ECONOMY DRIVING: What's the best way to cut fuel costs?
24 March 2009
There are several ways to reduce your fleet's fuel bill, but here BusinessCar does the real-world maths on three methods you might not have considered.
1. Swap to hybrids?
With manufacturers heading off in so many different directions with regard to fuel- and CO2-cutting tech, it's difficult to know which way to turn for the best.
Honda's new Insight is a prime example, as petrol-electric hybrids have split opinion like no other in recent times. On the one hand, they're the future of the car market, at least in the short term, while detractors say they're no better than diesels, more expensive and are actually worse than standard petrol cars on the motorway where the electric motor contributes little (see box, 'Hybrids on the motorway'). And somewhere in the middle of the hybrid debate are the people who see them as a short-term solution until we get to a real answer to the issue of low-CO2 transport.
To test whether fleets should swap diesels for hybrids, BusinessCar put the latest petrol-electric hybrid, the Honda Insight, up against a fuel-efficient diesel, in the form of BMW's 118d.
Honda claims its new lower medium saloon is one of the most important cars for the corporate sector in the past decade, and that various features, including those designed to encourage eco-driving, will mean its new model gets closer to those claimed fuel consumption figures than drivers and business car managers can normally expect.
The 1-series we've used, meanwhile, has caused a bit of a stir in the corporate world because it scrapes into the 13% BIK banding, giving the masses more used to a Vauxhall Astra access to a company motor with a BMW badge. Complete with stop-start technology and a host of CO2- and fuel-cutting measures under the Efficient Dynamics banner, it seems a worthy rival to the Insight for the purposes of this test.
We've thrown in a third competitor, too. Toyota has also jumped into the stop-start arena with its 1.3-litre petrol Auris model, and with the price of petrol maintaining its gap below diesel, we thought we'd see how a stop-start petrol model would fare in the urban trial we had planned.
Ah yes, the test itself: three cars, three different drivers, three sections of route designed to even out any differences in style of right foot application.
BusinessCar is based near Sidcup in Kent, just inside the south-east corner of the M25. From there, we settled on a course toward some of the UK's most congested streets, which would provide stop-start, hellish traffic delays.
The South Circular, or A205, has seen the death of many an estimated arrival time, as many tradesman who have lost what feels like days easing their way through the glamour of the Catford Gyratory and Herne Hill one-way system know.
We headed clockwise around the South Circ, as the locals call it, to a Tesco Car Park opposite Clapham South tube station near Clapham Common, where we'd make the first driver switch ('Stop 1' on the map).
The first section didn't disappoint. The succession of traffic lights and people turning in and out of side roads provided exactly the sort of conditions to test our eco models and give them plenty of chance to show the merits of stop-start systems.
Following a rapid changeover we were off towards the halfway point, just past Kew, over the river and towards the wider, clearer pastures of the North Circular. The A406 is generally dual carriageway, more often than not opening up into three lanes, albeit punctuated by traffic lights, the dreaded five-car-wide Hanger Lane Gyratory and other delights. It's also mainly 50mph, giving us plenty of opportunity to cruise at an economical speed.
Or so we'd thought. As it turned out, the wide, open, A406 was as queue-tastic as the South Circular, due largely to a truck driver who hadn't spotted a red light, resulting in a rather messy Audi A4 Avant - now significantly shorter and less pretty than the manufacturer intended - and queuing traffic stretching back a couple of miles.
But once it cleared, it really cleared and the top quarter of our circle sailed by at a steady 50mph, avoiding the wrath of a succession of speed cameras.
The North Circular takes you back round to the River Thames via the quaint Woolwich ferry. By this time we'd regrouped outside a Currys store in Beckton, just north of the river, for a change around ('Stop 2') before the final push towards the office, or at least the BP petrol station near HQ for a re-brimming of the tanks.
The subsequent calculations would give us some conclusions about the merits of the three different approaches to offering low-CO2 company cars.
If you ignore the official figures, the most impressive car here by some distance, according to our results table above, is the Insight. It was the only one not to break its claimed urban fuel consumption figure, but it was the most economical by a clear 2mpg, and, thanks to the price gap between petrol and diesel, cost 64p less to complete the 60-mile circuit. The flip-side is that the significantly more powerful 1-series is very close on fuel consumption, although handicapped by the extra cost of diesel.
But the Auris was the one that made the biggest improvement on its claimed urban figure. Although the economy was a distance from its rivals, frequent use of the stop-start system meant a 111.3% improvement on the claimed urban figure was the result.
Continued on page 2
|Swap to hybrids? The results|
|Claimed urban mpg||61.4||52.3||39.8|
|Our achieved mpg||56.1||53.9||44.3|
|% of claimed figure achieved||91.4%|| 103.1%||111.3%|
|Cost of 60-mile journey (petrol 90.9p/diesel 98.0p)||£4.42 ||£5.08||£5.51|