ECO,ECO!Posted: May 2, 2011
I promised this blog wouldn’t be about fuel consumption but one of the first things people ask you about the twinair, if they’re still around after I’ve bored them senseless telling them how innovative this engine is, is ‘what will she do mister’ not in the traditional sense of speed but just how economical is it?
Fiat official figures suggest 69 mpg on the optimal cycle, but lets cut to the chase we all know that manufacturers figures are almost always impossible to obtain and obtain consistently. My first proper journey was a trip to my Mum’s in the West Midlands about 140 miles from my home in Essex, filled with regular Tesco 95 Ron unleaded, and with a few stints at about 10% above the national limit I achieved 44.0 mpg according to the on board trip computer. Not bad for a brand new engine I thought.
Some words now about the performance. Firstly, yes for possibly the smallest mainstream petrol engine in production, the twinair is not just a town and city car. It happily cruises at 70mph and slightly above with performance in reserve if required. Don’t get me wrong it’s no AMG Merc or large diesel cruiser drunk on pints of torque, but it is not dangerously underpowered as some people assume of small engines; in fact it’s not underpowered at all full stop. funny I should mention diesel torque, because it’s torque that is the twinair’s trump card 107lbs p/ft delivered in the low to middle of the rev range. This is more than a fair amount in a car that weighs just over 1000 kg and means that the twinair feels more than good for it’s claimed 10.7 0-62 sprint. Happily, with less than 1000 miles on the clock, more performance is to come.
Getting the best mpg is also dependent on the use of the ECO button, unlike the sport button fitted to…er… sport models of the 500 with the 1.2 or 1.4 engines that sharpens up throttle response and other inputs; the twinair has the ECO button. Placed to the left of the hazard lights in the centre of the dashboard a press of the ECO button effectively re-maps the engine in an instant curtailing a percentage of the engine torque. it makes perfect sense to leave the ECO button on when cruising on the motorway (the word ECO is displayed permanently on the digital display when in operation) and most of my current consumption figures have been achieved using it, including the 44.0 above. You only really need deactivate ECO when you need full power e.g. to overtake something safely or tackle a steep incline. The only slight criticism I have of the ECO button is, well, the button itself or rather the placement of it. It’s too much of a left arm stretch away a far better idea in my opinion would have been to integrate the function on one of the stalks, or perhaps a steering wheel button, so that if you needed full power again quickly, it would only be a finger flex away rather than an arm movement away. Just a thought.
Once in the Midlands a mix of A and B road driving was enjoyed and the mpg actually crept up a little to the higher 40’s. don’t write the West Midlands off if you’ve never been, yes it’s an urban conurbation purely man-made with the UK’s second City at its heart, but its edges and the surrounding Counties, particularly Shropshire hold some stunning sites. The beautiful town of Ironbridge, perhaps birthplace of the industrial revolution is just one of them.
Nearly a week later and no fill up needed since leaving Essex it was time for the trip back. The tank was nearing empty and a full fill with Shell Fuel Saving Regular unleaded was selected and the trip computer reset. The return journey yielded exactly 52.1 mpg for an identical route and near identical conditions, an improvement of 8 mpg. Too early to tell, but could this point toward what I’ve suspected for a while, that Shell’s fuels really are the best on the market? Another week has passed with purely urban driving and the trip reading dropped to around 49mpg.
I filled up again on Friday (missing an awesome Audi R8 V10 Spider spot) as those who follow me on twitter will recall! I decided to try Tesco’s Momentum 99 Ron, so far in purely urban driving this is returning a very disappointing 36.5mpg with ECO mode on. It does seem to have smoothed out the engine’s slight hesitance at the very bottom of the rev range just above idle speed and it does feel more eager even with ECO engaged, but these aren’t reason enough to stick with this fuel and its increased cost, unless consumption drastically improves.
next post – some early driving impressions. Thought’s and comments always welcome please.