Anyone Retrofitted A Larger Gas Tank?

[bmwman91]

So, has anyone fitted a larger capacity gas tank to their 318iS? It sounds like the 325i tank is ~3 gallons larger. Did any models come with an even larger one? More importantly, can it be swapped in without modifying things? I would assume that everything fits without any issues since they all have the same chassis and rear suspension/subframe. I could definitely appreciate larger capacity for road trips!

[roguetoaster]

I'm going to bump this for an answer, would be perfect for ChumpCar teams. Anyone?

[e30jake]

Somewhere in the rare parts thread I remember seeing an OEM expansion tank that fits on the back of the rear seat. Thats as good as I got

[george graves]

Alpina made one. Google Alpina auxiliary gas tank

[bmwman91]

Hmm, never seen that before!

I think I'd prefer to keep the fuel under the car, though. Maybe nobody has tried it, which means that there is only one way to find out. Maybe this coming year I will look into it once the weather dries out.

[decay]

So, has anyone fitted a larger capacity gas tank to their 318iS? It sounds like the 325i tank is ~3 gallons larger. Did any models come with an even larger one? More importantly, can it be swapped in without modifying things? I would assume that everything fits without any issues since they all have the same chassis and rear suspension/subframe. I could definitely appreciate larger capacity for road trips!

my car had just been sitting for a year and a half so i ran down the tank as much as possible before refilling with an E85 "refresher" tank. fuel light on, one hiccup about a half-mile from the station.

14.7 gallons, 1991 318ic.

i actually want the opposite of you- i've done a lot of weight reduction on this car. if you weigh with a full tank... change the definition of "full tank". :)

so what's the smallest e30 tank? and if that's what you have, wanna make a swap day of it, since we're both in the bay area?

[bmwman91]

Hmmm...tempting. I would be more concerned about the cabrio tank not fitting the coupe body than a 325i coupe tank not fitting though. Weren't the rear crossmembers and driveshafts different between the coupe and cabrio?

[M-technik-3]

Chump drivers might want to consider the E30 extended range tank. Added 20 liters.

[bmwman91]

Holy shit. Where does the driveshaft pass by it?

[M-technik-3]

Holy shit. Where does the driveshaft pass by it?

It doesn't! It mounts on the on the trunk forward bulkhead.

[roguetoaster]

Chump drivers might want to consider the E30 extended range tank. Added 20 liters.

Awesome! Now if the 12 people who actually have one would kindly sell them for reasonable money Chump teams would be in heaven. Especially those M20 guys, when they aren't eating rocker arms and waiting in the paddock for repair of course.

Really this question should be reposted in M20 tech if it is not already to get real 325 tank capacity.

[Dj Buttchug]

I mean i just did it. I didnt switch tanks tho I switched chassis. lol

[decay]

Hmmm...tempting. I would be more concerned about the cabrio tank not fitting the coupe body than a 325i coupe tank not fitting though. Weren't the rear crossmembers and driveshafts different between the coupe and cabrio?

not that i'm aware of (but that doesn't mean no).

checked on realoem, same 63L tank for '91 318ic and '91 325i coupe. '91 318is listed a 55L tank.

small tank:


big tank:


so that's just over 2 gallon difference... i would think to be worth it on your end you'd want the big tank and an auxiliary. but if ~50mi does it for ya-

[bmwman91]

I can't put the aux tank in because of my sound system haha!

It does sound like a mostly-straight swap. I will look at some wiring diagrams and see what needs to be spliced to accommodate the dual level senders.

How long does it usually take to drain and pull the tank?

[Dj Buttchug]

I wouldnt imagine too long. heres an issue I have run into. For some reason my fuel gauge does not work. I used my cluster from my 318i because i sold the one in the 325i. For some reason the dual level senders dont work with the 318i cluster???