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Old 07-25-2006, 11:21 PM   #1
Scooby Newbie
Member#: 64528
Join Date: Jun 2004
Default Port-Polish heads vs Fuel efficiency

How does port polish heads affect fuel efficiency and emissions
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Old 07-26-2006, 12:51 AM   #2
Patrick Olsen
NASIOC Supporter
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
1997 Legacy 2.5GT
1996 Impreza coupe


It make to better.
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Old 07-26-2006, 11:10 AM   #3
Matt Monson
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Member#: 832
Join Date: Jan 2000
Chapter/Region: RMIC
Location: Teh Ghetto Garage, CO
99 2.5RS, '85 911
'73 914 and 2012 BRZ


When I installed my Pnp'd heads I saw about a 2mpg increase from my previous set up. With just the spicy cams, my car ran super duper rich above 4500rpm. With the addition of the heads and greater air flow, my AF's came down to what I would consider a marginally rich ratio, and thus the better gas mileage.

I passed emissions with no problems with the cams 2 years ago. I have to test again in about 6 weeks, and it will be with the heads installed. I will report back once I do, but I fully expect the car to still pass...
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