My Defender came with a 150 litre tank (main & quaterpanel sub). I've had no problems with it, except that it uses the original sender, so mine used to read empty for the last 500km, I modified it, now it reads full for the first 700km, then it's pretty much linear. I've put 142 litres in it before running out, so I assume it picks up well into the last drop. I drained the tank when I did this, and there was no residue ot gunk in there. The pick ups are at the bottom of the tank, not through the sender, so they're pretty fool proof & not prone to long term problems. When I was re-jigging the sender unit I called them and they were really good on the phone with their tech advice.