Electric Cars Continue to Make Inroads

The girls gave me an ultimatum: buy a manual transmission and do all the driving yourself. So, I got the automatic Audi.

Got to admit, a manual tranny now makes about as much sense as a mechanical adding machine. The no-torque-converter 6-speed dual-clutch thing is a morally acceptable surrender.

I got my left leg seriously bashed last week, at Squaw, when an idiot yahoo snowboarder traversed at speed, crashed, and jammed his board into the back of my leg just below the knee. But to drive my car, I don't need a left leg.

Turbocharging small engines is another scam. It reports great mileage when driven in granny mode, but the dynamics of a turbo encourage real people to drive in, well, turbo mode.

If I'm going to waste fuel, I may as well get some low-end torque too.

If you want low end torque, you need to go electric. They crush gasoline engines.

What size engine? Want to drag ?>:-} ...Jim Thompson

On Saturday, December 31, 2016 at 11:35:28 AM UTC-8, rickman wrote: ...

My time estimate is only approximate - but I have measurements for the tota l energy and distance that are probably within 5% - so yes I can run the ca r on an AVERAGE of < 5HP.

This is an example of my round trip commute (two trips of ~11mi). These a re shots of the energy screen in the car showing energy used and miles trav elled.

The energy used here is consistent with the energy required to recharge the car as measured by either the Chargepoint EVSE or a WattsUP power meter at home.

If each trip is ~30min (it often takes more) the average power is only 3.4k W or 4.5HP.

My average speed is only about 11mph (welcome to Silicon valley traffic!). What really reduces the average is the waiting time at stoplights, probabl y 50% or more of the time the car is not moving or creeping along in traffi c.

When an EV is stopped the power consumption is a few hundred W (maybe 400W if the lighting/heating/cooling is not needed). On the other hand my gasoli ne vehicle (Mazda3) consumes ~0.25 G/h when idling - which is the equivale nt of about 8kW.

Under good conditions on the same trip my gas car consumes about 0.7G of fu el for the same trip giving about 32mpg. Under bad conditions (cold weather , heavier traffic the consumption is significantly more).

Agreed in the steady state it only takes about 1-2kW to keep the car at an acceptable temperature - but when starting the trip the car is cold and the heater is on full for quite a few minutes - the heater is also used to kee p the battery in a good range. The battery in even a small EV such as the Spark EV has about 600 lbs of mass - that can take a lot of heat to bring u p to temperature - in Silicon Valley it was rare for the battery heating to be needed.

One of the linked photos shows the use of energy for heating and battery co nditioning - they are zero in that example but I have seen them at about 30 % of the total energy.

A particular problem I found in the Spark EV in cold rainy weather is that it was difficult to keep the windscreen and side windows clear of moisture

- I would need to keep the heating going for longer than required for comfo rt, just to ensure visibility. From that aspect a gas car is much better t han an EV in winter, the free heat is extremely valuable. I drove a Tesla Model S for a while and that was not so much of a problem.

The A/C also needs 1-2kW for steady state consumption but again getting int o a hot car requires several minutes of full power operation in hot weather - i.e. a significant portion of the trip if that is only 20-30 minutes. C ars do not have very good thermal insulation.

A gasoline car uses fuel when standing stationery and gets zero MPG - if th e driving profile does not match the EPA standard then YMMV.

kevin

Define "not being able to afford...". You don't think they can afford it?

Do some leasese have non-zero equity?

When EV's take off? When will that be? ...and how does this affect current leases at all?

What do EVs have to do with leases?

Does what other people do really bother you?

Have another cup (or bottle, or whatever). ;)

Which engine? Ours doesn't have nearly that difference (not even the

Of course. If you have a lead foot, you won't get the same milage as someone who is much more conservative. Pealing rubber doesn't just increase the cost of tires.

We agree.

My F150 gets 16-18 MPG, depending on season, and maybe 18-19 on the open road. ;-)

Saving 25%, or even 50% of my gasoline budget isn't of any importance. Gasoline is a great thing. It's *freedom*.

They could but they'd have to supply six wires (compatibility). It's uneconomical.

Right, here it's 2x120V phase to neurtal. If they supplied three-phase, they'd have to supply 3x2x120V to neutral.

Must suck to live in the socialists paradise.

Electricity is something like $.075/kWh, during the heating season. There is no reason for it to be expensive, other than politics.

Oil runs our world. We are very, very lucky to have it.

Ok, that explains it. Your 5 HP average is pretty pointless if you spend most of your time sitting. Why would you even introduce the number when it has no value? kWHr/mile or miles/kWHr would be of value.

If you are driving in a situation where the car is a home more than it is a car (stationary rather than moving) then I expect the relative proportion of not motive energy to motive energy can get quite high. I can't dispute that. But that has little relevance in the big picture. Your car has enough range to get you where you need to go no matter the weather or time of year, right? Then it does the job.

I would be interested in knowing how much energy the heater uses per hour. Giving the full on figure of 7 kW is not terribly useful when it won't be on at that level. I drive 110 miles (45 to 60 mph) one way each week. Up on one day, down on the another. In the winter it will get quite cold and I'd like to have a good idea of how much of my range will be used by the auxiliary functions. JL was ranting once and I figured the headlights and wipers would barely be noticed compared to the utilization by the engine. I have no data on the heater.

