well, i only suggest he use engine restore if he start leaking badly due to the good clean-up done by synthetic oil. i know people who use engine restore for slightly used cars too. my neighbor got a 2001 S2000 with 3000 miles on it, and he just put a bottle of that restore chemical in even though he use mobil 1 0W30. he said he wants to make sure the engine last as long as possible since it has to work harder than other large size engine to produce good accelaration.

i'll probably put a bottle of that stuff in my engine when it gets 40 thousands miles. for florida, 10W30 is the best. any place with temperature reaching 40 and below would see the advantage of 5W30 or even 0W30. the new mobil 1 supersyn is made for warm and slightly cold climate and it last longer than the previous mobil 1. however, it doesn't offer the same cold-start protection as the regular synthetic mobil 1. the 1 oil with the best pour point i have seen on the web is from chevron, it has -72 or -76 degree F of pour point. that's good stuff, but it only last about 10 thousands miles. mobil 1 last 15k miles and has pour point of -65. the new supersyn has a pour point of -54 and last 20k miles. i found this information on the back of the bottle.