The great oil debate!
I've had this discussion so many times. Everyone seems to have a different opinion. Here's mine (based on a lot of reading and discussions over the years and running a number of XT600s over many tens of thousands of miles)
Synthetic is at best a waste of money and unless it is motorcycle specific you risk clutch slipping problems.
I've used semi synthetic or synthetic fortified for many tens of thousands of miles no problem.
If you're going to experience temps near zero degrees at any point, you should use 10W 40. Otherwise, 15 W 40 is probably better for higher temps.
Remember to measure the quantity your putting in carefully - you won't get the total quantity your putting in until the engine's run for a minute.
Mark
|