Originally Posted by
MetroMPG
I haven't seen any
carefully documented fuel economy gains from just adding a turbo. Generally, the automaker's turbo/efficiency approach as you say is through downsizing the engine, and/or going with numerically lower gearing.
On the gearing: I actually swapped in a taller (numerically smaller) final drive ratio in my 1.0L Metro/Firefly. Fuel economy improved 5% at 80 km/h (~50 mph). Acceleration suffered, but I don't mind. Theoretically, I could have put a small turbo on it to re-gain the acceleration, and when staying out of boost also preserve the MPG gain.
Mitsu could offer a turbo 1.0 with taller gearing than the 1.2 which would outperform the 1.2 in both acceleration & fuel economy.
(Then the speed fanatics could swap their taller trans with the shorter 1.2L economy fanatics trans and everybody's happy.
)
It's fun to speculate.
Bring back the Twin Stick!!
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View my fuel log 2015 Mirage ES 1.2 automatic: 40.5 mpg (US) ... 17.2 km/L ... 5.8 L/100 km ... 48.6 mpg (Imp)