Looking at the car today i was thinking how i might like having a larger fuel tank only mounted outside the car. My thought was to remove the existing tank and mount it where the spare tire is removing the spare tire well and removing the back muffler and running the tail pipe out along the frame rail along side the new tank.

Any thought or ideas...

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"NEW" 1984 300D TD needs some love

Are you wanting to go on long trips. I'm having trouble figuring out what gain you would achieve other than traveling far before refueling. No lack of fuel stations here.
There are extra tanks on some benz's, but I dont see the need unless your using veggie oil. Who wants to go 1000miles without stopping.
If you really want to, I think a tank right by the original tank is best. That way you can link them together easily

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Chris
84 280sl
82 300d euro

I want to only have to fuel once a week because yes it will be home brew fuel. i have seen the OEM auxiliary tanks but if i am going to modify i would like to go more along the lines of modern cars and put the fuel tank outside the car.

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"NEW" 1984 300D TD needs some love

Probably illegal to make the modification in an area where it is likely to get damaged in a crash. Between bumper and axle is probably considered to be acceptable but in a spare wheel hanging on the back space - probably not.

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

In WW2 they sewed balloon bags on the top of cars and filled them with gas - but hey there was a war on!

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Tank Comparison | Greasecar Vegetable Fuel Systems

Or cut out the spare tire well and add a wagon fuel tank underneath the floor. I just bring 2 jerry cans with me when I go to fill up and dump them into the tank as needed. They fit perfectly the side pockets of the W124 trunk and I'm good for 1000 miles.

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CENSORED due to not family friendly words

How many miles you driving a week? It makes no sense to me to go to all the work changing your tank to avoid filling a second time but a possibility is taking a wagon tank which mounts where the spare is on a sedan and adding a lift section to increase capacity.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

the 300D has what a 19gallon tank? they do sell 12gallon tanks that fit against the stock one... I don't think if you set one in the spare space you could get more...
if you are thinking of cutting out the space where the muffler and spare sit, and installing a tank in the space left by THAT much cutting... um... wow, scary. there is a LOT of structure back there, designed to transfer energy from a rear end crash... modifying that is highly unwise.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Easier to add a second MB tank up against the original one like I did here : 1991 350 SDL Conversion to WVO

Rotate the tank 180 so the flat sides of the tanks are against each other. You can re-instal the false back of the trunk. Remove the large plastic bolt in the center of the spare tire so the tire can be slid to the rear as it is lifted out. Depending on the tank you use, you should now have over 40 gallons capacity.

Plumb them together or install a tank selector valve and switch to choose which tank to use.

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Greg
2012 S350 BlueTEC 4Matic
2007 ML 320 CDI
2007 Leisure Travel Serenity
2006 Sprinter 432k
2005 E320 CDI
1998 SLK230 (teal)
1998 SLK230 (silver)
1996 E300D 99k, 30k on WVO
Previous:
1983 240D, on WVO
1982 300D, on WVO
1983 300CD, on WVO
1986 300SDL 237k, 25k on WVO (Deerslayer)
1991 350SDL 249k, 56k on WVO - Retired to a car spa in Phoenix
1983 380 SEC w/603 diesel, 8k on WVO
1996 E300D 351k, 177k on WVO

I would be for keeping the Original Fuel Tank and adding another.

Any weight that is behind the rear Axles is going to exert more leverage towards the Rear (I guess having more weight on the rear Wheels might be a benifit in the Snow) of the Car.

When I was thinking about this I thought that a good place for anoter Fuel Tank would be to remove the Rear Seat bottom or the Rear Seat Back and make the Tank in somwhat the same shape as the Rear Seat or the Back and put a pad it. (I don't like the idea of losing Trunk Space with a larger Tank in the Trunk.)

Uncomfortable for someone sitting in the Back but someone sitting in the back is a rare occasion.
Having the Fuel Tank closer to the center of the Car spreads the load of the extra Fuel a little better.

I think it was ForcedInduction that said have an Extra Full Fuel Tank also adds more weight and that means the added weight uses up more Fuel. I guess the loss of some MPG is more significant if you are paying for real Diesel Fuel.

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84 300D, 82 Volvo 244Gl Diesel

Forum member JB3 is selling 12 and 18 gallon aux. tanks that may interest you. I purchased one a while back but haven't gotten around to installing it yet. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/341976-aux-fuel-tanks-buncha-18-couple-12-gal-%24100-dollars.html?highlight=aux+tanks

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http://myworld.ebay.com/blacklabelskates/

I wouldn't worry about safety-it's a diesel tank. You will be hard pressed to start it on fire unless you have an open flame or a very high temperature ignition source.

For increasing distance between fill-ups, you could easily tie the two tanks together with a large hose connection at the bottom and a small vent connection up top.

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$60 OM617 Blank Exhaust Flanges
$110 OM606 Blank Exhaust Flanges
No merc at the moment

I saw those awhile back. Anybody buy one and tie them together in a way you don't have to fill it from inside the trunk?

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"NEW" 1984 300D TD needs some love

Sure but the rozzers won't be too impressed with slippy diesel on the roads of where ever - besides if it gets hot enough...

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

You must drive A LOT. I fill up about once a month in the cold months and every other month or so when it's warm and I'm taking the bike most places.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.