It shouldn't be voided as long as you stick with products that are approved for your vehicle and as long as you keep receipts and mileage with it. That's what I have been doing. I would still consult with your warranty provider first though. The dealer is a rip because they have to pay all the staff, plus insurance through the roof, chemical pick up fee's, blah, blah,blah. Do it yourself and return the used oil to pep boys. This took me about 30 or 45 minutes to do in my garage - well worth saving several hundred dollars in my book!