NOT so long ago just about every estate car at the motorway services would pull up at the black pump for a refuel.
But times are changing and reps, like other motoring mortals, are moving over from diesel to petrol following the well-documented Dieselgate scandal.
Keeping pace with events is the key to survival in the motor industry as Vauxhall, which is now back in profit, knows full well.
So it is unsurprising that a recent introduction to the Insignia range is the 1.6-litre turbo petrol Sports Tourer, a punchy 198bhp load carrier that's easy on the wallet when it comes to fuel.
The Sports Tourer starts off with a big advantage - not only is it spacious and practical but it's unquestionably one of the best looking load-carriers on the road with well proportioned lines and a sleek, sporty styling.
Considering the huge reserves of performance, economy is better than expected. It notches up 42.2mpg combined and while this doesn't match that of a diesel equivalent, it's a big improvement over the last generation petrol units with similar performance.
Translated into normal driving, ie typically thrashing up and down motorways, it means most owners will be squeezing close to 40 miles out of every gallon.
A big benefit is the added refinement of a petrol unit. Mechanical noise is little more than a murmur and the streamlined shape reduces wind noise to negligible proportions, making the cabin a calm and relaxing space.
Coupled to a six-speed automatic gearbox with smooth changes, the Sports Tourer has the necessary ingredients to make it a natural mile-eater.
Acceleration is eager enough with 62mph coming up in less than eight seconds. But it's the mid-range grunt that really makes a difference especially for overtaking. Only when the engine is pushed towards the red line does its note approach harshness.
Low profile rubber on generously wide alloys adds to the cornering ability of the Insignia which handles tidily and isn't easily disturbed by poor road surfaces. Body roll is kept to a minimum even during enthusiastic cornering.
The low sweeping body disguises the fact that this is a roomy beast of burden. With the rear seat in place there's space for 560 litres of cargo and if you need more room the back row folds and splits three ways.
Legroom is generous front and back, and despite the rakish lines there's ample headroom in the rear for a six-footer.
The restyled cabin is easier on the eye with high grade plastic mouldings and well positioned dials and switchgear. It's not such a classy environment as an Audi or a Merc but a definite improvement over previous insignias.
There's plenty of standard kit on board the Elite versions tested, including sat nav, seven speaker audio system, leather seat facings, dual zone climate control, heated front seats and rain sensitive wipers.