I just bought a 2002 Honda 115hp and would like to change the oil. I need an opinion on what motor oil to use. The motor has about 320 hours on it. I don't know what the previous owner used. The manual states 10W30 API SE,SH. I looked at my Castrol GTX motor oil that I use on my car and it seems it has same grades in the oil. Went to Markham Outdoor Power here in Markham and they tried to sell me Honda 10W30 as a marine oil. They know their stuff, but it was a bit much paying almost $8.00 per litre and it was not the FC-W grade either. I could not tell the difference between the Castrol automotive oil or the Honda. On the back of the label they both have the same grade specs. Also, I read some articles to go with Mobil 1 synthetic, but a bit scared since I don't know what the previous owner used. Any help is appreciated. Thanks.
