Has anyone tried the Red Line fuel additive and how does it compare to other brands

No, but I just started using Stanadyne http://www.stanadyne.com/new/ppt/index.asp
and that stuff ROCKS! My rig seams to now be cured of it's smoking habbit :-)
Burt

I used it for 9 tanks, am now running Standyne. My experience is that Standyne reduces engine noise (fuel knock?) more than Redline. MPG gains with both Standyne and Redline are negligible maybe .5MPG’s hand calculated but a MPG improvement that small can be attributed to other factors.

I personally don’t run additives for the MPG gain, but more for the fuel quality (i.e. cetane) and lubricity improvement, and IMHO as Standyne is a diesel pump manufacturer I think they know a thing or two more about diesel lubricity than most other companies. Redline is certainly much easier to find than Standyne as it’s available at most auto parts stores, and I think it’s better than running just straight #2 diesel, but for my $40k investment as it is recommended by GM and more importantly quite a few of the knowledgeable members of this forum Standyne gets my nod.

My .02

Stanadyne is the best out there. Not only do they manufacture injection pumps, but they do injectors as well. They pretty much manufacture fuel systems as a whole. The best part is that they are recommended by GM.