Flyin’ Miata recently released their aluminum coolant expansion tank for the NA, at a much more affordable price than the Moroso tank that has been around for years. The FM tank looks nearly identical to the one from Circuit Sports, but with a knurled cap and the FM logo on it.
I got this tank discounted because FM’s first batch had some fitment issues, which is why it included a 3D-printed spacer to move the charcoal canister by a few millimeters.
This upgrade is mostly for engine bling, but I also recently installed an aluminum radiator and did a full coolant system flush. Not only does this new tank match the radiator, but the original plastic tank has some grit and sludge trapped in it.
The kit comes with a few metal fittings to thread into the coolant tank, and a length of rubber tubing. I ended up using the original coolant hose because it was in fine condition, and it is nearly completely hidden after install because the new tank has its inlet on the bottom. As recommended in FM’s instructions, I used some Teflon (PTFE) tape on the fittings to make a water-tight fit.
| Part | Price |
| Flyin’ Miata Aluminum Coolant Overflow Tank for NA (discounted) | $119.00 |
