First oil analysis done by Blackstone labs, seems to be good.

[Jake Raby]

Your first sample on DT40 will be compromised from cross pollination, unless you used the BR flush oil as we prescribe.

[steved0x]

Originally Posted by Jake Raby

Your first sample on DT40 will be compromised from cross pollination, unless you used the BR flush oil as we prescribe.

I have seen that described here and other places. I called and emailed Joe Gibbs racing to see if they recommended the BR30 or BR40 and they never got back with me (I should have just contacted you guys), so I just went ahead and did a regular oil change. I guess when I do the next change in 6 months that will eliminate the cross pollination? Will having the traces of Castrol 5W40 in there degrade the performance or shorten the life of this fill significantly?

Thank you,

Steve

[Coaster]

Thanks for sharing. Here is my first one. Sticker on windshield from PO said the previous oil was Mobil 1 5/40W. I too changed to DT40 (also didn't use BR oil flush) and also didn't pay for TBN (I'm wondering if I should now?).