[Westen86]

I am no expert on this, but from all the digging Ive done on oil for this chassis, 10w50 is ok to run in this car. Many have gone the 5w30 route for daily driving. Some even 5w40 or 0w40, especially when boosted. In one make races, or GT endurance cars, Toyota had them running 10w60 racing oil. If you beat on the car as much as you say, 10w50 seems just fine. DO NOT keep running it in cold weather. Youre in Poland so 5 degrees Celsius or less. If you are often driving when its below 5*C, you may want to switch to a 5w40. And do not beat on it when the engine is cold. Get 40*C in the oil first.