2016 Toyota Prius (photos, specifications, Cd 0.24)

[oldtamiyaphile]

Originally Posted by NeilBlanchard

Their electric motor is probably 92-94% efficient ALL THE TIME. No need to warm it up, or maintain the right RPM.

Toyota had a chance to really up the ante - and they barely managed a tweak. The aero could be better, and they need to go big battery with plugin charging.

The Tesla Model S is about TWICE the efficiency as the Prius.

The Prius accelerator is just that, it controls your rate of acceleration, this is quite different to a accelerator in an ICE or EV where it controls RPM. The ECU automatically maintains the most efficient RPM and load, more or less independent of your throttle position.

I couldn't disagree more on the plug in hybrid. Why carry around a big heavy battery that reduces the car's efficiency and makes it more expensive to buy and run? The point of a hybrid for me is to have just enough battery to maximise fuel savings, for me at least it's not common to have the battery full, I'd say Toyota have sized it right for 90% of users.

My old tech G2 Prius costs 5c/km with petrol costing $5+ a gallon. If we had $2 gallon like you guys that would be 2c/km, a G4 should be in the sub 2c/km range. Your figures show 3c/km for your EV use.

Well to wheel studies have shown that EV's and Hybrids are just about the same in terms of Co2 depending of course on the cleanness of the grid. Even so, you'd have to be pretty keen to bother plugging in a hybrid if you know it's going add around one third to your fuel bill.

The US grid is 90% efficient, your charger is 90% efficient, the batteries under charge are 80% efficient, the batteries under discharge are 80% efficient, the inverter is 90% efficient, and the motor is 80-90% efficient. As high as each of those number is, those small inefficiencies do add up. You get 37% based on those numbers.

Even if you use best case scenarios (these numbers don't exists outside a lab as inverters/chargers/motors are most efficient under load while batteries are least efficient under those loads) of 90%, 95%, 90%, 90%, 95%, 90%. The EV is only 60% efficient. The Prius ICE is 40% efficient but that doesn't include energy recaptured via braking.

The likes of Leaf, e-Golf and the various California specials are no better than a Prius. The Tesla is a big step forward, but it's a long way from being twice as efficient. If also costs three(?) times as much, so you could buy a lot of solar panels (or similar investments) to more than offset your inefficient Prius, Golf, Leaf etc.

[serialk11r]

The issue with larger batteries is that I'm not really convinced that everyone actually has access to charging everywhere. If you were guaranteed that, the fuel savings might be worth it.

I've argued about this with Tesla fanboys before, if you live in the city where there's scarce parking and shared parking lots with no chargers, you'd be very thankful for what a few gallons of gasoline can do.

Most people in the world live in densely populated areas where charging is an issue. It doesn't make a lot of sense to design the car to take a bigger battery that only a minority of people will use.

[oldtamiyaphile]

There's a certain irony in the fact that inner city use where EV's shine is exactly where you'll find the biggest charge issues, at least in the short term.

[niky]

I think that short term will prove very short. In urban areas, adding recharging points where they're certain to see high usage will make much more sense from an ROI point of view than setting them out in the countryside for top-offs that will be few and far between.

[sendler]

Originally Posted by oldtamiyaphile

You get 37% based on those numbers.
The Prius ICE is 40% efficient but that doesn't include energy recaptured via braking.

He is getting 140 MPGe, wall to wheels via a Kill-a-Watt, in either of his electric cars and you are getting 51 MPG in your Prius.

[oldtamiyaphile]

MPGe is a fictious number dreamed up by the EPA to encourage EV uptake. Yes I know based on BTU's in gasoline.

The average coal burning plant is 33-40% efficient. His 140MPGe could really be 46-56. 42-51 including the 10% that's lost in the grid.

If I account for the 3kWh required to produce a gallon of gas, and the energy used by tankers (ships and trucks) to transport it, my Prius sits at ~48mpg.

The true MPGe varies wildly depending on where you live. Measuring at the wall is only relevant in the hypermiler sense of improving your own stats.

[oldtamiyaphile]

Originally Posted by niky

I think that short term will prove very short. In urban areas, adding recharging points where they're certain to see high usage will make much more sense from an ROI point of view than setting them out in the countryside for top-offs that will be few and far between.

You sort of need a charge point at more or less every space. Who's going to move their car in the middle of the night so their neighbor can plug in? What about people who park in the street? What's to stop all those copper cables being stolen?

[user removed]

Gas here is now at $1.559 at the lowest priced stations (thanks gasbuddy). That's less than 3 cents a mile based on my average mpg in my $12.9 k Mirage.

Old tamiyaphile has posted significant counterpoints to the electric car agenda. In specific scenarios, electric is the better option. In other scenarios, liquid fuel is the ONLY option.

Agendas are like blinders on a horse, preventing rational observation and analysis.

I should know, I have one myself.

regards
mech

[sendler]

Originally Posted by oldtamiyaphile

MPGe is a fictious number dreamed up by the EPA to encourage EV uptake. Yes I know based on BTU's in gasoline.

There is nothing fictitious about MPGe. Or kWh/ mile. Or Joule/ mile. Choose whatever you want. They are all the same. And show that an average EV car conversion such as the eGolf or eSpark will trounce the wall to wheel, pump to wheel efficiency of the best cutting edge ICE car by 250%.

[oldtamiyaphile]

Originally Posted by sendler

There is nothing fictitious about MPGe. Or kWh/ mile. Or Joule/ mile. Choose whatever you want. They are all the same. And show that an average EV car conversion such as the eGolf or eSpark will trounce the wall to wheel, pump to wheel efficiency of the best cutting edge ICE car by 250%.

At this point I think you're trolling? All those metrics measure energy usage AFTER the energy has been produced. It's like measuring power output at the flywheel of an ICE (after it's been produced) and proudly proclaiming some fantastical efficiency figure.

Let's see the grams of coal/nat. gas/oil/mile calculation and see how that stack up. Most of the US doesn't have the clean grid of the east coast.