I think they mean economy as in cost (money). You can make a powerful inexpensive engine but it will have a worse emissions profile, or a powerful expensive engine that has a better emissions profile. But you don't get a powerful, inexpensive engine that also has a good emissions profile.
Excellent engine, but no green emissions sticker in Europe.
Lifetime of 500,000km (300k miles) and more if treated right, fuel economy 6.5l/100km (36mpg), and can pull a small trailer with a bit of tuning.
You can find it in almost all Volkswagens of the 1995-2005 era, as well as in a bunch of Audis, Seats, etc.