Originally Posted By: river_rat
Well, I don't know exactly when hot...but yeah, I've tried it at room temperature with a funnel and a stopwatch, and it's thicker than 5W-30 after adding it. (I tested before and after adding) Same oil brand, etc.) This was the 4 cylinder formula in Castrol GTX at a ratio of 5.5:1 by volume.
I wanted to see if I could boost ZDDP in my 5W-20 without going too thick. I decided to use a tiny bit of Lucas TB Zinc Plus break-in additive instead.
Besides, I have to mail order the 4 cylinder stuff, and I can get the Lucas stuff off the shelf.
I'm not familiar with the Lucas product you're referring to. Red Line Break in oil additive is loaded with ZDDP, and is about a 30wt oil, so it won't thicken up a 5W20. I was able to get it through AAP, on a special order. I printed the the best web price and AAP matched it, I had it in a few days. You add about 1 oz of the RL add/qt of oil and you have a nice boost of ZDDP
AD