I just recently sold my wife's 1999 Toyota Avalon with the 3.0L V-6 that I think is identical to your Camry's. It was a low mile car (85,000 miles in 11 years). After the first oil change we used exclusively synthetic starting with Mobil 1 and ending up (and sticking with) Pennzoil Platinum for the duration of our ownership. We used whatever inexpensive oil filter the oil change place was using but (now that I know more) I would recommend using a mid-premium filter like a Napa Gold, Purolator Pure 1 or similar. We ran OCI's of 5K miles regardless of time and never had any oil or sludge related issues. It developed a small head gasket leak, which I had repaired, right before we sold it. It's hard to say for sure, but I do not think that was an oil related issue. Hope helpful, good luck.