On Saturday, December 31, 2016 at 4:53:14 PM UTC-8, rickman wrote: ...

I did mention the mi/kWh in another post and it is on the screen shot - tha t particular one achieved 6.7mi/kWh. The conditions were pretty much ideal there, my average over a year was 5.7mi/kWh (dc) 4.8mi/kWh from the wall.

I mentioned the average power in the context of energy for auxiliary servic es. Although the propulsion system does not use significant power when sto pped the heating/AC system still does. So they can have a disproportionate effect on the overall consumption if the car is in traffic. The comparison is between the average power of the propulsion vs that of the auxiliary se rvices.

I tended to not put the A/C on even when it was hot - that gave extremely g ood energy consumption.

...

The range can drop to half of normal in cold, wet, congested traffic condit ions. A conventional vehicle's efficiency also drops significantly under s uch conditions but the range is such that it is not a concern - with a nomi nal 80 mile range EZV it is.

My Spark always had enough range for what I wanted, I was only low on one o ccasion in three years when I had to do an unexpected trip just after doing a long trip. The car managed about 86 miles with ~24 remaining - this is on a car with an EPA rating of 82 miles. With the new crop of 200 mile car s I can't imagine it would ever be a problem.

As I mentioned in my post I have seen it use ~30% of the total although a m ore typical value is only 3-5% even if I use heating or cooling.

It depends dramatically upon the driving conditions - in a similar way to t he gas engine consuming fuel even when the car is stopped so does the heati ng/cooling system in an EV. If you're at highway speeds for enough time fo r the temperature to stabilize the consumption of ~1kW is pretty small comp ared to the 20kW consumed by the drive system. If you are stuck in traffic in Hong Kong (that is one example I have seen documented) the auxiliary sy stems can consume 50% of the total energy.

California is an almost ideal place for an EV, not too hot, not too cold bu t I have seen it use 30% on occasion for short trips in cold wet conditions . In the cold I often did not have a choice in order to ensure visibility, although even then I relied more upon the seat heaters (power ~50W) rather than heating the cabin for comfort.

I tended to not put the A/C on even when it was hot - that gave extremely g ood energy consumption.

Although I have mainly commented on the auxiliary system energy consumption the propulsion system requirements also vary considerably with temperature - aerodynamic loss is basically inversely proportional to temperature - th is can give a 10-15% variation over temperature. Tire losses also go up si gnificantly when cold, wet, on bad surfaces or not at the correct pressure (basically as high as possible).

Another regime that can be difficult for EVs is fast highway driving - the aerodynamic losses go up as the cube of the speed so high speeds hurt range . Again a conventional vehicle also suffers this although the engine effic iency tends to be rising with speed as well; the gas engine efficiency is b est at high load, low RPM. Modern vehicles arrange the gearing to do this as commented by Phil.

This is the reason for Tesla going to extreme lengths to get good aerodynam ics (Cd = 0.24 the best on the market, Prius ~0.25).

In spite of all this I really enjoy driving EVs - I haven't found any conve ntional vehicles to have the throttle response of an EV - I find this is be ing made even worse in modern conventional vehicles with the goal of keepin g the engine in the high torque low RPM regime for good fuel consumption; b efore the engine can respond the transmission has to change down and the en gine rev up (and possibly the turbo spin up as well). All current EVs are single gear and can give torque to the wheels in milliseconds.

Cars such as the Chevy Volt can provide the virtues of both types of vehicl e.

kevin

25%).

It's the 305 HP six.

Cheers

Phil Hobbs (Top down on any sunny day over 40F)

e on

arger

ssimistic!

arge

comes

es

listic.

rent

ly

Of course we only have a finite amount of it. We've used up about a billion years worth so far and the oil still left in the ground is harder and more expensive to get at.

It's better seen as the energy economies equivalent of training wheels. We should leave enough of it in the ground to let the next species which evolv es a technology get off to the same flying start.

Oil is also screwing up our world. Not enough to threaten our survival as a species, but quite possibly enough to threaten our survival as an advanced industrial society. John Larkin does emphasise the point that such a socie ty doesn't have to include all that many people who understand how an advan ced industrial society actually works, or how dependent it is on a very pro ductive agricultural sector (which gets much less productive as soon as the rains starts falling someplace else).

I'm not convinced there is an EV with my name on it. I'd like something small and very sporty, but not low to the ground. Something like a small SUV with a roof rack for the kayaks. But it has to be large enough for my legs and torso. Some of the Mazdas are so small my head touches the headliner. Maybe the Bolt, but I won't be able to see one on the east coast for another three to six months.

hicle.

I test drove a Volt yesterday - technically I thought it was very good and the front seating quite adequate. However the rear seat accommodation was atrocious - I had to bend my head down a lot to get in the car and roofline was too low for my head and I'm only 5'10. In addition the cargo space was very small and in my mind badly designed.

I think the stylists or aerodynamicists had too much of a say and put the h inge line of the tailgate too far forward, it was in front of the rear pass enger's head. I would prefer losing a few tenths Cd to make the roof line bit higher, add rear passenger head room and cargo space.

I don't think it is the car for me in spite of the technical appeal.

They did have a Bolt for test drives at the dealer but it was supposedly al ready sold!

kevin