Hey group, happy new year to you all!

Here's an 'in my opinion' thread, would love further input.

I have used every motor oil known to man in my bikes. My work vans, Civic SIR and RV get Mobil 1 full synthetic. The cold wear and shear characteristics of synthetic oils is apparently better than old dinosaur oil- my previous SI went 525,000kms. 10,000 Kim's between changes. That being said...

My '08 CBR ran full synth (Motul 300V) and all seemed to be well in there.

My older bikes (all 80's era Hondas, don't own some anymore, current 600F1 and 1000F, also VFR, XL600, XR400R et al) do not appear to enjoy full synth or semi synth (usually Motul products).

I've used different oils in my 600F1, 10 oil changes in 53k. I always used Castrol GP 10w40- great stuff. The last three changes I used Motul 300V...engine was 'thrashier sounding', CCT made a wee bit of noise at idle, a little more valve clatter. Switched back to Castrol GP and the engine was quiet almost immediately with zero CCT noise. So, in my humble opinion, as these machines were speced for good ol dinosaur oil, they like it better. Mine seem to. I change oil a lot so the extended service interval of synth is a non starter. Bikes are all maintained to a high standard.

Maybe the engine tolerances in my previous '08 CBR were to a higher spec so synth was mandatory.

If you've got a wee bit of CCT noise and running synth, give old Castrol GP a try. Can't hurt!

If any members are chemistry/oil types would love your feedback!

 

I run an ape cct, so oil has no bearing on my rattle. When I got my first F1, the owner had been using that motomaster motorcycle crap. Bike always seemed to run a little hot, didn't shift well and was really rattly. Switched to Rotella dino and made a huge difference in shifting, and maybe lowered the temp a bit? But at the same time I switched to an APE, so no data there.

I have been thinking about switching to the Rotella T6 synth (walmart carries it for only a few more bucks per gallon than the dino) on my spring change. Maybe I will reconsider if you are saying the non-synth is better!

 

I decided to try the Mobil1 synthetic moto specific oil a couple years ago. I don't recall if the engine was any noisier, but I did experience slightly harsher shifts and for the first time since I owned the bike the clutch would slip a little when upshifting at high RPM. I switched back to conventional oil and the slipping & shifting issues went away. I do have 40k+ miles on the engine/trans, and the clutch has always had conventional oil previously so that probably had something to do with it.

Rotella T is good, I use it in both my bikes and my 22re Toyota too since they all use the same weight oil. Plus it makes buying oil much more convenient I've thought about trying the T6 on the bikes, but haven't done so yet. They both carry the JASO MA rating now. The air cooled XL6 could probably benefit from a synthetic if it doesn't cause any problems. Pushing it on a hot day I've seen the oil temp up to 300 degrees.