? I don't know if it's true, but using regular oil for the first oil change is considered better for break in than using synthetic oil, until the second oil change. Then, synthetic would be the way to go... Just the way I understand it.
Excellent point. There are all sorts of theories on break-in and oils, but at the end of the day none of these are supported by anyone that has ever designed or been responsible for the worldwide maintenance of a single Subaru motor, let alone hundreds of thousands of Subaru motors.As far as I know, WRXs are shipped from the factory with synthetic oil….right?
So if "regular" oil is so much better for break-in, why wouldn't Subaru ship the cars with that oil?
Subaru only recently updated the requirement for synthetic oils. It could be that your manual was simply printed before Subaru published the requirement. That being said, synthetic oils have great benefits over mineral oil for any turbocharged car -- specifically the film strength under extreme heat. Though, that's only after the break-in period...Which brings up another question. My manual doesn't specify synthetic oil, it just says that synthetic oil CAN be used. I have heard and read that the wrx needs synthetic oil but am curious why the manual doesn't specify it.
and this is all absolutely correct for a fresh virgin engine.. But our engines have already had the initial run in haven't they? Every engine I've ever BUILT fresh I followed the non-syth rules for the first 100mi or so, after that changed over to full synthetic. The scoobie I bought new and ran the original oil till the first oil change interval (3750mi) and then switched to synthetic. So far over 60k mi clocked and no consumption/burning issues. I'd go to say it broke in pretty well.Engine Break In Procedure According to Ron at Raw Performance- Great Read - Subaru Impreza WRX STI Forums: IWSTI.com
"Make sure the engine is full of new non-synthetic oil(see oil suggestions below) and that the oil filter is also full of oil and hand tightened to the engine."
CobbTuning.com - How To Break-in Your Newly Built Engine v1.03
"Never use synthetic engine oil during this process, use a straight weight, non-synthetic, non-detergent engine oil. You want friction at this point; use an SAE30 oil, non-synthetic, no detergents, etc."
"During the break-in process, we recommend using a high quality API SJ or newer mineral 20W-50 engine
oil. We also recommend using a genuine Subaru oil filter. Do NOT use a synthetic or synthetic blend
during the break-in process"
Crawford Performance - Subaru, Scion, Hyundai Performance
" Break-in the motor for 1000miles/1600km using regular (non-synthetic) motor oil"
Obviously at 1K it's too late for the OP but it was just to illustrate that it is a common practice. Also Amsoil,Royal Purple,Joe Gibbs Racing and a few other companies make an actual "break in" oil. I'm pretty sure Subaru does not break in the motor at the factory.and this is all absolutely correct for a fresh virgin engine.. But our engines have already had the initial run in haven't they?
Maybe so, but SOA is the one that will honor the warranty in the states, so I would adhere to that recommendation.SOC (Canada) don't care what you use as long as it meets the specs in the Owner's Manual and I'm pretty sure that it's the same engine that the US gets.