I too, also bought a new 2003 Tacoma this summer, the Xtra Cab 4x4 w/the 2.7L I4 engine.
I did it's first oil and filter change at 1000 miles, then 3000 miles, and just recently, 5000 miles, at which time, I made the switch to synthetic oil, Mobil 1 5W-30. I'll start to do my oil and filter change now every 5000 miles.
You'll hear suggestions on when to switch to synthetic, from the first oil change, at 1000 miles, all the way up to 10,000 miles, which Toyota mechanics I've talked to, recommend. I simply took the the average, and went for 5000 miles.
The first oil change is very important, as I see it, mainly to flush the engine of any possible machining chips and casting sand, due to it's manufacture, and metal particles, due to it's being broken in.
I also changed all the powertrain oils (front and rear differential, transfer case, and manual transmission) at 5000 miles, for the same reasons as the first engine oil change. I put Mobil 1 gear oil in both the transmission and the rear differential, and regular dino gear oil in the front differental and the transfer case. I stayed w/the dino oil w/the front differental and the transfer case, because they only have around 100 miles on them, while the rest of the powertrain, the transmission and rear differential, has 5000 miles. I'll switch everything over to synthetic next year.
As for the oil filter, I use the Toyota/Lexus 90915-20004 oil filter, which fits w/o any problems on the 2.7L I4. I don't know if it'll fit the 2.4L I4. Do a search here on it and you'll see why I picked it rather than the standard Toyota recommended 08922-02011 for the 2.7L.
[ September 12, 2003, 11:01 PM: Message edited by: GoHack ]