I live in Ottawa, Ontario, Canada (for better or for worst).
I've never used any such products. Never! I never believed in them.
Like I wrote in another post, I followed the advice of James Sweet
who suggested to use Techron. Excuse my ignorance, but I don't know
what Techron is exactly. A brand name or the a product itself.
In any case, I understood what James suggested and went to CT to have
a look at the products being sold.
I do NOT particularly like the Canadian Tire's brand, Motormaster. I
feel that more often than not, you'll end up with an inferior product.
In particular when it comes to rechargeable batteries for tools. So I
basically never, ever buy a Motormaster product.
I figured that since it is impossible for me to know if brand X of
cleaner is better than brand Y, then I might as well take the least
expensive one. And fortunately for me, the $14 bottle was on sale for
$9. That's how I ended up buying the Motormaster brand.
Actually, I also bough the fuel injectors cleaner, also by
Motormaster. It was also on sale.
Like I said in another post, I first tried the fuel injectors cleaner
and the improvement was negligeable.
Also, I suspect that the suggestion made by another poster, Clay, as
to use the car in situations were the engine will warm up and cool
often is preferable to long highway drive. As Clay pointed out and I
suspect that he might be right, that situations where the crud heats
up and then cools down is preferable in order to get rid of it. IOW,
it is the action of the liquid in combination with the process of
heating and cooling that eventually breaks it up.
As for me, my only regret is that I cannot have my car tested again to
see if further treatment will have further impact on the emissions
test. Guess I'll find out in two years :-(
I do not intend to use such a product on a regular basis. I used it
once. I'm doing a second treatment right now and I'll do a third
treatment prior to my oil change. That's it, that's all.