THE easiest way to economical driving is keep a light right foot on the throttle - it's free and you'll save fuel every inch of the journey.
Trouble is, of course, hardly anyone bothers. Far too busy and in too much of hurry to ease off the gas and go a bit slower, aren't we?
So we look for cars that will give us fuel frugality without asking anything in return - no eye watering purchase price, no trailing charging cables, no lack of performance.
Diesels do the job, especially if you're a driver who piles on the miles. But the smelly fuel has entered a pit of public loathing it probably won't ever recover from.
Or you could buy one of the popular breed of new models with tiny turbocharged petrol powered engines; they return impressive economy and lots of them are good to drive too.
But you can't have both attributes at the same time. Decide when you start the car each morning if it's fun or fuel saving you want today. Put your foot down and economy falls off a cliff. Your choice.
Then there's the radical route - go all electric. No fossil fuel consumption at all, of course, and you'll only need to pay modest amounts for an electric recharge.
But the cars are costly, their range is limited and unless you have a garage or driveway for the charger it is going to be impossible to replenish the battery overnight.
Which brings us to the world of hybrid cars; powered by a mix of conventional petrol engine and electric motor. More specifically today, it brings us to the Hyundai IONIQ.
Or rather, to three of them. For the Korean car maker has charged into the electric arena (sorry) with a trio of machines that look outwardly nearly identical but hide differing degrees of battery assist.
At the top of the range is the entirely battery powered IONIQ Electric (from £29,495) with a claimed range of about 175 miles before you need to find a charge point. You might find its cost and fear of range anxiety enough to put you off.
In which case, consider moving down the price scale to an IONIQ Plug-in (from £27,495) which will take you up to a claimed 31 miles on pure electricity before the petrol engine chimes in. You'll need to charge the battery via a cable but there's no fear of being stranded when the juice runs out.
But there's a still less expensive answer in the hunt for high economy; take a look at the IONIQ Hybrid (from £20,585) and its mix of petrol engine and smaller battery for its electrical assist.
You can't charge the battery; it claims current as you brake or coast along and is a proven way of stretching the mileage from a tank of petrol. Millions of Toyota Prius owners have been doing it for years.
Well, they've now got a serious rival to consider, which gave me 59mpg over several hundred miles and - crucially if you enjoy driving - is fun to punt along.
The Toyota uses a CVT automatic gearbox which doesn't care to be prodded into action in a hurry; the Hyundai's six-speed double clutch automatic is wildly more responsive.
It is also attached to a car that comes very well equipped (with the best sat nav of my experience in the top version) and is smooth riding and quiet too.