i know in our case we could not break in the engine on full
synthetic the rings wont seat and it will have blowby like crazy
i really dont have a clue exept that its tough to get a engine broke in ,we are running straight 30w for break in we only have maybe 4 or 5 hours on our engine so it could be a while till we put in the good stuff ,like i siad we raced on this stuff for years and it works saved our engine from blowing from overheating
our builder said we would have Cooked dino
oil and lost it. when we took the short block apart it looked brand new inside replaced the head won on it the next several weekends
