# Chevrolet Squeezes An Extra 2 MPG Out Of The Cruze



## 70AARCUDA (Nov 14, 2010)

...see also: http://www.cruzetalk.com/forum/27-fuel-economy/2035-chevy-slows-cruze-boost-2012-mpg.html


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## usbp456 (May 24, 2011)

Ive heard that this will make the 2012 model "slow". Can anyone collaborate on that? And what does "slow" mean?


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## 70AARCUDA (Nov 14, 2010)

...drag racers use "low" axle ratios to increase engine speed (and thus power), ie: they typically like *4.11:1* axles, while stock axles would be around 3.23:1 (auto) or 3.55:1 (manual). This makes the engine produce _more_ revolutions per mile, which equates to *quicker* acceleration; going the *opposite* direction will make the engine produce _fewer_ revolutions per mile and thus yield *slower* acceleration:

POWER = "how fast" WORK is PERFORMED...so, _more_ rpm = _more_ power per _rate of time_ (acceleration).

...dropping the A6 (6T40) axle-ratio from *3.87:1* (2011) down to *3.53:1* (2012) will reduce engine speed by about 200 rpm --roughly 8% -- at 60 mph:

2011 AXLE: 3.87:1 = 2,295 rpm @ 60 mph
2012 AXLE: 3.53:1 = 2,094 rpm @ 60 mph


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