Driving Economically

Last week Beth’s car was in the garage having some work done on it for the day, so as a courtesy car we were given an 11 plate Ford Fiesta with the 1.25l Zetec engine. In some ways this was a bit of a flashback for both of us as ten years ago we had two of the earlier version of the car with the same engine. Needless to say it reminded me why I prefer having a diesel engine in a car as I really missed the low rev torque you get with a diesel compared to a petrol.

Having said that, there was one thing that was really annoying.

I spotted it as soon as I drove up to the end of our road. Out of the corner of my eye I saw a warning light come up on the dashboard, but when I stopped at the junction it was gone, it came up again a short time later and was again gone when I stopped. Eventually I spotted it was a green upward pointing arrow – the gear shift indicator that is now standard on all of Ford’s ECOnetic models. The official paperwork suggests that the gear shift indicator senses the way the vehicle is being driven, taking account of road gradient, vehicle load and individual driving style and identifies the most suitable gear change point. However in this case whatever the road was doing the most suitable gear change point consistently came up at 2000rpm.

Having established what the mystery light was it was then interesting to see when illuminated. Much like an automatic gearbox it has no idea of the road ahead so would come on with some crazy suggestions such as just before a hill, or coming up to a corner, but what was particularly interesting was that for a 40mph road if you follow the gear change indicator and stay within the speed limit the engine was noticeably labouring, but stay down a gear the light was almost permanently on. You could lower your speed a little to get rid of the light which would certainly reduce consumption, but given that everybody else is doing 40mph what will that do? Increasing revs to stop the engine labouring would work too, but then you’d be speeding.

Indicating when to change gear to highlight fuel consumption is laudable, but producing more efficient cars isn’t just about sticking a light on the dashboard. You also have to ensure that the cars encourage rather than discourage that behaviour. Improving fuel consumption is certainly about changing up earlier, but it is also about minimising gear changes, i.e. you want the car to be able to cruise without having to change up and down a lot. For UK roads this means that the car needs to be able to be at comfortable mid-range revs at 30mph especially, similarly at 40mph. With the Fiesta – and this was a problem with ours even ten years ago, thanks to the gearing, 40mph sits just at the point where you’re changing up.

Before everybody leaps in and points out the reason, I’m well aware that the Fiesta is developed for the European market, where everybody else has speed limits in kilometres not miles, which means that road speeds are all a bit different, so it’s quite likely this won’t be a problem across the channel, or even across the Irish Sea, but equally they have to especially make cars for the UK market with right-hand drive. Gearing a car differently for UK roads is probably too expensive, and since the UK won an exemption to the requirement to go metric for roads switching to kilometres here is unlikely to happen, but surely it’s not a problem to at the very least change the programming on the indicator so it doesn’t keep flashing up at 40mph?

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