Remember zapping ants with a magnifying glass?

Sometimes these are called "range extenders" (optional on the BMW i3, included on the Chevy Volt) - the car is a true electric, but if the batteries run low the car will automatically start up an on-board gas generator. The generator is only used to generate electricity, not directly move the car (like in a hybrid).

mlts22 wrote:
then just plop in an Onan generator with a battery charger and a fuel tank.

They do, it's called a hybrid. EV by definition does not have a onboard generator. That's the whole point of an EV.

I've wondered why someone doesn't design a true EV, then just plop in an Onan generator with a battery charger and a fuel tank. This would solve the problem, as the genset could run on gasoline, diesel, or even LP gas, and it wouldn't require that much extreme automotive engineering. Best of all worlds, EV range, and if one needs to go on a longer trip, the genset fires up and keeps the batteries topped off.

pianotuna wrote:
Hi mena,

Populate the roof of the RV with solar panels. Use that to power the BEV or Phev.

I have enough room for one 300W panel and maybe a couple more very small panels. Not near enough to compensate for an EV. I DO have enough roof space on my house for at least 30 panels, likely more.

BTW, regular hybrids all have regenerative braking.

Francesca Knowles wrote:
I always wonder about how the electricity used to charge hybrids is factored in to the "MPG" claims. When folks say "I get > 50mpg", is that after they've bought whatever electricity the car needs for recharge?

MPG is really an economic factor, and it seems to me that "fuel use" ought to somehow account for whatever electricity is being consumed by the car.

Are there "energy use per mile" figures, expressed as a total of energy units(?) combining both gas and electric?

Depends on the car.

For hybrids that are not plug-in hybrids (the VAST majority fall into this category), all energy used is generated (one way or another) via the gas engine. For mine, MOST of the electricity needed to run the electric motor is captured through regenerative braking (recovering energy that, in other cars, is wasted to heat). The rest is generated by the engine while cruising.

Since all of the energy comes from gas, how can my car average > 50 mpg? It's efficient. The engine is just big enough to propel the car at speed with a little extra for acceleration (but not much). The energy needed to accelerate quickly is provided by the electric motor - these have the advantage of providing very high torque through a wide range of RPMs (from zero), allowing a relatively small electric motor to provide quite a lot of umph for acceleration. (A few stats for my car: The engine is an 80 HP 3 cylinder. The electric motor is 18 horsepower.)

In addition, the car is very lightweight and aerodynamically shaped. Operating just on gas (which I did for about 2 weeks when the hybrid battery needed replaced) it still averages around 42-43 mpg.

For my car, a "energy use per mile" value isn't needed. mpg works fine, as all of the energy comes from the gas engine. It really gets > 50 mpg.

Plug-in hybrids (Chevy Volt, Prius PlugIn Hybrid, etc...) and electric cars (Tesla, Nissan Leaf, Chevy Spark electric, etc...) get some, or all, of their energy from the grid. The EPA has a formula that they use for calculating mpg for plug-in hybrids and electric cars that yields mpge (miles-per-gallon equivalent). I believe that this is the "energy use per mile" value that you're looking for. It's really only useful for comparing one such vehicle with another. (e.g. one electric car might get 118 mpge, while another gets 106 mpge... The former will use less electricity per mile.)

Hi mena,

Populate the roof of the RV with solar panels. Use that to power the BEV or Phev.

Francesca Knowles wrote:
I always wonder about how the electricity used to charge hybrids is factored in to the "MPG" claims.

I don't think that's factored in. I DO know that without a second meter, a PHEV or EV would put me in the next higher tier for electricity in CA.

I always wonder about how the electricity used to charge hybrids is factored in to the "MPG" claims. When folks say "I get > 50mpg", is that after they've bought whatever electricity the car needs for recharge?

MPG is really an economic factor, and it seems to me that "fuel use" ought to somehow account for whatever electricity is being consumed by the car.

Are there "energy use per mile" figures, expressed as a total of energy units(?) combining both gas and electric?

Eh? What kind of Honda could I have gotten in 2004 as a 1 year old used car for $16K that would have gotten > 50 mpg? (The Honda Fit wasn't introduced in the US until 2006.) For that matter, what kind of non-hybrid car of any make or model could I have gotten in 2004 for that amount of money that would have gotten > 50 mpg?

Most of my drive to work is highway (at 70-75 mph). The Honda Insight (first generation) has better mileage on the highway than on surface streets (official EPA estimate was 48/59 - I've averaged 51.8 mpg over the life of the car so far). The hybrid system works differently than the one in the Prius, which does better on surface streets.

Hi atries,

You have to compare apples to apples, not apples to oranges.

A plain jane non hybrid of the same make and model is significantly cheaper, and mileage is often nearly identical, particularly at highway speeds. It takes a lot of miles before the fuel savings add up to the difference in price--and the math may show it never breaks even. A Phev may or may not be better.