huh, that's odd. If you Google Seafoam 500 miles
you'll find a bunch of guides on how to use the stuff. I wonder where that number came from? When it's used in the oil the usual recommendations are to add it about 500 miles before your next oil change. Yet others say to simply idle the engine for about 10 minutes and then change the oil. Those seem to be the most common Seafoam lore on the internet...
I wouldn't even call whats printed on the can instructions. It's more like recommended dosages. There is no usage info for crankcase applications beyond dosage. As for the official guide on the website, yea i've read it. Lets look at what they say about using it in the crankcase.
Gasoline Engine Applications - One pint treats 10 quarts of oil.
That's 1 oz. Seafoam per 20 ounces of oil. No other directions given.
Diesel Engine Applications - Use 1 pint of SEA FOAM to every 4 gallons of oil to clean rings and other engine parts internally. For best results, use SEA FOAM for 1 hour before oil change.
that's 1 oz. of Seafoam per 32 ounces of oil, to be added 1 hour before oil change.
The can simply says to use 1.5 oz. per 32 ounces of oil and that's it, which is close to what they say for gasoline engines on the website.
If all that isn't confusing enough check this quote out from this thread
As for changing the oil. I drive the vehicle about 500 miles PRIOR to changing the oil. HOWEVER, I called Seafoam this afternoon to discuss how long is too long to drive (was going to add that in the write up as well). They said that you should drive no more than 100 miles with seafoam prior to changing the oil.
Hmmm, perhap a call to Seafoam is in order come Monday morning... I'd like to know what they say about it myself now. lol
all i know is if your using it at every oil change and even hitting the race track with it in there, your alot braver soul then I. I'd be afraid it's to much of a good thing that's going to come back to bite me.