Perma Cap gas cap

Perma Cap Gas Cap

[5/13/2005] Reviewed by: Bruce Rosen - bruce.rosen@nist.gov

Applicable to: '90 - '97 '99 + 1.6 liter 1.8 liter

Replacement Gas Cap with spring loaded center hole for inserting gas nozzle.

Bought one after I lost the original cap on my 1996 Miata. At first I really liked it. Didn't have any trouble with the gas pump nozzle getting stuck as some folks had experienced, and always made sure to release the internal pressure by pushing down on the spring loaded door before trying to insert the gas pump nozzle. But now, after about 9 months I must report that the cap is on my garage shelf because it stinks. No, really, it stinks, as in it now lets gas vapor escape from the tank at a level that I can actually smell it when sitting in the car at a stop light with the top down. At first I thought I was experiencing some of the other problems that folks have reported when smelling gas in their Miata, but a little "nose investigating" soon led me to the cap being the problem. Sure enough, I put a OEM gas cap back on, and the problem was gone.

Under 5 minutes to remove


[5/1/2004] Reviewed by: Anthony Fortini - fortini@comcast.net

The PermaCap Gas Cap replaces your existing fuel gas cap. You never have to unscrew it when fueling.

I was doubtful whether this would work well, but for the $10 price it was worth trying. It's been over a year now, and I love it. You never have to touch the gas cap, or look for a place to set it while your fueling, and you won't ever accidentally leave it at the service station. My parents, wife, and kids are now using the PermaCap on all their cars. It's so easy and convenient, we all feel it should be a standard item on all vehicles.

I've read the negative reviews from others, but on my 95 Miata I have never experienced the gas splattering all over the place from the tank pressure. You can hear a small puff of air as you insert the gas nozzel through it, but I certainly don't consider that a negative. That puff of air just lets me know it is sealed tight. It's a great product and I highly recommend it.

Difficult to remove without leaving damage


[9/13/2002] Reviewed by: Thomas Di Salvio - tooxlent@aol.com

Applicable to: '90 - '97

Perma Cap Gas Cap is an interesting idea to alleviate the "inconvenience" of removing your gas cap to fill up the tank.

The three common complaints aren't that bad. 1).The first time I "used" it, I got a "blast" of air coming back at me from inside the tank. Not to pleasant, but, not the end of the world. I learned to just slightly break the "seal" by twisting the cap like a regular cap, then retighten it, and procede with fueling. 2). The Gasoline pump metal spout springs do tend to get suck on the peice that folds inside of the cap sometimes,but I just carefully pull the metal spout out and I haven't had any problems with anything breaking off. 3).I haven't had any problems with the cap maintaing the pressure that is necesary inside the fuel area. I guess this is evident by the "blast" of air that comes when I need to fuel the car. I feel the benefits of not having to remove the cap (and find a place to stash it) while you fuel are nice. In fact, If my Pathfinder ever needs a new cap, I'm going to replace it with the Perma cap.

I've read all the negative reviews (...after I all ready had puchased my perma cap two years ago). I can't complain about my cap. In fact I like mine, alot. Did I just get lucky? or did only the few people who were unhappy with this product write reveiws? Like I said, I bought my Perma Cap Gas Cap 2 years ago, and it has worked fine for all of that time. In my reveiws, I tell it like it is, in my expereince. I have used it for two years, it has never given me a problem, I like it, and, I have no problem recomending it.

Under 5 minutes to remove


Reviewed by: Ted Nguyen - phat@bayou.uh.edu

Replacement gas cap

Just like the other reviews this gas cap has a efficient goal in mind however gas pump nozzles get stuck onto the hinged door on the perma gas cap. Therefore, this product doesn't really seem to work well. I broke the cap just tring to pull the pump nozzle out. I bought it from Moss Motors and returned the product to them and couldn't get my shipping money back for it.


Reviewed by: Ron Newbold - ron_newbold@merck.com

Replacement GasCap with a center flap, no removal required to fill gastank

I have a 99 Miata, and thought this would be a nice touch on a car which needs little at this point.  Within a couple weeks of replacing the factory cap, my 'check engine' light came on. It seems  the 99s (and maybe older models?) have a gas-leak detector which turns on this light if a leak is  detected. I had to go to the dealer to have the light turned off and an analysis run. Nice idea,  but not worth the hassle on this car.


Reviewed by: Tyra E. Pierce - tpierce@lib.drury.edu

A replacement gas cap that has a small hinged door at the top of the cap which allows the driver to insert the nozzle into the cap without removing it.

I saw the Perma Cap advertized in a number of the Miata accessories catalogues such as Moss Motors and MM Marketing. I thought that it would be a nice addition to the car. So far I've fueled my car twice with the Perma Cap in place. The Perma Cap's place is now on my garage shelf and my stock cap is back on the car. I found two major problems with this product. The first is that the little spring loaded door "grabs" the spring on the gas pump nozzle, and it's difficult to remove the nozzle after fueling. The second and major problem is that the gas cap sits horizontal, and when the nozzle is inserted into the little spring door, pressure from the gas tank is released, and this, combined with any gas left in the nozzle, causes gas to spray in all directions. I'm sure that this little problem could be delt with my using my finger to press on the spring loaded door to allow the pressure to be released, but that still leaves the problem of having to shove the nozzle into the cap before any gas escapes and covers the cap and area where the cap is located. I bought the cap to SAVE time, not increase the time it takes to gas up.

I think that this product would be fine when used on a vehicle with a sloping gas cap, but I don't feel that it is well suited for use on a Miata.


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