Hey all, I know these 'which oil' questions are becoming tedious but I've actually searched the posts and can't find anything specifically relating to what I'm wondering. I've got a '83 XL600R and was wondering if the extra $30 I've seen the fully synthetic 10W 40 oil for is worth it? I've posted this new topic in the case that older single cylinder engines really don't need fully synthetic stuff and I would just be wasting my money. I also saw some BelRay stuff advertised as thumper oil - would there actually be any difference between this and alternate oils other than what's printed on the container? What do people recommend? Cheers.