extra fuel tank

I'll be making one at the end of the year once I get my Prius. I do a lot of driving from the UK to Scandinavia and am going to be taking it on a European road trip.

The tank will be detachable should you not want excess weight when not using it so when I've made my one, I'll take pics of it and make them for people if anyone is interested.

Reason I'm waiting just now is to find out the exact dimensions of the space underneath the main cargo area so I can mold the tank to the shape. I've made detachable auxiliary fuel tanks before for a Ford Escort van I used to own and never had any problems with it. Just hooked in and hooked up quite nicely.

 

I agree that something safe that could be shut off for normal use would be handy for trips OR if we ever have another embargo like I lived through in the 70's. I'd like the idea of going 700 to 1000 miles between fill ups. That's one reason I would consider the Fusion Hybrid. My TCH was good for 600 miles easy.

 

I would be interested in this.

 

There is two ways to do it, and as someone who's primary concern is safety I like to go for the safer option.

First option is to go for a tank that just drains into the other one, but this is annoying to install and non detachable. Not recommended.

The other is having a tank that pumps fuel into the main tank by flipping a fuel transfer switch that transfers fuel from one tank to another. This is the system that I used on my old van.

The materials I used to make it were a strong aluminum tank welded together that attaches to mounts on the body of the car. Ideal safety location for this is as close to the rear axle as possible because in the event of a collision it won't be damaged too badly. Encased within the aluminum box will be a plastic tank that is built to aircraft fuel tank standards for light aircraft, this part is the most expensive, but not overly so as I believe the safety benefits of these things are worth it. They're so safe in fact that you can drive a Jeep over it and it will not break or rupture.

Since I do not have a 2010 Prius just yet I don't know how it is going to all fit together or what connections I'll need for the fuel pump, so I can't design the tank yet. However, once I get the car it is one of the first mods I'm going to be making, so if there is great enough demand for this then I can design it as an easy to install kit along with video installation instructions.

What tank capacities will be people be looking at so I can get a general idea?

 

I would think something 5 to 7 gallons would not be too big, would keep the weight down but still provide a big leap in tank range.

I would have been more than willing to not have the storage area under the cargo mat and had more tank capacity.

 

25 litres (5.5 gallons) would seem like a decent tank size. That could easily push you over the 1000 mile mark if you're just doing "normal" driving. Would put tank capacity up to 70 litres and the weight of fuel in the car (total) would be 51.6 Kg (or 113.8 pounds)

Not too heavy at all

 

I'm concerned about the safety aspect of this kind of setup, specifically with the possibility of a fuel leak onto the roadway. Any kind of detachable tank seems prone to leaking at the point of coupling, whether or not the auxiliary tank is installed. What type of connection/fitting have you used or plan to use to ensure success?

You wouldn't want a slow leak to drip onto the roadway as you are stopped over a burning cigarette butt.

 

Since I don't have a 2010 Prius right now I can't say the exact specifics of what will be involved because I don't know.

The last time I installed an Aux tank everything was designed and build to light sport aircraft standards, of which are extremely high! The main tank itself is of the same material used in light aircraft fuel tanks, which are fairly indestructible, which was even then encased within an aluminum container. As far as leaks go, provided it is installed properly then you won't have any! The exact same fuel lines and clamps are used for aux tanks as main tanks. This stuff really is idiot proof provided you know how to read instructions or follow video tutorials. As far as the fittings on the tanks themselves go, they were fitted in securely on both sides of the tank and sealed with epoxy resin.

Once I have the Prius, and designs done, I'll put them up in this section of the forum so people can comment on them, offer suggestions or even modify them!

The last time I did this setup, the setup passed inspection at its MOT.