I tried to add a bottle of gas line antifreeze a couple of years ago. The long neck bottle did not open up the fuel cap. I had to get the funnel out and use it.

 

I have a long funnel that might have the same diameter as the factory funnel. Might not work, but will give it a try tomorrow, and see if it works. If it does, I'd use it from now on when adding fuel stabilizer, since the stocker is too damn short, so made a small mess. It's an old funnel, so even if it works, have no idea where the hell I bought it. Ha ha. It's an orange one, with a very long neck.

 

Nice that you found a funnel but you really don't need stabilizer.

 

I haven't tried it but an old-skool transmission funnel may work.
Now...I haven't needed to fill a trans in ages so WHERE is that funnel! Hmmm

 

Are people really struggling that much with the factory funnel? Never had any issue even with the stupid carb approved cans.

 

I believe the preferred method is to be used rectally.

 

Hey, everyone has their thing. Who am I to judge?

 

Trying to add 5-10 gallons of fuel thru the oem funnel is tedious. Many times a year I do that because our local grocery store teamed up with a gas station and we earn fuel reward points which have to be used within a month. The most fuel you can apply points to is 20 gallons. If my truck only takes 12 gallons to fill, I forfeit the points on 8 gallons, which at times can be worth $2-3 per gallon. If fuel is $1.50/gal and I use 20 gallons, I still have $.50/gal which remains on my card if I have $2/gal on my reward card. In that example, they do have a minimum charge/gal. I have filled up with 20 gallons of fuel for a few dollars.