If all else fails maddat sell larger aluminium box fuel tanks for the 510's. 60L for $1600 AUS with all the bells and whistles. You could probably make it fit.

Interesting, all the B310 Sunnys I've owned had large fuel tanks. Were sunnies in your country fitted with smaller tanks? Or maybe the fuel gauge is reading empty when it actually has 10 liters left ... or perhaps the tank is dented

Japan B310
* 50 liter: Sedan, Coupe & Wagon
* 47 liter: Van

I want to Travel David Lot of Gaps from Petrol Station to petrol station Only 30liters Is Only about 300ks In the Mild A14

My B310 tanks were very fine, I never felt the need to upgrade

What kind of problem are you trying to solve? The gauge needle moving erratically is usually caused by a bad sender, a new cap won't help that problem

A new cap/better cap can help with fuel leaks and can help with fume control

I Have a Sunny B310 Iam sick Of the Fuel Gauge All ways Going up and Down All so Bought a Cap from Super Cheap and its No longer closing firm... What up Grades Have People Done To Their Sunny Sedans I would Like a Bigger tank and better Cap to ??