OK--I've been nursing back to health a low mile, slightly neglected '98 Contour V6 that I bought for my son to commute to college in. Part of the idea was to run some Regane in it. Has about a 14 ish gallon gas tank. Put the whole bottle of regane HM in it and filled up. I drove it for a week pretty agressively. Not kidding when I say it runs and idles smoother, and it idles 150 rpm higher than before, at now runs at the stated rpms in the owners manual. Possibly the regane---who knows. Could have been the italian tune up. But I'm feeling like it was maybe both. Seems to have worked like advertised.