Turbo Boost and FE

[GasSavers_Hal9000]

Originally Posted by aych

so if i say i have 2 identical cars, except one has a turbo and one does not. Who'll get the better FE if driven identically?

I'd say it totally depends on the driver. The downside of turbochargers from an FE standpoint is that it makes it much more tempting to have fun... More fun to go zipping away from lights, accelerate around slow traffic, or just get on the gas to hear the sound of the turbo or the beautiful exhaust note. If you're like 99% of the population, even if the turbo engine would do better when driven conservatively, you'll end up giving in to temptation and driving harder than with the NA car (ruining your mileage in the process). The human factor is probably the biggie here.

The only way I can see to solve that problem would be to limit the amount of boost the turbo produces (thus limiting the power on tap) to a very low number.