and I could run the Volt without HVAC and the weather was conducive to EV mode (warm and dry).

On the one day I broke 72 miles EV, that was on this same 32-mile one-way commute. Traffic and detours forced me to enter neighborhoods I wasn't familiar with. So I got lost for another 10 miles before getting home. Apparently, construction happens at the same time I was taking a "relaxing" evening drive, along with a stadium event. So I can attest that stop-n-go did wonders for my range in flat city traffic.
 

·
Registered
Joined
·
125 Posts
my experience:

every 1 min delay = 0.1 kWh energy saving.

So if I am lated by 10 min due to traffic, I can save about 1kWh (or gain about 4-5 miles range).
 

·
Registered
Joined
·
45 Posts
Discussion Starter #12
If a couple of fairly significant freeway overpasses count then there are notable hills. Otherwise no. It's Houston so pretty much flat.
 

·
Registered
Joined
·
244 Posts
Last week I was stuck in an expressway jam, and it took 45 minutes to travel three miles. My estimated range only dropped two miles. No AC though.
 

·
Registered
Joined
·
45 Posts
Discussion Starter #14
AC is pretty much mandatory around Houston for the majority of the year. Heat not so much.
 

·
Registered
Joined
·
247 Posts
For me, stop and go traffic, with proper use of the paddles, has a large positive impact on range due to the regenerative breaking.
 

·
Registered
Joined
·
1,488 Posts
stop and go traffic with only the fan on can improve the range.

I go to work very early in the morning, about 6 am, and the temperature dips further down until 1 hour after sunrise. So I put on hold mode for the entire freeway section of the trip, at 70 mph and comfortable 75 deg F setting. Then switch to normal after hitting the exit, switch to fan only and drive ten miles more to the office along business roads. Then on the way back, when it is warmer, and having more traffic, I drive in normal electric mode and then fan only, all the way home, consuming the entire battery energy, and it would hang in there until I reached my home base charging station. Doesn't affect my CS mode 45 mpg, but I had very good electric, 60-64 miles to the entire 14.1 kWH or about 4.25-4.53 miles per kWH.
 

·
Registered
Joined
·
1,488 Posts
stop and go traffic with only the fan on can improve the range.

I go to work very early in the morning, about 6 am, and the temperature dips further down until 1 hour after sunrise. So I put on hold mode for the entire freeway section of the trip, at 70 mph and comfortable 75 deg F setting. Then switch to normal after hitting the exit, switch to fan only and drive ten miles more to the office along business roads. Then on the way back, when it is warmer, and having more traffic, I drive in normal electric mode and then fan only, all the way home, consuming the entire battery energy, and it would hang in there until I reached my home base charging station. Doesn't affect my CS mode 45 mpg, but I had very good electric, 60-64 miles to the entire 14.1 kWH or about 4.25-4.53 miles per kWH.
I wish the next generation Volt would allow you an option for 100 mile battery range, then I wouldn't use any of the hypermiling tricks. I just wanted to drive comfortably without much fiddling, since my electricity is practically free. Would be willing to dole out $5,000 more for the additional battery range rather than buy a separate EV.
 

·
Registered
Joined
·
3,536 Posts
100+ deg day in Dallas with full on sun light you will fight a large heat load -- hot road and NO wind cooling when not moving.

the SUN will make it hotter than the out side air temp - and good window tint will help a LOT

Solar energy at work and NOT the way we want :)

----
At least with the VOLT - I don't have to turn on the HEATER to cool the car when stuck in Dallas traffic as I did with my old car.
 

·
Registered
Joined
·
13,556 Posts
I wish the next generation Volt would allow you an option for 100 mile battery range, then I wouldn't use any of the hypermiling tricks. I just wanted to drive comfortably without much fiddling, since my electricity is practically free. Would be willing to dole out $5,000 more for the additional battery range rather than buy a separate EV.
Same here. Tesla offers options for different sized batteries, why can't GM do the same? Plus dealer installable upgrades would also be awesome.
 

·
Registered
Joined
·
1,003 Posts
Same here. Tesla offers options for different sized batteries, why can't GM do the same? Plus dealer installable upgrades would also be awesome.
I think it is because Chevy has shoehorned as much capacity as they can into the "T" shaped form factor. How many of you would give up half of the cargo capacity for more range? With the average american driving 40 miles a day or less they have concluded (rightly or wrongly) that not enough people would trade cargo carrying capacity for more range to make the development costs worth their while.

Keith
 
1 - 20 of 21 Posts
Top