I fitted one of these tanks a year ago. It's been one of the best modifications I've done. In most conditions I'll generally get to 900km-1000km before I'm ready to put fuel in. When filled the gauge stays above full for the first 350km to 400km then slowly starts moving. The fuel gauge has acceptable accuracy for the last third
One of the advantages of the poly tank is it doesn't add much weight being only several kilograms more than the original 80 litre version whereas the long range steel tanks are significantly heavier.
The tanks are different between Thai and Spain so make sure you order the correct ARB part. TAD115 (Spain) or TAD116 (Thai)
I DIY'ed the installation which took about 6 hours ... so it was the best part of a day. It's not technically difficult but the rear most strap is a very tight fit around the tank that took some encouragement to get the bolt hole to line up. I used a piece of chain with a hook on the end and levered against the frame rail to pull the strap in towards the tank while an assistant got the bolt started. I used anti seize on the bolts to keep the threads protected in case I ever have to drop the tank in the future.
The instructions are based on the ute back twin cab as that would be the majority of their sales. They document a modification to the fuel filler pipe which is not suitable for a tray back. Therefore I had some fiddling around and redesign of the modification to get that right.
