Originally Posted by catalina38;[URL="tel:20451516"
[/URL]]I did a few long rides (6000 miles) with identical 2010 990
R's same exhaust, stock R map with the unifilter prefilter on one and the other with stock snorkle. They got nearly identical gas mileage, no noticeable difference in performance. The bike with the prefilter required it to be cleaned several times during those rides but kept the main filter cleaner longer. After the 6000 miles the more frequent maintenance became a PITA. More work overall for not much benefit. After this first hand experience I decided not to install one and he was going to remove it at the next filter replacement. YMMV.
I put the UNI prefilter on 2 years ago. Stock filter still in place.
I had nothing to compare with,
but it did not seem faster/better, nor any mileage difference.
Intake sounded slightly noisier in a good way,
but the hassle factor of needing more cleaning, more often, is not really worth it.
I will either remove it or clean it, and not re-oil it.