The thing about testing is you can often make a very dramatic test which appears to be completely fair and impartial, but for some non-obvious, tiny but critical important technical reason is not.
So with that in mind I'm going to do a very unscientific test here.
The WD-40 Face-Off!
So which is better the old one or the new?
(This this photo from my Galaxy smartphone was much nicer .)
This is a piece of painted sheet metal from which I wire brushed the paint, and then sanded. It's not a perfect finish but both pieces came from exactly the same metal.
I sprayed both pieces liberally. The new spray (shown on the right) is brown and very foamy. The old spray foams less and is milky white in appearance.
I stood both pieces of vertically and let any excess simply run off.
I put them on the roof of my shed and we'll see what happens.
So remember that the new formula is on the piece with two holes.
Something else to note was that the new 10-ounce can was at least $3 cheaper then the 6.8 ounce can. Right away this makes me suspect that the stuff is not as good.
Where it is now, it's exposed to full daytime sunlight and probably random bird poop and insect droppings, leaf mold...whatever.
After the stuff has had a couple days to dry (and in this current weather it will dry quickly) I'm probably going to shoot it with a spray bottle full of salt water. Maybe I'll get lucky and the cat will pee on it.
I want this to be a torture test