Roto-Fab filter, oiled or dry & why?
 

Looking at this CAI, certain website asks if choosing oiled or dry filter (dry is a $16 upgrade). Which filter & why? Thanks

I think it comes down to personal preference and whether or not you want to mess with washing, drying, and oiling a K&N type filter or just cleaning and drying a dry filter. There is also a concern over oil accumulation in the Mass Air, but haven't seen any reported incidences of this on the ZL1. It's also easy to over oil a K&N type filter.

I don't think K&N filters trap as much dirt as they claim vs a dry filter. You may have seen the display where a k&N filter and a dry filter are in a box with a fan a ping pong ball and the ping pong ball is lifted by the fan on the k&N side, while it is stationary on the paper filter side. If you look closely at the cotton gauze in the K&N filter, you'll notice tiny holes in the gauze. K&N claims the oil on the filter traps the contaminants, but I think a lot of them get through and show up a s higher silica content when an oil analysis is performed.

Oiled filters, because they're oiled, can run with less filter material, which means better airflow. This of course leads to a bit more efficiency, and more power (though really negligible compared to the dry). Oiled filters require maintenance when it comes to cleaning, ie: washing, letting dry, then re-oiling.

Dry filters are thick paper filters typically and though they block out debris more than oiled filters typically do, because they're thicker, they're less efficient, which results in a bit less power. What they really are good for is less maintenance. Cleaning just involves removing from the car, and I typically take a paint brush to it and get all the dirt out of it. I never take high pressured air to it, this can lead to punctures in the filter material which of course leads to very bad news.

Personally I'd still go with oiled filters, I don't mind the extra maintenance.

Dry filters will not quite flow as well as oiled filters and will continually flow less and less efficiently throughout their life span. I prefer and recommend the oiled filter. Please feel free to call, PM or email me anytime with questions.

Best regards,

Tyler
888-308-6007

I personally prefer dry filters. They filter better. Who cares about an extra 1-2 hp when it comes to filtering. I'd rather have a better filter. Just have to clean it once a month. Takes about 2 minutes.

When I bought my Roto-fab for my SS back in '09 I bought directly from Roto-fab. I bought with a dry filter. They said for stock NA applications the difference was minor but with FI motors the added restriction would reduce HP gains significantly.

On a ZL1 I would use the oiled filter.

Edit: I owned both filter types from Roto-fab.

Stock SS = dry filter not much difference. Less maintance

ZL1 = oiled filter due to being supercharged.

i sent a note to Rotofab asking for their take on oiled versus dry and got this reply:

The dry filter is preferred by those concerned about the possibility of contaminating their MAF sensor with oil. The dry filter has slightly better filtration also and is a better choice if you do a lot of driving on dusty roads. The oil version is our standard filter. It makes a little more power than the dry version. Either filter should last for the life of your car. Periodic cleaning is required.
Thanks,
Jennifer
Roto-fab LLC
260-375-4480

boils down to personal choice