I'm using the older formula (called ESP Formula 5w30) in my Corvette and I like it. On my last UOA with it, the viscosity finished up right where it started. The same can't be said for the 0w40 version of this oil, I've seen a few UOAs with this oil on new Corvettes and it ends up thinning out to the point where it's lower than the 5w30 version. I've still got 4 oil changes worth of ESP Formula 5w30 and once that runs out I'll start running the new formula. I have always liked the amount of manufacturers approvals that this oil has.