I agree.
I wish I had better results to report, but not so.
I was running up to 230* in Houston's stop 'n' go traffic, using my SPAL puller fan, with 50/50 glycol/water mix
I purchased the Water Wetter at an auto supply store and read the instructions. It was recommended that the best results would be achieved with less than 50/50 mix (recommended was 15% glycol/85% water), so I drained the radiator and replaced it with a glycol/water mixture in the 15/85% range (I figured that with the mixture still in the engine I would end up around 20/80, since it was still 50/50).
No improvement...still running at 230* during the afternoon on the hot Houston freeways in stop 'n' go traffic WITH the SPAL fan on, once at highway speeds it runs between 195* and 210* with the puller fan OFF...no better than with 50/50 glycol/water.
My fan is shrouded on the top only, the next job will be to make side shrouds. That will happen when it is put up for the winter.
BTW, my radiator is a HUGE aluminum Griffin unit, reported to be able to cool up to 600 horsepower, and my engine is a box-stock 5.0HO out of a 1989 Mustang GT, just converted to carb (includes Edelbrock Performer manifold...not the Performer RPM, Edelbrock Thunder carb, and standard 4 into 1 headers/sidepipes), NOT a high performance unit with a lot of go-fast goodies.
Cheers!
Dugly