I've got a 2001 toyota V-6. Have run 5-30 dino for 1st 30K miles. Not sure of the specific brands used. Thinking of switching to sythetic oil. Can anyone tell me what the true benefits to full syntheic oil are? Are there any brands better than others? I was thinking of going w/ Mobil 1, mostly because of what I've read her and it is readily available. The other factor to consider is that I just learned that the engine in the toyota may be one of the engines with a defect that is known to have oil sludge problems. So I would like to use an oil that will be less likely to form sludge. Thanks for your insight.