Quote:
Originally Posted by Gangplank
Yes but I'm sure you agree that the motor n55 and non progressive front springs are a bigger upgrade that light clusters.  |
I had a 2008 135i with the N54 and honestly, didn't notice a difference in power. The stock N55 sounded a little better imo. All I know is the N54 is better for tuning and high hp, and the N55 is supposed to be more reliable.
In 2011 BMW changed the rear springs on the 135i from progressive to linear springs. The rest of the suspension went unchanged.