Trapdoor for the gas cap

(Credit: AutoSport)

As much as we hate to think about gasoline--its ever-rising prices, more specifically--this is an item that could save a good bit of mess at the pump.

Gas caps can be a pain to use, especially if you're as forgetful as we are: We've left a few of them behind by accident, next to the coffee on the roof. But there's an alternative called the "InStant Fill," a device with a "trapdoor mechanism" that allows you to insert the nozzle without removing the cap. Book of Joe notes that it's also an official NASCAR product, so you can time yourself at each pit stop while reliving Talladega Nights.

[hcklbry]

Did I miss something?

So how does it prevent siphoning? I clicked on the link to the product and it didn't say anything about that either...what did I miss?

[Mike Yamamoto]

Apologies for our mistake

Hcklbry, you're absolutely right--I misread a product description found on another site. The item has been amended. Thanks for point out the error. --Mike

[WalrusSP]

Not so useful though, at least in northeast

in the description it says "Not recommended for use in areas where vapor recovery nozzles are used."

I'm in Massachusetts and the vapor recovery pumps are all over the place. Are there parts of the country that you never see the vapor recovery pumps?

[qprize]

It may void warranties - and violate laws

Many (most?) Engine Control Modules monitor the gas tank, and if you leave
your cap at the pump you'll eventually get a Check Engine Light, because the
vapor recovery of the tank isn't working. The tank is supposed to be closed so
the gas doesn't evaporate into the atmosphere, adding hydrocarbon pollution.
That's why you hear a hiss when you open the cap.