Extra fuel capacity for a Hilux
 

I've got a 2015 Hilux Doublecab that I am planning a trip in and one mod I need to do is to increase the fuel capacity. A long range tank is perhaps one option (just been told one make won't fit due to the diff lock on the rear), there may be others though I also don't want it to reduce ground clearance by too much.
An extra tank seems a good option but Front Runner have just confirmed that they can't sell them in Europe (I am in Scotland) and I can't find any other makes.
Carry jerry cans in the back - not ideal as they would be heavy to lift in and out, especially as they would be against the bulkhead; also some ferry companies don't like them, even when empty.
An inboard tank up against the bulkhead - possible, if safe, odour free and there is an easy way to fill/empty it. I was wondering if a marine diesel tank would work, I assume they are liquid and vapour tight.

Ideas?

maybe look into this: https://www.arb.com.au/toyota-hilux-...tanks-storage/

What do you need extra fuel range for? Where are you going?

Extra tanks are one of those things people think they will need before a trip, but usually don't. If you have 500 km fuel range there are very few places you will need extra fuel capacity.

years ago I put a DAF lorry tank in the bed of my Hilux. It took up a lot of space and was of no use except for smuggling cheap fuel from one country to another where it was far more expensive (e.g. Iran to Pakistan).

Take a couple of jerry cans and you'll be fine, though you probably won't even need these. The only time I can recently remember needing extra fuel range was an 800 km stretch of ice road in eastern Russia, and that was in a petrol Hilux Surf, off road, constant 4WD in -30º C. In my diesel Hilux I can do 800 km on one tank.

EO

I want the extra capacity so that I can fill up with good fuel and be able to avoid more "rural" fuel stations. One of the reasons is with a Euro 5 diesel I would prefer to use better, low sulphur fuel when I can find it and avoid any issues. Planned trip is to Mongolia (exact route flexible)
I've used a long range tank before on two trans Africa trips for similar reasons and quite liked having the option and flexibility. For the same reason I put an Acerbis tank on my XT600 so I can have a big range without bothering about having to find fuel.

I see your thinking, I would buy fuel from quality outlets in Russia (Lukoil / Gazprom / Rosneft) which are spaced closely enough not to need an extra tank.

For Mongolia, all fuel is imported from Russia (or China in the far south I think), so you're buying the same stuff wherever you go.

In 2016 in Mongolia all diesel I purchased was 3000ppm sulfur. Not sure whether I saw any ULSD bowsers. As mentioned they exist throughout Russia at major brand stations.