I do on occasion carry a Rotopax fuel container in the trunk. Not clever in a front ender but at least the Rotopax although expensive is reinforced.

 

I never bother. I find I use well less than 5% petrol miles. I try to plan to use chargers where I can. The tank will do 80 miles and there is always a petrol station not far away. I do have the 94A REX which gives 100+ miles on battery, Then I have 80 miles on petrol. So 200 mile range then an easy to find fill up of the tank.

Richard

 

Mine is the older 60Ah model so I am assuming 80+80 as a guesstimated range. I was just thinking that you probably need to do at least 60 on Rex before refuelling so I was considering RRA (Rex Range Anxiety) LOL

 

Where do you think you would be where there would not be a petrol station within 50-60miles of where you are after running for 80 miles on battery ..?
Just fill it up if you've used it for more than twenty or thirty miles.

 

No point carrying spare fuel: you have a battery in case you run out of petrol, just be sure to turn the REx on early when you know you will need it and then your "petrol can" is just that you switch back to battery when the tank runs dry. Then you run the battery flat when you expect to be able to charge before the petrol runs out again. All you have to do is be sure you never run out of both at the same time but that's easy enough to manage.

Sent from my Pixel C using Tapatalk

 

Plenty of situations where carrying spare fuel is wise. Stuck in a snow drift, road closed for up to 8 hours for a fatal. Long distances where there is no petrol station open at night, I could go on but for city dwellers I realise this is not an issue.

 

It is worth looking at some of the photos on this site of a recent i3 front end crash. I am not sure that a fuel container in the frunk is a sensible option but that’s just my opinion.

BMW i3 Crashes Into Tree - Passenger Compartment Appears Untouched

 

Has anyone ever either: added a bigger tank, or an extra close fitting frunk tank , or even a rear tank ... all with suitable pressurised fuel feed ?
Might need some software/hardware trickery but not 'rocket science' ...
160-200 miles is sometimes not enough. iirc the small tank was simply for US regulations.

 

iirc the small tank was simply for US regulations.

I seem to remember reading that the US model has the same 2.4 gallon tank but is restricted to using just 1.9 gallons.
I also thought that about whether a larger tank could be fitted but when I looked at the way it's a pressurised system it didn't seem something that was very practical - not until they become old enough to tinker with

 

My understanding the restriction on the tank capacity for the US was to keep the petrol mileage below that of the battery mileage.

Now that the petrol mileage is below that of the 94ah battery car the US now get the full use of the tank.

 

Porsches use front mounted tanks and don't seem to have safety issues.
It depends on the type of container more than where it is. A cheapo petrol can will burst or pop the top off in a bump and you will be left with a very great risk of a big bang or fire.
If you use a flexible fuel cell it won't. Plenty of race cars have them and they can be had from certain specialist sellers - some will even plumb them in - and it could then be used as an extension of the original tank.
Certainly not a cheap option but the only one I would consider.

 

Rotopax

 

Rotopax

Rotopax is a reinforced fuel container used in the motorcycle industry in the main for carrying spare fuel that can be attached with a mount plate. Apart from the lifetime leak free warranty and built in spout it is without doubt the best fuel container I have ever used. Only word of warning is it's not cheap but then again the best seldom is.

 

Rotopax are about the best off the shelf but they still aren't a burst proof alternative. The forces involved in it being squashed in the front of an i3 are going to be many times higher than a bike dropping on one.
Again I would suspect the cap would pop off first but one way or another it will still fail in a solid front end crash.
Someone like ATL will make something much more suitable though it certainly won't be a cheap fix.

 

Rotopax are about the best off the shelf but they still aren't a burst proof alternative. The forces involved in it being squashed in the front of an i3 are going to be many times higher than a bike dropping on one.
Again I would suspect the cap would pop off first but one way or another it will still fail in a solid front end crash.
Someone like ATL will make something much more suitable though it certainly won't be a cheap fix.

If an i3 owner feels the need to instal what you are suggesting then they should not purchase the vehicle as the cost of a ATL unit is way too high. Yes even the Rotopax in a serious front end crash will not I suspect survive but then again regular car fuel tanks are not bomb proof either. The Rotopax is a reasonable alternative to most for carrying a small amount of spare fuel and if it makes an owner feel better carry it in the boot instead.

 

Plenty of situations where carrying spare fuel is wise. Stuck in a snow drift, road closed for up to 8 hours for a fatal. Long distances where there is no petrol station open at night, I could go on but for city dwellers I realise this is not an issue.

Oh I agree, but my point is that the i3 already has spare fuel: the entire petrol tank is spare fuel. Or if you want to run the REx down early then 75% of the battery is spare fuel. To run out of fuel entirely, you have to run out of fuel not once on your journey but twice.

Now I admit that is easier to do then with a conventional vehicle as with the i3 you do actively aim to completely exhaust one fuel source or the other (and I have managed to get mine down to the point where it starts flashing up warnings at 15 miles total range remaining), and with any vehicle on a snowy night in Scotland you might stick a petrol can in the boot alongside the shovel and blankets, but most of time for most of the people it just isn't needed. For the others, perhaps an i3 is not an ideal choice.

 

OP should just carry the fuel in the boot in an appropriate container (not to be left long term, obviously). That way the fuel is protected in passenger safety cell, and we don't have a Darwin award fireball followed by yet more safety labels on everything. The frunk is not a good place to store fuel. We've also been in a similar situation before.

Reference A: the 1971 Ford Pinto which "tended to erupt in flame in rear-end collisions. The Pinto is at the end of one of autodom’s most notorious paper trails, the Ford Pinto memo , which ruthlessly calculates the cost of reinforcing the rear end ($121 million) versus the potential payout to victims ($50 million). Conclusion? Let ’em burn."