Blending different straight weight oil

[quick_16]

Would like to know how to blend two straight weight race oils and if there is any issue with that. Same brand, oil almost the same additive package. One is 30W one is 40W
My eng holds 9Qts and I'd like to start with 6x 40W and 3x 30W

 

[Paul2007]

What benefit are you looking for that either oil won't provide?

 

[ARCOgraphite]

Trying something a bit lighter than SAE40 for more power? Sounds like a good start to me. Should be no issue if you have good pressure and you dont have a history chewin on bearings. Castrol, Lucas or JGR?

 

[Steve S]

All oils are compatible look at the ingredients.

 

[quick_16]

Here's what it looks like if I mix them equal parts

________p_______zn______ca______mo
new 40W_1757____1802____1653___200
old 30W_720_____778_____1945___263
blend___1239____1290____1799___232