[Rionalma]

I've got a Honda CRF250R. This has a split case with separate oil for the engine and transmission.

I'm looking for a good oil/oils to run in both sides. I've been using Rotella T6 5-40 thus far for both, it seems to work fine. I change engine oil every 20 hours or so, transmission oil when it starts to feel grabby, which is usually around 10 hours.

I've tried ATF type F in the clutch side, it felt too grabby. I'd prefer something cheap for the clutch side as I change it often

On the engine side, it needs to be 5w or lower, otherwise kick-starting in the cold (10-20f) is a huge pain.

Kind of lost and spinning my head around with all the different options.

I just realized that I forgot to mention - I'm looking to change oils because Rotella t6 is a bit on the expensive side.

[JimDirt]

Welcome to the site !!

Unfortunately , in these engines , that Rotella is about the cheapest you are going to find (I think) that has the correct things to work for a wet clutch .... That is what you have to be concerned about , is that it meets the JASO and MA requirements to not fry your clutches ........ the Amsoil I currently buy is about $14 a quart , I change oil about every 4-8 rides depending on conditions .... basically when I see the oil (engine side) discolor , then its time to change it , regardless of how many hours are ran , as oils like Maxima and Amsoil (both are what I use after switching from Rotella (blue bottle full synthetic) are specific to bikes and wet clutches .... That Rotella is pretty good and I ran it for a long time ....

My only issue was smooth shifting (I rarely use the clutch when shifting , so I need smooth engagement) , the Maxima followed by the Amsoil (in reference to which is better shifting) , is what I use now , since changing from the Rotella , and I only switched from the Rotella because of the need for smoother shifting , as I missed shifts occasionally with the Rotella , , currently I use Amsoil Dirt 10-40 , I ride in 20 degree F. up to 110 degree F. , with no issues in both my bikes , I have not had a issue shifting since .... , Regardless of what I buy it is ALWAYS Full Synthetic .... you do not need to change it as frequently (if you are not in dusty conditions) , you can run it for 20 or more hours without issues) compared to a few hours with Petroleum oils , I know this for a fact because I have done it . my 02 450R currently has over 400 hours on the current piston , rings , clutch , without any issues whatsoever ... it has , during those hours , been filled with Rotella T-6 Full Synthetic (blue bottle) then Maxima 10-40 full synthetic , and now Amsoil Dirt 10-40 , if that says anything ..... I would stay away from regular "car/automotive" oils , with the exception of the Rotella ...