Adding to gas tank

I know there is a larger gas tank made to replace the OEM, however, I was wondering if anyone had added a second tank under the bed where the spare tire would usually sit. I don’t carry a spare and there is plenty of space under the bed.

 

No and it would make more sense to upgrade the current tank.

 

https://www.tundras.com/threads/adding-a-2nd-gas-tank.97778/


but from a brief google search I don’t think someone makes an auxiliary gas tank for the spare tire carrier, you could put a second tank in the bed

 

Tundras and rear end collisions don't jive real well

 

Like @Tundra234 said, the larger 38 gallon factory tank is a better option. Transfer flow also makes a ~46 gallon tank. I looked at both for my ‘13 but opted for a factory 38 gallon: it’s much lighter, reuses the factory 26 gallon mounting locations, and was about half the price. You do need to figure out the front gas tank mount/crossmember but it shouldn’t be too difficult. I have all the parts in my shop waiting to do the conversion on my truck.

Some do the online dealership parts places have an occasional 25% off plus free shipping promo which helps drop the price. Unfortunately, they won’t ship the new fuel tank for free - or what I’d consider a reasonable price - so you will need to find one locally. I had to get one from a dealership 3 hours away (I had family headed that way anyways). I called ahead of ordering as asked if they would hold on to it for a week or two before they could pick it up and they were ok with that. I was able to order it with a discount, then pick it up. Note, however, that most dealerships that sell online won’t match the online price if you walk up to the same dealership’s parts counter.

Several years ago, legislation was passed that makes replacing the fuel tank in a gasoline powered vehicle with an aftermarket part incredibly difficult. I had a pretty in depth conversation with the guys at Titan Fuel Tanks (they are just down the road from me) about a larger fuel cell for our trucks. The gist of it was: legislation prevents them from doing it without millions of dollars in certifications for EACH product they develop or vehicle they develop it for. The crux of the issue is the lining required for gasoline powered vehicles and the bras tax/testing surrounding that liner. Diesel-powered vehicles aren’t subject to the same legislation so they continue to manufacture replacement tanks for those vehicles. They can use a different liner but despite it being suitable for gasoline as well, they can’t sell it for gasoline.

As I understand it, Transfer Flow already had already developed the tank and had been selling it before the new legislation, so after a legal fight, they were able to reintroduce it.

The only way you could add a second tank to the vehicle would be as a transfer tank that pumps in to the fuel filler. But even that would be tricky and may throw codes. Not quite as easy as it used to be with dual tanks in a pickup.

That’s why I went with a larger factory tank.

 

Thanks blenton, prob the most informative response I have ever read in a blog. I’ll definitely take your recommendations.

 

65 gallons. Anything is possible depends how much you wanna spend.

 

Just so you know, the 38 gallon factory tank only holds about 32 gallons (do a search - there are a TON of posts about it). I am still glad I have it, until it is freezing out and it takes a while to fill

I do get about 500 miles on a tank.

 

It holds 38 gallons, there is just a 6 gallon reserve when the gas light turns on. The 26 gallon tank is the same - gas light turns on at 20 gallons. There is some speculation as to why Toyota does this, but since the tank is basically flat-bottomed, 6 gallons isn’t very deep in the tank - maybe 3” deep. Supercharged trucks are warned not to floor it with less than 1/4 tank because the acceleration can cause the enough movement in the fuel cell to run the pump dry for a second.

So, yes, you can put 38 gallons in it. I’ve put 26 gallons in my 26 gallon tank. It’s not a good idea, though…

 

So in theory, I have 6 gallons left when the truck says zero miles to empty? (talking theory, not what is best for keeping the fuel pump cool)

 

Correct. Give it a go and see what happens

 

Yup Blenton is dead on, I think most I’ve ever put into my 26 gal is about 22 gal, I’ve driven on E for about 40 miles but no more

 

Titan fuel tanks makes a spare tire tank. They can only market them for diesel, as explained above, but you should be fine to use it for gas. You'll need to figure out getting it to pump into your factory tank without throwing codes.

 

if I do the tank, this is the route I would take also.

 

As a 2021 Tundra owner I can confirm this is absolutely false information. I have put 36.2 gallons into my 2021 on a road trip once. I went 644 miles on that tank.

 

Dang almost 18 mpg that’s crazy!

I don’t think I have the courage to drive it that low on E though

 

It isn't a great idea to routinely drive past empty as the fuel pump could get damaged but in an emergency its no big deal.

 

100% agreed! I remember that trip very vividly. I was coming from Texas going to Phoenix Arizona, and if you have ever driven along I-10 from New Mexico to Arizona there is absolutely nothing. We were thanking the good Lord we made it to the gas station that we did. I have never let it get that low since.

 

Im driving to Phoenix from SoCal in a couple weeks to get a camper and I have the smaller gas tank. 100% bringing some jerry cans along.

 

Love it!!

 

Yep about 6 gal in reserve to keep the pump submerged

 

You can easily add a gas tank where the spare tire goes. The old school way is to get one at a pick and pull that fits, or you can buy an nice aluminum one from Summit racing.

 

I have a transfer flow and regularly hit about 550 miles before I fill with approximately 33 gallons. I wish I had just gone with a 38 gallon tank instead of the transfer flow due to the weight difference, but I do like it. At the time, it was cheaper for me to get the transfer flow so I went with that.