So i run a b18c on my semi street/track day car. I used to use Motul 6100 10w40 in the car. but i went to my sponsor shop and they had the 8100 5w-40 series and i picked it up , thought i was the same and relized after when i put it on the shelf that it was not the same oil...but hey bigger number must mean better right?

Anyway now my idle oil pressure is at 30~35 pis when i used to be 25 (normal from what i read), and i only drops back down to 25 when the car's full warmed up (like well into the 180 water temp). Also where i used to get 85 psi at WOT adn 50 at cruise at 3000 rpm i now get like 80 ish with crusing speed. I have not seem what WOT is now.

besicaly i get like 5 to 10 psi more with this higher level oil (6100 or 8100). Should i be concered at this? What is the max recomned oil pressure i should see at WOT.

Thanks

 

when i changed from 15W50 on my old 150k motor to 5W30, i saw a drop in oil pressure of about 4-5psi at WOT.

thicker oil is more difficult to move than thin, thus more pressure, and without opening up a new can of worms, less power.

 

Well i acuatly still get 82 Psi at WOT..so same oil pressure about from 3500 to 8100.

I went down fom 10w40 to 5w40 tho...and yet it reactls like thicker oil....

 

whats the difference from the 6100 8100

 

http://www.motul.com/motulbaseuk/gab_fiche1.asp

and

http://www.motul.com/motulbaseuk/gab_fiche1.asp

Basicaly the Motul 8100 is a full Synthetic and the 6100 is not so. the rest seems to be about the same.

Anyway, it internesting how the two different oil gave me such differnt reposonses to oil pressure.

EDIT: i don't think the links work http://www.motul.com/uk/produits/index.html to get the info. 8100 X-Series 5w40 vs the 6100 series 10w-40 series.

 

Id say that you just found your perfect oil, you are getting better pressure under normal driving conditions which is a good thing