Liquefied petroleum gas conversion from diesel simply wasn't a viable proposition as it was too expensive, so fleets would take longer to recover the initial outlay. Now specialist firm LPGDiesel.co.uk has developed a system especially for oil-burning engines and is busy marketing itself in the van sector.
I spent two weeks behind the wheel of a Volkswagen Transporter with a 2.4-litre diesel powerplant which had been converted by the company and rapidly came to the conclusion that any fleet managers who didn't at least investigate the possibility of converting to this green fuel would be failing in their responsibilities.
I very rarely drive any vehicle which is more than six months old, so was surprised when my VW turned up at Fleet Towers to see it sporting a P-plate and 60,000 miles on the clock.
But Bill Kemp, commercial director of Zone 1, the company which imports the conversion kits, soon pointed out that this was the whole point of the exercise - any vehicle new or old can benefit from the extra power and economy that LPG offers.
As it happened, I hadn't driven a Transporter for some time, so was able to renew my acquaintance with this perky performer.
Also as luck would have it, the van was sporting a brand new livery from vehicle wrapping company Optima, which kindly provided me with a set of shots of the decals actually going on.
There is little point pontificating about the merits of LPG in this road test - the simple fact is that Britain's roads are choked up with millions of vehicles spewing out noxious gases into the air and it is up to all of us, whether we like it or not, to try and improve the situation.
And while LPG may not be the panacea for all fleet ills, it not only cuts down on poisonous fumes but can also save fleet costs too, so there seems to be no earthly reason why fleet managers shouldn't try it.
The company can convert anything from a 4x4 pick-up to a lorry at its network of approved centres and prices range from £1,925 to £2,325. Grants are available under the TransportAction PowerShift programme.
Ageing this van may be, but the cab was still smart, solid and functional, just as you'd expect from Volkswagen.
The dash looks as though it is hewn from stone, such is its immense chunkiness -and the driver's seat feels the same.
But after a hundred miles or so, you begin to appreciate that maybe the Germans know a thing or two about seat design and the chair that at first felt like a tombstone, now hugs your figure comfortably.
In the back, a small part of the load area is lost with the addition of the gas tank, but it is a small part indeed. The tank hardly sticks out further than the wheel arch and tucks in behind the driver's seat.
Volkswagen's diesel engine was always a smoothie, but flick the switch over to LPG (a seamless operation) and there is a definite power surge as diesel gives way to gas.
This unit will purr along happily at 90mph all day where legally allowed and with a light clutch, easy-going gearchange and small car-like steering wheel, the driving experience is a pleasant one, even for inexperienced van drivers.
Zone 1 has carried out its own tests on a route which took in Newbury, Andover and Sherborne. Using only diesel fuel and with a Force 3/4 south westerly wind, the fuel usage worked out at 12.14 pence per mile. On the same route using LPG, the cost dropped to 11.01ppm for gas bought at a retail site and 10.61ppm for bunkered fuel.
In the second year of the new millennium, it simply isn't an option to stick our heads in the sand and pretend that problems with the environment will go away — they won't.
And if van fleet managers don't soon jump on the green bandwagon, it looks likely that the Government will start cracking the whip and pushing companies down the green route whether they like it or not. The figures here and the driving impressions speak for themselves — so what are you waiting for?
Verté Automotive: 01276 410330 www.accars.co.uk
Diesel conversions: www.lpgdiesel.co.uk
Grants for LPG conversion: www.est-powershift.org.uk