Castrol is bringing back R40 castor racing oil

[Japanese]

Castrol USA just announced that is bringing back its R40 castor based racing oil about April-May this year.

The oil is SAE40 and is suitable for 4-stroke racing cars, motorcycles, and 2-stroke engines too.
https://lawlessclassicoils.com.au/product/castrol-r40/

PDS
https://msdspds.castrol.com/bpglis/...5B864BD80258C59000DA35B/$File/wepp-df6bff.pdf

 

[ka9mnx]

I only remember castor based oil being used in two stroke racing motorcycles in the 60's. It really smelled good.

 

[xspeedy]

Who knew it was used to punish kids by inducing diarrhea

 

[Japanese]

Who knew it was used to punish kids by inducing diarrhea

It's still used for that and even for hair growth. It's a bean oil after all with very a high flash point.

 

[altaylar]

It's still used for that and even for hair growth. It's a bean oil after all with very a high flash point.

esters!

 

[MolaKule]

Raw castor oil cannot be used in lubrcant applications.

Any castor oil added to a lubricant has to be 'epoxidized' before blending

Now one can 'transesterify' castor oil into functional esters such as a methyl Ester, but this is more expensive than just adding epoxidized castor to other base oils.

 

[jeff78]

What's the advantage of a castor-based oil compared to conventional mineral or synthetic oils?

 

[Japanese]

What's the advantage of a castor-based oil compared to conventional mineral or synthetic oils?

It has some advantages and some disadvantages compared to conventional mineral or synthetic oils.

1. It's 100% plant base oil.
2. It has high flash point close to 500°F and decompose at temp. above 650°F.
3. It has high viscosity and stability even at high RPM and extreme temp.
4. It sticks very well to metal surfaces but also create sludge quicker than other oils. Engine internals need to be cleaned more often.
5. It's suitable for use not only with gasoline, but also with E-85, and methanol fuels.
6. It's very popular and is the main lubricant in RC engines that are air cooled, very high revving, and have very small heat dissipation.
7. It's not suitable for temperatures below 35°F.
8. It doesn't mix with conventional and synthetic oils.

esters!

It's 90% ricinoleic acid. I don't think that's an ester.

 

[JunkdrawerDog]

I used to use Maxima castor based premix in my old LawnBoy. I could mow and reminisce about my dirt biking days simultaneously.

 

[vintageant]

We are almost in June and no indication this is available yet. Any update?

 

[robbobster]

I only remember castor based oil being used in two stroke racing motorcycles in the 60's. It really smelled good.

 

[Japanese]

We are almost in June and no indication this is available yet. Any update?

I just emailed both BP and Classic Oils USA and will let you know soon. You can email them too (if you like) at:
[email protected]

[email protected]

Here is the current product page but it says sold out on it:
https://www.classicoilsusa.com/products/castrol-r

 

[vssjim]

When the HD XR flat track engines were new I think they ran Castrol R40 or R30

 

[Japanese]

We are almost in June and no indication this is available yet. Any update?

When the HD XR flat track engines were new I think they ran Castrol R40 or R30

Castrol R40 is not sold/distributed by Castrol USA or BP but by Castrol Classic Oils USA. It's a product formulated/blended by Castrol Classic Oils UK.
The oil is suppose to be available this fall 2026. Read the second email screenshot below.

This the email by Castrol/BP North America:

This is the email by Castrol Classic Oils USA:

Phone:
1‑409‑433‑8111

Email:
[email protected]

Website:
https://www.classicoilsusa.com

Address:
Formula Distribution & Logistics LLC
3177 Summit Drive
Port Neches, TX 77651
United States