I had a fuel smell on my 2005 and soon after the smell I got an engine fault for a leaking injector. If memory serves I smelt it when it was not running as well. I replaced the injector in question and pulled all the injectors and replaced the o-rings for all of them. Also cleaned all of them It sounded pretty daunting at first but it was not too bad after all.
I assume you have no CEL Check Engine Light on, and mine didn't either for a while while the smell was going on. But from your gas mileage you couldn't tell, mine was only getting 13 mpg at the time. Be aware the dash MPG is done from cumulative totals so I wouldn't count on that reading to tell me an injector is open.Got her up to 15 mpg shortly after changing out the open injector. Do you have a diagnostic tool? Something that can read your injectors. If its an open injector you should get an engine rich code on either bank 1 or bank 2. I would check the rich/lean situation somehow, pretty sure you'll need a code to show up to do that unless you have a more sophisticated tool than I did at the time. I had an Amazon Bluetooth ODB-II reader and an app I think InCarDoc and it actually told me there was a misfire on #5 cylinder, By that time the vehicle was running like $%() so I knew I had an issue.
I bought an injector puller off of #bay for about $15, however I did the job before it got there, so IMO a puller is not needed, if this turns out your issue.
Sorry I couldn't be more good news. If a code does show, go to Advance and get them to read, but this will be a generic code, not a LR specific code. I think mine was a PO0301.
Sorry for all the words, but I suspect an injector if you can't find a leak. But that;s just based on my limited experience. Good Luck if you find a code maybe I could be more help.