[ar5boosted]

Originally Posted by Mustang Matt

When I think of cruising, I am imagining cruise control set at 60 mph on a road trip.

The thing about turbo cars is that while the wastegate is near 0 vacuum it's open and not building boost

I'm pretty sure that the graduation of the wastegate on small-efficient-turbo cars is done a little different than on traditional n/a cars.

I'm sure that some level of boost to help air into the combustion chambers is available well before 0 vacuum. I think that the Europeans have done a bit of tuning on the wastegate controllers to make them better/more-fuel-efficient for 60-80mph cruising.

I'm just requoting some common industry discussion here so that I don't say the wrong thing :

"The Bottom Line
So just how much fuel can a turbocharged gas engine save? Well, that depends, of course, on what you're comparing it to and whom you ask. It's safe to say, however, that a small, modern, gasoline-turbo engine will save about 8 to 10 percent over a larger engine that makes similar power and torque. There are side benefits to turbocharging small engines too--such as reduced weight. Ford's Brett Hinds says that the upcoming EcoBoost V6 is 30 pounds lighter than a V8. That may not sound like much, but every bit counts. And that's especially true, as automakers will continue to hunt for even more fuel efficiency in the coming years."

Top 5 Turbocharger Tech Innovations: The Truth about Fuel-Sipping Turbos