Hybrid Cars

June 2013

As a car enthusiast I’ve always felt that hybrids were a technology cul-de-sac, a sop to green credentials for a country where diesel is strictly reserved for truckers. My understanding of the Prius was that it was an underpowered car carrying around some slightly useless extra weight in the form of largely unused batteries and not very good fuel consumption compared with a modern diesel car.

Two weeks ago I took delivery of a friend’s 2006 Prius which I’m going to look after for at least 12 months while she’s travelling the World. My views have already changed so radically that I’m going to log some of my thoughts  here during my time with the car.

Before the car arrived I read up about it as far as possible. In my view the UK motoring press has suffered for years from too many chocolate lunches courtesy of Audi and this was borne out by their lack of understanding of the Prius.

Further reading has discovered some very active user groups. Of course being a largely dealer service only car the user groups discuss fuel economy rather than fixing the oily bits.  Also I’m surprised to find a huge number of cars on Autotrader with 150,000 miles and not particularly cheap. Is this an age where owners begin to worry about battery failure and how does a 1.5 cope with high mileage?

My interest in the car grew rapidly on my first drive. Firstly the M4 was blocking up and I immediately was impressed that when the traffic came to a halt everything went quiet but the air conditioning kept blowing cool. Wow, that is really good.  I’m a great believer in being relaxed when I drive and the frustration of sitting in a traffic jam is really mitigated by this simple innovation together not having to watch a fuel gauge drop while you are waiting in traffic.

Secondly I just had to turn on the screen which shows what is happening with the engine and battery. The simple answer is quite a lot. The engine is charging the batteries all of the time it is on, but equally cruising at 30-40mph the car is often in battery only mode , regenerating the batteries whenever it’s on the ‘overrun’. But also it uses ‘kers’ mode a lot, the battery power really helping with acceleration in kickdown.

Thirdly was ease of use. I note that the Prius comes in for criticism for having an American/Mercedes style foot operated parking brake and a transmission park switch which can apparently be operated while moving at speed. In practice like with most automatic transmissions there is no need ever to use the parking brake because the transmission Park does the job better. But what is really nice about stopping the Prius is that one comes to a halt on the foot brake, pressing the power button engages Park automatically and then you pull out the key. That’s it, press Power, pull out key. Cool.

I don’t plan to check the effectiveness of Park when moving…

I’ve always rated the Series 3 Espace as having the best instrumentation, a digital unit displaying minimal information but high up and well within peripheral vision. The Prius has a similar amount of information tucked way ahead and just under the bottom edge of the screen. Excellent position, shame about the 80’s green display and why isn’t the clock there too? Even our ’96 Toyota Starlet manages a clock just under the screen! Like the Espace the Prius has no rev counter and that makes sense as I understand the engine is either on a constant 2000 or 4000rpm. But it would be good to have something displaying this information such as a series of lights saying e.g engine on tickover, 2k or 4k to encourage a softer touch on the accelerator.

A five day visit to Cornwall and Devon and time for an update.

I’ve been driving the Prius occasionally over two months, alternating with my 254,000 mile Mercedes C250TD. While the Prius was the obvious choice to take on our short holiday it wasn’t my preferred option. Some of its shortcomings are beginning to show through, the more so after our trip. Firstly the steering is completely devoid of feel. It goes where you point it but there’s no feedback from the front wheels through the presumably electric power steering. The Merc’s vague steering is probably its worst characteristic but it still has more feedback than the Prius.

On flat roads and motorways the the Prius cruises very well. The power  constantly cycles, the batteries either charging or providing power to the hybrid. But on the switchback hills of the A30 in Cornwall the motor is constantly running up to a noisy 4000rpm which actually becomes quite irritating. The latest Prius has a 1.8vvt engine and I suspect that is to give it more torque to tackle such hills at 2000rpm.

The steep Devon hills demanded 4000 revs even more often and this dropped the cars average mpg down to 49.5mpg* see below. Not bad for a 1500 carrying three people and their luggage but I couldn’t help feeling that a diesel would have done a better job with less fuel.

So where does a 15 year old high mileage Merc score over the Prius? The Toyota has surprisingly high road noise combined with some wind noise. It’s probably quite light at the front but certainly lacks the Merc’s solid attitude on the road. That said it never became uncomfortable.

Terminal engine failure of my Merc (the oil seal failed on the turbo and injected sump oil into the cylinders under pressure) caused me to take the Prius on a 360 mile round trip one evening by motorway. It was fine, I remained comfortable and overall not a bad journey as the roads were clear and I had the cruise control on 77mph virtually the whole way except for about 30 miles of 50mph roadworks. I had a passenger for half the journey only.

However I’d reset the trip meter when I topped up with fuel at the start of the drive and had to refuel just two days later. A quick calculation showed that far from the 49.7mpg the Prius information screen was telling me I’d actually achieved just 40mpg! What? I own a Citroen C3 and a Toyota Starlet. They are both 1340cc and both achieve over 40mpg at motorway speeds.  So why can this incredibly sophisticated Prius only achieve 40mpg and why is the computer optimistic by 20% and the speedometer optimistic by nearly 10%? I need to check the odometer now to see how inaccurate that is…

After a year of intermittent use it’s time for some more thoughts.

I recently discovered that the Prius is the second most reliable car on the market. All that clever technology is that reliable? Well done Toyota. Presumably the most reliable car is a Lexus with the same power unit…

I also understand that the reason for all those high mileage and high priced Prius’s is that battery failure is very very rare even on old cars. If the 1500cc engine is anything like the 1360cc one in our Starlet I’m sure they are not challenged by high mileage either.

The fuel consumption varies enormously but the more I drive it the more I appreciate that it makes a great commuter and town car but motorway cruising and hilly rural use are not its strengths.

June 2015

Two years on and the Prius is returning home to London.

I wouldn’t buy one although I’m considering an all electric car to replace our ageing C3.  The Citroen does just 16 miles almost every day so I’m seriously looking at a Mitsubishi I Miev or Citroen C0 to cope with its easy commute and local running around.