Then – Burning dino juice
Setting fire to stuff that comes out of the ground to make a car move will one day seem like a very silly thing to do. But even now, it's still the dominant technology but back in the 1970s, petrol and diesel engines were the only options.
Even worse, back then smog-reducing technologies like catalytic converters and urea injection for diesel engines weren't even commonplace, though it's also true the dirty diesels were much less common in passenger cars.
Now – Hydrogen fuel cells and EVs
OK, there's just two proper hydrogen car on sale in the UK, the Toyota Mirai and Hyundai ix35 (Tucson for the US), and who knows if hydrogen power is indeed the future of motoring. But it's the figurehead of a wide range newly-powered vehicles out there now, hybrid and pure-electric cars in all shapes and sizes.
Electric vehicles (EV) with range extender capabilities combine a fairly big battery with a small range-extending combustion engine, like the BMW i3, or the plug-in hybrid electric (PHEV) Opel Ampera, look like the best compromises for now.
But if you can afford it, Tesla has just tweaked its Model S for maximum range, and it will now do over 300 miles on a single charge. There's also the Nissan Leaf for those with a lower budget.