http://www.blinkbits.com/en_wikifeeds/GDI_Engine

Last week I was in Europe and got to drive a
VW Golf 2005 direct injected gas engine tanked with sulphur free gasoline.
Unfortunately I wasnt able to check the fuel consumption, but I was told by the owner it was
doing 20-25 % better than his previous Golf
which has the indirect injection system we are used to.
Also noticed while the car was idling the cooling fan did not start. This is because the fuel-air mix
is as low as 1:64 versus 1:14.7 for the unefficient manifold injected engine.
In hybrid cars this inefficiency is offset by letting
the battery run the car when moving in slow traffic or standing. However this comes at a premium price($3000 and up). Direct injected
engines can do much the same, but with a fraction of the price (less than $800). However
in order to run lean the DI engine need sulphur
free gas coming is September this year.
Another advantage with DI is that engine runs
much cleaner and oil change intervals can be
doubled. The japanese had these cars and the
sulphur free gas for many years. Some European countries the last few years. Are we wasting our money on hybrids in order to save
maybe 5-10% over the DI.
Read above link.