When you add a supercharger to a truck or large SUV that could well be towing something, the first thing to do is make sure the owner knows not to get a K&N filter and, if he does, not to over oil it when cleaning it.
I told the TRD rep. about that when I did the first supercharger install on a tundra on the east coast with him after I noticed the very large trailer towing equipment in the truck which probably meant a heavy trailer and predicted the truck would come back with a blown up engine.
It came back a few weeks later with blown up engine I had to change under warranty........which pays about 1/3 of what a customer pay engine change does.......and I still had to switch over the supercharger stuff for free.
A few weeks later, the next supercharger install came with freshly printed stickers stating not to use K&N filters.
Certain mass air flow sensors have a hot wire or film that get's hot enough to cause any oil from the filter on them to coat the wire with ash.......which insulates the wire from the airflow meaning it requires less current/voltate/duty cycle to maintain it's temperature.
This causes a lean condition.
The lean condition doesn't hurt until you run lean under boost.
On our tundra, the owner cleaned and oiled up the filter right after the supercharger installation and pulled a trailer just under the maximum weight across the state of florida at like 80mph which meant he was under boost the entire way with a lean mixture.
I pulled the freeze frame data and it showed the data from when the failure occurred yet the dealership decided on a "goodwill warranty".....which screwed me.
This was in 2001 and you now have K&N doing spin control and a lot of people thinking it was the causation of everything that ails thier cars.
Any addition of a supercharger or turbocharger requires a lot more research into how the owner drives it and I've gone as far as scouring forums to find a few trouble owners are bragging how they made a dealership pay for something they broke at the drag strip.
Now I do the research as early on as possible and it's saved me more than a few "freebie" warranty claims when I found facebook pictures of cars at the drag strip or posts concerning massive abuses of thier cars.
One was a smoked transmission on a lexus IS-F when I found remnants of the white paint they use to write a number into the back window of your car at the drag strip which prompted me to check further and find a pic of a multi-port 300 shot nitrous oxide system on the car.....have the pic but can't find it.
I doubt any of the owners that I do builds for can even set their own tire pressure let alone clean and oil a filter, this owner has been told NO towing of anything at anytime. I told the parts manager to stock front and rear axles and drive shafts, this dude is going to try and lite all 4 wheels up I have a feeling
I have been using K&N stuff for years and a little oil is all you need on them. I don't recommend them to any non-car guy to use, but people still use them and I sell a ton of MAF sensors to the ones that do. I don't like K&N filters for street use they need to be inspected often and cleaned properly and oiled more that people realize.
I have surfed youtube and seen some of our customers doing some stupid crap. I have to say one thing I have only done 1 warranty clutch on the high end stuff and it was the owners son's demo, you know how that goes
Everything else that we install get's covered no matter what unless Ford gets involved than it is a crap shoot on if it's cash or covered.
I had a GT500 with a motorsport super charger upgrade on it come back with 400+ miles and the clutch was smoked I mean the flywheel was blue, the dad bought his 18 year old son a grad gift
needless to say 4k later he paid the bill and never seen that car again, probably got totaled on the way home.