> > > andrew strasfogel wrote: > > > > > > Folow-up question: With the turbo boost back to normal and > > > power restored in all gears and at all speeds, will this > > > negatively effect my fuel economy?
> > On Fri, Jul 15, 2011 at 4:08 PM, Fmiser <fmi...@gmail.com> > > wrote: > > > > No. It will improve. Because the turbo increases the > > efficiency of the engine. > > > > Unless you use full power quite often. :) > andrew strasfogel wrote: > I will now be tempted to, since the engine is now resposive to > my foot pressure. :) Well, it's still a _very_ good idea to make the engine work hard often enough to keep it clean. But that can be, "climb the big hill in 3rd gear, wide open" every week or two. But at normal cruise, the turbo is recovering some of the waste heat from the engine and using it to stuff more air in. It's this recovery of exhaust heat that causes the overall efficiency to increase. The engine (at least a correctly working Mercedes) does not allow more fuel to be injected than there is air to burn it. If there is no clouds of black smoke, then this is working. So with low boost, there will be less fuel used - but more waste heat. With the turbo working properly, the exhaust heat is used to force air into the engine. This means that the maximum fuel that _can_ be burned is greater - so the maximum power is also greater. But with the engine at cruise, it's the reclamation of heat that provides the fuel economy increase. And that's why it's possible for the outrageous claim to be true: more-power != less-mpg -- Philip _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
