Best fuel saver vehicle

Proton Inspira can go 900 kms on a tankful

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It’s like the early 1980s again… I don’t mean like the days when you could get a BMW 320i for RM60,000 or when a litre of petrol was around one ringgit. I’m talking about fuel economy runs which were popular back then because it was thought that people would care about fuel consumption. But at around RM1 a litre then, most Malaysians didn’t consider fuel consumption as a major factor in choosing a new car and eventually, economy run competitions faded away.

In 2011, the cheapest petrol you can buy is almost 3 times what it cost in the early 1980s and it has been increasing frequently in the past few years. So motorists now care much more about how much fuel their car uses and the car companies seem to sense that it’s time to highlight the economical nature of their models.

This year, I’ve already been on three economy runs – the first with a Honda Insight to Melaka, a second one with a Ford Focus TDCi in early May, and last week, another one in a Proton Inspira 2.0 from Shah Alam, Selangor, to Penang and back. If you subscribe to our Twitter feed, you’ll know that the best result achieved from this run was 934 kms potential range with the Inspira’s 59-litre tank which lasted the entire journey. Here’s the story of the Proton Inspira Economy Challenge (PIEC).

Unlike the two earlier runs, this one by Proton was much more realistic in that the organizers set conditions that forbade extreme ‘techniques’ to stretch each litre. With most runs, other than setting a specific time to arrive at a destination – with penalties for lateness – there are no other conditions as to how the driving is done. So it was possible to switch off the air-conditioner (to eliminate compressor load), increase tyres pressure substantially (to reduce rolling resistance) and roll downhill in neutral gear. You can get fantastic fuel economy doing these things but who really does their motoring like that? For the PIEC, all these techniques were forbidden and to ensure that the participants didn’t cheat, an independent observer was placed in each car.

Proton’s challenge to the media was to go as far as possible driving the Inspira and there were 10 cars in the event - five driven by owners invited to join the event and five driven by journalists. Following usual practice, the bonnet and fuel lid were sealed and the organizers even installed a box over the air-conditioner controls so they could not be touched (the settings were the same for all the cars, with the air-conditioner running all the time).

At the start of the run, the range was projected as 310 kms with a full tank but after economical driving for some distance, it increased and when the fuel tank level was half, the potential range was 470 kms

I was again partnered by Daniel Fernandez (editor of Asian Auto) whom I was happy to have as he had shown that he would not go crazy in the mobile sauna room and also had the patience to drive at well below the speed limit on the highway. This time, of course, we expected the going to be a lot more ‘civilised’ as the cabin would be cool. The only thing was that the fresh air vent was also set to open so there were occasions when unpleasant smells got in!

The starting point was Proton’s head office complex in Shah Alam and as it is right beside a major highway, it was thought that we could depart and join the North-South highway for an easy drive north (no sweat, literally!). But an early morning downpour (plus being a Monday morning) caused a long jam and it wasn’t until past the Damansara turn-off that I could maintain a steady speed. In the horrendous jam, the fuel consumption was terrible – as bad as 4 kms/litre (converted from the display on the instrument panel which shows in ‘litres/100 kms’).

Paddle shifters on the steering wheel which are standard for the Inspira 2.0 made it easier to select gears quickly on the CVT. (Right) Air-conditioner controls were covered to prevent us from turning the system off!

Once it was possible to cruise at a steady speed, I began to experiment with various ways of driving, all with the objective of keeping the revs as low as possible. However, being a 2-litre Inspira, it was equipped with a CVT (continuously-variable transmission) which has different and unusual characteristics from a normal automatic transmission. Though it has 6 ‘speeds’, it doesn’t really have gears and the ‘speeds’ are pre-set steps in the transmission system to simulate shift points. The good thing about the CVT is that it allows greater fuel efficiency and even at 100 km/h, you can get a ridiculously low rpm.

Observing the bar graph which displayed real-time consumption, it became apparent that a cruising speed of between 70 km/h and 85 km/h was best. Too slow and the CVT would refuse to go into the highest ratio. So the strategy was to manually shift up (using the paddles mounted behind the steering wheel) to top gear as quickly as possible. Unlike a manual transmission where you might shift up too fast and labour the engine, automatics don’t allow you to get into a gear that’s too high until it’s okay.

Another thing that I found was that when you push the lever to the right into manual shift mode, the revs tend to be marginally higher. This is probably because it’s a ‘sports mode’ so the transmission is kept ready for stronger acceleration. But if you keep it in ‘D’, the transmission also tends to shift down and bump the revs up frequently. So the trick was to use sports mode to shift up quickly and once to gear was reached, to push the lever back to ‘D’ so the revs would be stay at their lowest.

Related article: Proton to offer CVT on other models 

Red lights are really bad for fuel consumption and if you know you're going to be stopped for a long time, shutting down the engine helps. It's helpful to keep an eye on the lights and if they are red as you approach, slow down to coast the remaining distance and see if the lights change and you don't have to come to a stop

Being a 2-litre version, the car also had cruise control and this feature is useful for fuel-saving. It maintains a more steady throttle position than would be possible if you tried using your foot pressure to maintain a desired speed. So if your car has cruise control, use it when you are able to travel long stretches without much traffic.

After the lunch stop in Ipoh, we were made to drive along the old road to Kuala Kangsar which was again to get ‘real-world’ driving conditions. Apart from the fact that it rained and reduced visibility, there were also a lot of heavy vehicles to overtake and then the climb uphill by the side of the cement plant. All these bumped up the consumption but we expected to compensate when we got back on the highway.

From the experience with an earlier run, we were apprehensive about the traffic conditions in Penang. We arrived late in the afternoon as rush hour was starting so it was a nightmare trying to drive economically. We were fortunate to get a ‘green wave’ through the lights again which helped and when we got to the hotel, we had travelled 330 kms and the remaining range was 440 kms. This would mean an average fuel consumption of 13 kms/litre.

Heavy rain and large lorries prevented steady speeds, impacting fuel economy severely. The GPS unit provided by the organisers for each car showed the projected time of arrival so we could pace ourselves

The tripcomputer provided average fuel consumption as well and as we tried different methods of driving, the figure would go from as poor as 5 kms/litre to 22 kms/litre. This was especially so when we started off in the morning and the consumption would be really terrible because the computer was using limited data; as the distance increased, it would adjust the reading which would typically become better.

Likewise with the range remaining which would also be dependent on how you had been driving during the times it took readings. You could be driving economically most of the time and then when you happened to drive aggressively or idled for long periods, then the range would become less. So the important thing to remember is that the range remaining is only an indication and you should never rely on it 100%. Anyway, when the level is very low, you will get a reminder that you should refuel as quickly as possible.

The journey back was less eventful as it was all on the highway. Our speed averaged 70 - 80 km/h and most of the journey was done using cruise control. The only time we had a panic was near Sg Buloh where roadworks had caused a jam to build up and that affected the consumption a bit.

Economical driving techniques can make your tank last