Why Hybrid Cars (Part 1)

Posted on Tue 06/22/2010 by TonyfromOz

Recent fuel consumption figures here are quoted in Litres/100Km, and I have done that for a reason, that reason being that the U.S. gallon is slightly smaller than the Imperial Gallon we use here in Australia. Where I do mention fuel consumption, I will have the corresponding figure for U.S. gallons in following brackets. As an example 40MPG here in Australia translates to 33.3MPG in the U.S. All monetary values are also in Australian Dollars, (AUD) and the current exchange rate is $AUD1 = $US0.83

When it comes to cars, the vehicle you drive is a personal choice. I have never considered owning a Hybrid vehicle, mainly due to the original cost. My first car was a small Toyota Corolla back in 1969, and since then I have owned 3 more Corollas and a Camry, all purchased new. I currently drive a Holden Astra, a vehicle falling under the GM banner, manufactured and sold in Europe as the Opel Astra, in the UK as a Vauxhall Astra, and in the U.S. as a Saturn Astra.

Fuel consumption was not really the rationale behind driving those small cars, but over the years it has certainly helped. With all the Corollas, I averaged 35MPG (30 U.S.) around town, and 42MPG (35 U.S.) on the highway. The Camry, and the Astra gave me 32/40. (27/33 U.S.) Three of those 4 Corollas I traded up at around 100,000 Miles and the Camry made it quite comfortably to 150,000 Miles for the 16 years I owned that car.

With the recent introduction of Hybrid vehicles, people have developed an opinion, one way or the other. As I mentioned, cost is the factor in my consideration, so it was never a consideration. From some cursory checking, fuel consumption, although better than for most current cars in vogue, those medium and large SUV’s and medium to large sedans, that consumption is (in real life driving applications, and not just the manufacturers quotes) only a little better than for small cars, and I’ve been driving them for more than 40 years now. So, those real application fuel consumption figures do not necessarily negate the original outlay from my personal perspective.

The principle, however, did interest me, as I come from the background of an electrical tradesman.

I recently got the chance to drive one of them, as my brother has recently got one of the new generation Hybrid Camry’s, constructed here in Australia. He has had it now for 5 months, and is overjoyed with it. As interesting as it was, the cost is still the main factor for me. It did however give me a chance to see first hand how they drive in most applications. I can’t say that this was a full evaluation, because I only got to run up around 70 miles or so, locally, in a built up stop and go situation, and also on the open highway.

The car is very easy to drive in every situation, and has everything that you would expect from a current new car. What impresses me most about this Hybrid Camry is that it looks for all intents and purposes like any other Camry, getting away from the distinct look of the Prius that separates it from other vehicles, the general impression being that those Prius drivers give the (false) impression of being somehow superior because they are somehow more environmentally conscious. So this Camry gets away from that, in the eyes of other drivers.

It is absolutely silent inside the car. Press the starter, and nothing, because all this does is to start the electric motor. If you ease away slowly, then the electric motor does the driving. If you just drive off normally, the electric motor starts the engine which then drives the car to ‘around town’ speed, when the engine stops and the driving is just done by the electric motor. Stop at the lights and the engine stops completely. It’s a little disconcerting at first, but it’s an easy thing to adjust to.

On the highway, the car cruises comfortably at that highway speed, here in my case at 110KPH. (nearly 70MPH) Whilst on the highway, the engine provides the sole driving force. Any small rise in the road or hills , then the electric motor comes in to assist with the driving, and you don’t even notice the change as you keep the same pressure on the accelerator pedal. That engine revs at a surprisingly low level, mainly because of better gearbox technology, and really, if any extra ‘grunt’ is needed on the highway, then the electric motor comes in to assist.

Perhaps the most disconcerting thing of all is the above display you will see in the middle of the dash in front of you. With the images shown here, if you click on them, they will open in a new and larger window.

The wheels are on the left and the electric motor is symbolised by the battery like symbol on the right. The engine is between them. During all driving applications there is a ‘flow arrow’ showing which element is driving the car.

This image progression is taken from the owners manual, and I’ll give a small explanation from top to bottom.

The first image indicates driving around town when the electric motor only is driving the vehicle.

Next shows what you might see when pulling away from a stop at normal driving conditions, and also out on the highway when climbing a small rise or hill.

Next shows normal highway driving.

The next image shows what you might see when descending a small rise or hill, the motion of the wheels is driving the electric motor as a generator and recharging the batteries. You have to get away from the impression of ‘free wheeling’ as all the car’s capabilities are still immediately available, no matter what you do.

The last image shows what you might see at a complete stop.

As you can see from the battery image, it shows the ‘relative’ state of charge for the battery bank, which I will discuss in a further post in this short series.

Now, as to fuel consumption, it seems quite impressive for a medium large vehicle. My brother has kept me appraised of those consumption figures, mainly because I am from the old school, raised on MPG, instead of the new Litres per 100 Km figures used. Because of that, and as I have been keeping figures for all my cars, then he knows that I can convert the figures a lot quicker than he can by converting the two metric figures and then doing the relevant math. To that end, each time he fills up, he has been ringing me and asking me for the conversion, so I have recent, and accurate data. The previous car he owned was one of those ‘tiny’ Toyota Yaris, and while he got good consumption from that, these figures are even better than for that vehicle. His earlier car was a Ford Territory, an SUV similar in nature to the Ford Explorer in the U.S. This Camry Hybrid is getting figures almost double and triple than for that Ford he once owned. He’s averaging 42MPG (35 U.S.) around town, and on the highway, he’s getting 50MPG (42 U.S.) The generic figure quoted by Toyota is for a combined cycle of 6 Litres/100KM (39.2MPG U.S.), so even though highway figures are slightly better than that, driving in a real situation might show something different, hence I have tried to show actual figures here for those specific areas.

This image shows the whole dash, and here, this is for the vehicle without the starter being pressed, so it is at rest.

The gauge second from left indicates an approximate fuel consumption for driving conditions. That gauge rises when the engine starts and under acceleration, but for highway driving, it’s quite easy to sit the needle in that lower section where there are two bars. That inside bar is coloured…..wait for it…..green, and what other colour did you really expect it to be.

My brother says the range is astonishing really. The fuel tank size is 65 litres. (17 Gallons U.S.) He’s regularly getting between 800 and 900 Km (500 to 560 Miles) from one tank, and still not having it close to empty.

This excellent fuel consumption is probably more important here in Australia, where we are currently paying on average $1.25 per litre for fuel and more. Now here is where I need to explain just what that means in U.S. figures because we pay a hell of a lot more for petrol than you guys do, that $1.25 being the base price. When we convert from litres to U.S. gallons, and then convert the currency rate, this translates to a U.S. equivalent of $3.90 per gallon, and keep in mind that this is our base price, and we have been paying that level, and more often than not, a considerably higher amount, for the last five years or so.

So, when you guys grumble about gas maybe costing $3 per gallon, be aware we pay a lot more than that all the time.

Realistically, those fuel cost savings turn into something substantial over time, but even so, the extra cost at initial purchase is something it would still take time to recover with that smaller use of petrol.

That explains some of the generalities of the car, and to explain the principle, I’m actually going to have to explain some electric principles to you. They are complex for non electrically trained people so my task is to make that readily understandable. In so doing, it will become a little more obvious why Hybrid vehicles of this nature are a better proposition than vehicles powered solely by electrical motors.

In Part 2, I will explain some of that theory, and it’s application for this particular vehicle.