Full transparency: Bronco sent me this cap for free for testing...and that's it. No mentions or expectations of writing a review. What I've written below are my honest feelings about the product, and if I didn't have anything nice to say I wouldn't say anything at all.
I received this cap at the end of July, 2022 and I've been running it since, putting over 25,000 miles on my truck (to give an idea of number of fill-ups). While the gas version is not for sale at this time, I hope this reinforces the quality of the product for those running diesel. If it can work with the sensitive EVAP systems on a gas truck, it will work with your diesel.
The best thing I can say about the cap: after install,
I almost immediately forgot it was on there. That's because it's so seamless to use. It feels like a factory designed product.
A quick quarter turn with the key releases the cap. The cap holder provides a great place to keep the cap while you're filling up. The key is captured in the cap when unlocked to ensure you don't lose it. Another quarter turn and the cap is locked on again.
The cap holder alone is a massive upgrade over the factory cap, ignoring the locking function. Though admittedly, if you only care about a better cap holder there are far less expensive options dedicated to that. Here's the one I installed prior to getting Tank Warden:
Its not about the rotation, it was about appr. 1/2 inch of the back of noco still pushing against inner plastic trim. Once you remove the trim, noco can go back all the way. Alternatively, you can offset the noco from the center to the left and it wont bump into anything, but i wanted the...
www.fordtremor.com
I've used the cap through a large variety of conditions. From high humidity living in the Pacific Northwest near the coast, to dry heat east of the mountains in eastern Washington and British Columbia; from temperatures as cold as -15F to as hot as 105F; on dusty, rough forest roads and long, 8+ hour continuous stretches of driving.
Throughout my two years with it, the cap has remained easy to use and trouble-free. I have
never received a check engine light as a result of Tank Warden - high praise for an aftermarket gas cap. I did receive a check engine light once as a result of pinching the o-ring, but that's user error and was easily corrected by removing and re-installing the cap. My understanding is the design was improved after my unit to make that even less likely to happen, and it only happened that one time.
I'm not qualified enough to speak on the security of the cap. Like pretty much everything, it seems plenty secure enough to keep the simple, opportunistic thieves out. If someone really wants to get in there, they'll find a way regardless of what locking cap you have. I appreciate the key/keyway isn't a common design, making it less likely a thief will know how to attack the lock itself, while still having unique bitting per truck.
To finish up, I would have happily paid the full price for the cap. I'm impressed.
Links:
A fastener was not possible for 23+ model years with our design freeze deadline we had. Going forward in the future I will see if this can be done 
Did you take part of the $5 promotion?
![What did you do to your Tremor today? [2019-2024]](https://www.fordtremor.com/data/files/featured_images/featuredimages_thumb_6.webp?1790507488)
