[Neusser]

Originally Posted by pbonsalb

You write that the 550 is less dynamic, whatever that means, and that it is only good for straight line acceleration, which does not interest you. I’d like to see a track test of both and my guess is the 550i would spank the 540i in a straight line and around the track. Both the 540i and the 550i are mid size luxury cruisers.

What we know for a fact is that one car has 55% of its weight over the front axle (about 54% is usually considered a critical threshold for anything that purports to be sporting), but runs the same tire size and track width as the car that doesn't. Even the brakes are the same with the M pack.

Balance makes a driver's car a driver's car. The 550 is not only less dynamic, it is less dynamic in a way that you can't change once you near the limits of grip--add in AWD and you have bags of understeer.

[pbonsalb]

Maybe the 530i is the most dynamic 5 series? You should get one.

[DrVenture]

Thanks for the info. I missed that it was only for the 540. The reflective tape is a good thought. Wrapping the cat piping is also a good idea.

[pbonsalb]

I read that one should not wrap cats — that it could make them too hot internally, so I wrapped only the pile in and out. Then while changing the oil on my 2021 Cayenne S, I noticed the Porsche cats in the hot V are fully wrapped from the factory, though with that thin quilted metal sheet wrap.