Originally Posted by m 135
I know the air-filters are placed at the rear on the 50i,which also makes them hard to change,where as the M versions are toward the front,making it easy to get to if you want after market filters.
I wonder if the different location on the 50i is a negative for air-flow like you mentioned
Could be...I need to look under the hood and see if there's any restriction point. I remember the X5M having two big air boxes right up front.
In the past I had a 987 Boxster S. The air intake was on the side, and it had a restrictor plate that literally had a gap a finger-width wide allowing air in. I removed it and gained an easy 15 hp up top. Not saying there is something similar here, but manufacturers have been known to do this kind of thing.
2016 F-type R Ammonite gray/red
2011 Nissan GTR Red/black - HP Logic tune/midpipe
2013 BMW X5 50i M-sport M-performance Alpine white/black
Gone but not forgotten: '12 X5M, '07 AM SuperVantage, '05 Boxster S, '01 BMW M3,...