Using Sea Foam High Mileage in a Rotary engine [SOLVED]

I’ve used Sea Foam in my fuel injected 1985 Mazda RX7 a few times now, both in the gas tank and Sea Foam Spray into the throttle body. The spray has worked especially well! The first time using it really smoothed out the idle and there’s more mid-range power for sure.

Now I have a can of your new Sea Foam High Mileage. Is it just as safe as standard Sea Foam to use in my Rotary engine? Also, I never thought to pour some in the oil until I read the High Mileage label. Is the product safe to use in the crankcase of a Rotary motor?


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Jim D.
Jim D.
4 years ago

Those are great questions Steve!

Sea Foam and High Mileage are both very safe for all gasoline fuel systems and engines, including your Rotary engine.  The can instructions do a good job of keeping things on track – just pour High Mileage in your fuel and oil systems.  Two upper engine treatments per year with Sea Foam Spray will also go a long way to keep your Mazda running smoother and cleaner!

John Robinson
John Robinson
1 year ago

I Have been using Seafoam Gasoline Additive for a few years. I drive an RX8 Rotary. I add a can to the gas about every 4 to 6 fill ups.My engine has been idling a bit rough for the last 6 months or so. After bringing in to my dealer for some other work, I asked him if he could figure out what was casuing the rough idle. He told everything was according to and asked how often I used the Seafoam. When I told him he was very concerned that I might be harming the apex seals and said to stop since he was seeing white smoke from the tailpipe in addition to the rough idle.He told drive for as long as I can without the seafoam in my gas and see if I throw a check engine light. If I do he will look to see what the cause of the rough idle is. If I don’t he said lay off the seafoam. Am I using too much ? and If so how often should I add a can to my gasoline, if at all.?? The engine was replaced about 2 years ago.

Conner Kranz
1 year ago
Reply to  John Robinson

Hi John,

Thanks for the question!

First, we get a lot of questions about Sea Foam and seals. Sea Foam Motor Treatment is made with 100% petroleum cleaning and lubricating ingredients, so the composition of the product doesn’t affect seals. Here’s a video that explains things pretty well:

Second, here’s what I’d do for a fuel treatment routine:

– Add it to fuel once every 3,000 miles or so if driven regularly. It wouldn’t hurt anything to add it more often (see video), but the 3,000 mile mark is usually often enough to keep things clean
– Add a full can to a low tank of fuel (1/4 tank or so). Then, drive until almost empty before refueling. That gives the high concentration of Sea Foam time to run through the system and clean. Remember that it’s made with 100% safe petroleum ingredients, so that amount is perfectly fine.

Hope that helps and let me know if you have any other questions – happy to answer if I can!

Sea Foam