Originally Posted By: Spdfrk1990
Originally Posted By: Vlad_the_Russian
Do your vehicle a huge favor - use the best oil from the start. Like this here. 0w30 or 0w40 is what I would recommend, but 5w30 is fine as well. 0w30 and 0w40 just have a wider range of operating temperatures.
I have not read anything bad about Castrol Edge and been using it for awhile now in my other vehicles. Using the 5w30 to stick to what the manual calls for so I dont have any issues with warranty if I ever have engine trouble.
When it comes to warranty - they will only need proof that the oil changes were done in timely manner (receipts) and they might test the viscosity. When it comes to viscosity test - they will only be able to test for the operating viscosity. So 0w30, 5w30, 10w30, 15w30, 20w30, 25w30, SAE30 will all look the same on their warranty testing. Based on this I would definitely find the MOST ROBUST oil in 30 grade available for the STI. RedLine 0w30 or 5w30 or even 10w30 will most definitely eliminate any oil-related issues for many years/miles to come. And after warranty is over - you could easily stretch it out to 10k OCI, like many here do with amazing UOA results on RedLine oils. Unless you do a lot of track days.
Castrol oils have their additive levels slashed by the API certifications. High performance engines NEED those additives. Redline oils have one of the highest amounts of additives to battle anything that happens inside an engine.
Think of it as boxer vs MMA fighter. Boxer with boxer gloves and boxing rules will not last long in a MMA cage vs an MMA fighter who follows MMA rules during a fight, since boxers are limited to only arms and upper body, while MMA fighters can and will use their whole body to the fullest potential in a fight.