I'm have 6000 miles on my Ninja 500R and I've been using Chevron 10W-40 and I'm planning to switch to Synthetic on the next oil change. I think the recommended oil weight is 10W40 to 20w50 (right?) These Synthetic seems to be quite different as far as these number goes. So I'm debating what I should use, what do you think?
Mobil 1 Motor Oil SuperSyn 5W-30 ($2.5 @costco)
Mobil 1 Motor Oil SuperSyn 10W-30 ($2.5 @costco)
Mobil 1 Motor Oil SuperSyn 15W-50 ($2.5 @costco)
OR
Shell Rotella T Synthetic 5W-40 ($4.xx @walmart)
Shell Rotella T Synthetic 15W-40 ($? @walmart)
Mobil 1 Motor Oil SuperSyn 5W-30 ($2.5 @costco)
Mobil 1 Motor Oil SuperSyn 10W-30 ($2.5 @costco)
Mobil 1 Motor Oil SuperSyn 15W-50 ($2.5 @costco)
OR
Shell Rotella T Synthetic 5W-40 ($4.xx @walmart)
Shell Rotella T Synthetic 15W-40 ($? @walmart)