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Old 10-21-2020, 12:53 PM   #4 (permalink)
MetroMPG
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Join Date: Nov 2007
Location: 1000 Islands, Ontario, Canada
Posts: 22,527

Blackfly - '98 Geo Metro
Team Metro
Last 3: 70.09 mpg (US)

MPGiata - '90 Mazda Miata
90 day: 54.46 mpg (US)

Even Fancier Metro - '14 Mitsubishi Mirage top spec
90 day: 70.75 mpg (US)

Appliance car Mirage - '14 Mitsubishi Mirage ES (base)
90 day: 62.14 mpg (US)
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Nice!

The cam: was that for added power, or to shift the torque curve down to make highway cruising more efficient?

Oldsmobile offered (or at least tested) such a cam in the 60's:

Quote:
...the camshaft is the key. Intake duration is reduced from 286 to 250', and from 286 to 264' on exhaust. Overlap is reduced from 58 to 36', and lift is reduced from 0.472 in. on the 4-4-2 camshaft to 0.435 on the special ... camshaft.

The vital point of maximum torque is dropped from 3600 to 2600 rpm. - source
Unfortunately, the source web page is now offline. But it referenced a magazine article about the engine.


Lower lift & duration is the design of the special economy cam in the Geo Metro XFi as well.
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