I have never had a problem with any oil filters or oil with the dealer, intake kits can invade with your warranty,they dont do much unless you like the look & noise they make . I believe you can use a K&N stock filter replacement and be ok. I always put my stock air intake on when I was still under warranty if I had to take it to the dealer, smog check, etc....

 

For hyper-miling tips, try ecomodder.com-"100 tips for better gas mileage"

I'd advise you don't worry about a chip till your truck is out of warranty, you don't want to give the dealer any more excuses than they already have to weasel out of their warranty obligations.

I waited till my truck was out of warranty before I got new rims, programmer, etc. There's plenty you can do while the truck is new, but always see if any mod is going to affect the warranty , first.

Many people think Mobil 1's a good idea, if you check, I don't think it will affect your warranty.