The Driving Experience
All the technical jargon sounds impressive, but how much of this is experimental, how much is practical?!
Toyota arranged for test drives at both, the racetrack and public roads. There were 4 different types of driving conditions:
1) Toyota EcoRun Challenge.
The idea was to do two sessions of a 3 lap run around the racetrack, while maintaining reasonable pace with good fuel efficiency (FE). Driver with the best FE wins, although you can get penalty points for driving slow. The track was 1.52 kms long and we were supposed to cover it in 1:50 minutes / lap. That roughly translates to an average speed of 50 kph over 3 laps. Doesn’t sound like much but remember, we had to do it in a hybrid car (Prius HV) on an unfamiliar track.
There was a demo drive of 3 laps by a professional racer who obviously knew every curve like the back of his hand. He took each curve without sacrificing any speed, and scaring the hell out of us. I think he did it in less than 1:50 minutes, but I knew even 2 minutes will be a hard one to pull off.
The Toyota Prius has average power and handling characteristics, typical of C segment petrol sedans in India. When I drove it, after the first lap, I stopped looking at the FE meter. I focused on getting the improbable 1:50 minute lap timings. The Prius had a lot of body roll over fast turns and was slow to accelerate after the curves. At the end of the first round, I had achieved about 25 kpl fuel efficiency. I was also at the top of the FE chart in my group. Thus, I decided to continue driving using the same strategy in the second round. It made more sense just to drive using common sense, rather than than letting the FE meter dictate the driving style. In fact, that is how one should drive a hybrid...using common sense. You don't have to alter your driving style to drive an HV at all. Later, you'll see a video of how the hybrid system worked while driving on public roads.
Some other journalists realised that the penalty for slow driving was minuscule. Therefore, many of them changed tactics and started driving awfully slow in the second round. They didn’t go fast on the straights, nor did they accelerate out of curves. On the other hand, I wanted to drive the car in real life driving conditions, so I continued to aim for the suggested speed and managed to do 3 laps in 5:45 minutes. That is about 1:55 minute per lap, while getting an average of 25 kpl. I was happy until I came to the results board and saw numbers like 33 kpl, 29 kpl, 27kpl etc. These were before the penalties kicked in. As I roughly calculated the penalties, I realised it hardly made a dent to their score.
I truly salute the Indonesian pair who won the challenge. They managed 29 kpl while matching my driving time. I don’t have the result sheet with me, so my recollection of exact times may be a bit off.
As I walked away from the event, it suddenly occurred to me that we got this kind of FE while driving a Prius hard on a racetrack. On a straight 4-lane highway, it could easily cross 30+ kpl.
2) The PHV Slalom Test
The next test was of a very different car. The Toyota Prius PHV, powered by
Plug-In Hybrid technology.
I wondered how different the Prius PHV can be than the regular Prius HV, at least in the driving dynamics area. Turns out that the difference is noticeable. The biggest change is the battery. While the HV is powered by a
Nickel Metal Hydride battery of considerable size, the PHV is powered by a
Lithium Ion battery that is almost twice as big, and has more than 3 times the power storage capacity. The battery is located behind the rear passenger seat. That’s like having a rear engine, in addition to the one at the front. That had to affect the driving dynamics, and I hadn’t been impressed with the Prius HV's handling on the track.
Toyota offered a brief slalom test with two tight U-turns to prove that the BIG battery won’t affect on-road behaviour. I started smiling as I just love the curves. Then, the far-eastern scribe who was my driving partner for the PHV told me to drive both the rounds as she wasn't familiar with RHD vehicles. My smile only got wider.
The number 40 refers to the top speed for the curves. The number 50 refers to the top speed for the straight stretch back. The top speeds were mentioned not for safety, but for demonstrating another feature of the PHV. And no, I don’t think they expected us to drift.
So I took off, with a race driver on the passenger seat and the other scribe at the rear. I did the slalom at the best speed I could, pulled a very fast U turn and stopped. The race driver looked quite alarmed during the U turn! After we stopped, he looked around and added it was very smooth
![Smile](https://www.team-bhp.com/forum/images/smilies/smile.png)
. The PHV was absolutely composed during the crazy manoeuver. Although I didn’t get to compare it side by side with the Prius HV, I do feel that the PHV has better handling. One thing was amply clear, the heavy battery hardly affects the driving dynamics.
I then took off on the straight stretch, not exceeding 50 kph, and ended the lap with another fast U turn. This time, the race driver was relaxed since he knew I could pull it off. Then, he asked me a strange question.
He: Did you hear the engine come on?
Me: Huh, I am not sure.
He: You stayed below 50, so it never came on.
Me: Aha, so that was the reason for the 50 kph limit!!
Since I had another round, I paid attention to the engine this time. The slalom, fast U-turn, straight stretch, another U-turn and stop. The engine was never heard, because it never switched on! In the PHV, the engine doesn’t fire up unless you cross 50 kph or the battery runs out of juice. In Indian cities, we spend 95% of our driving time below 50 kph.
A view from the dashboard. Take a look at the FE it managed even in the slalom tests:
If the bar is at CHG, it indicates that the car is charging. If the bar is at EV, it indicates that the car is running on battery. If the bar is at PWR, it means the car is powered by the petrol engine. Notice how wide the EV part is. If you are driving on crowded roads, the engine stays shut. Don't expect the party to last long though. The car has limited range if you are just sticking to EV, perhaps as little as 20 kms. After that, the petrol engine will kick in and the battery will start charging again.
My next concern was the trunk space.
Umm, that’s a lot of space. Where is the battery? Well, you are looking at it. The entire trunk is above the battery.
See the block under the trunk? That is the battery...the entire thing. The slim compartment next to the battery is used for parking the charging cable. Nope, no spare tyre in the PHV.
The PHV has a range of 870 kms under normal driving conditions. What is the FE of a PHV? That is a good question, but very hard to answer. How does one account for the external power? It may have different costs depending on whether the external power source was home-made solar or from the energy company. It is surely better than the Prius HV, thanks to cheaper external power and a bigger battery. Even Toyota doesn’t try to answer this complex question.
If you have more PHV questions,
check this page out.
3) Multi-car Track Driving
The 3rd test-drive consisted of driving 6 different hybrid vehicles on the track. The line-up had the Toyota Sai (same as Lexus HS250h), Toyota Camry, Toyota Crown Comfort, Lexus GS450h, Toyota Estima & Toyota Alphard. Keep in mind that all hybrid cars have CVT transmissions, and this is track driving we're talking about. I went in with low expectations and came out impressed. What I am trying to say is, all of them felt like regular automatic cars to drive. The Estima and Alphard are actually minivans which I drove in sports mode, just for kicks. I was most impressed by Sai since it had the best handling of them all. It surely stood out on the track.
Here's some interesting trivia. Japan has more than twice as many vehicles as India. While Indians own 18 cars per 1000 people, the Japanese own 591 cars per 1000 people. Toyota has 45% of Japan’s market share in passenger cars. Currently, 40% of Toyota’s domestic number is made up of hybrids. That alone should put all our doubts about the maturity of hybrid cars to rest.
This also made me understand why Japanese cities are full of parking lots. I saw more parking slots than people on the road.
4) Public road driving.
Later that day, we got to drive these cars on public roads. I chose the Sai since I loved driving it in the morning. I also preferred the Sai because it displays the hybrid system status via animation. You can see exactly when the motor is driving the car, when the car is charging the battery, when the engine is running the car etc.
Japanese rural roads can be really narrow (not too different from India). But the complete lack of pedestrians and extremely courteous drivers make for an incomparable driving experience.