I think I want to add an aux. gas tank to my 300SD...
 

Has anyone here done this? What all is involved? I have a gas tank to a '90 Volvo Wagon. It's 16 gallons, 15.8 to be exact, I think. It is still in the car, but would this fit in my trunk? Would it leave much room for anything else back there?
Would I have to cut a hole in the top of my gas tank and run a hose that just empties into it? I wouldn't be picky and want a fuel gauge on the aux. tank or anything, I just hate going and filling up.
What would you guys recommend? I would especially like some pictures of current configurations.
Thanks
David

Want,

I use 10 5.5 gallon fuel cans in the trunk and a small electric pump to refill the fuel tank from them so I don't have to pour them into the fuel tank. You will also need some type of pump to transfer the fuel.

This way, when I need trunk space, they can be removed.
I have a total capacity of 80 gallons and 2000+ miles.

P E H

We add aux taks to the trunk all the time for vegoil conversions.

A problem you may want to consider is overfilling or venting of diesel to the trunk itself. Having that raw deisel smell drafting through the car really lowers the enjoyment factor of driving a MB.

I knoe you are thinking of swapping in a lage tank...but being able to lift the tanks out for filling is a really nice feature you won;t have with a large tank. So..Make sure you have proviiosns for any overflow or vented fuel to end up somewhere other than in you trunk space.

Can I ask why you have the need to carry this much fuel?
And isn't this dangerous?

If someone smacked into your trunk things could get interesting.:eek:

It would not only exted your range but it would also kill your MPG.

Diesel weighs 7.1lbs per gallon. Thats 568lb of aux fuel. (688.7lb total) I can feel the difference in performance when a single 195lb person is riding with me, there mst be a noticable difference with the weight of 2+ extra people in the car.

Unless you live a couple hundred miles between stations, I don't see any reason to have more than 10-25 extra gallons.

I agree completely with 83-300TD.

It is a significant load to carry. That is not what my main concern is. You would need to securely anchor the fuel tank to the car as it would have quite a bit of momentum when breaking and under rapid change of directions. When my Dad got his first MB back in 1969, a 220D, we had to carry additional fuel when we would go from SF to LA on highway 5 as there where not many fuel station, and the ones we found did not always carry diesel. Now that is no longer true. Any benefit you might get from carry an additional 15 gallons of fuel would surely be out weighed by the additional load and safety concerns.

Henry

The safety issue could be solved by burning biodiesel.

Or used cooking oil....if you used 'lite' oil it might solve the excess weight problem too.

Ummm...filling a tank with biodiesel does not resolve the safety issue. Biodiesel has nearly the same ignition characteristics as petrodiesel. It is great stuff..but not magical.

And as much as I like vegoil it might not resolve the safety issue either...though it is much harder to ignite than diesel and so would greatly lower the chance of a fire following a rear end collision.

Have you considered towing a small trailer with spare fuel in it. I do this on long trips so I can haul sufficient vegoil fuel along to make it back home without resorting to buying diesel along the way. You can tow alot more weight safely than you can haul in a trunk. Still does not resolve the safety issue well though.:(

Danalinscott,

THe 5.5 gallon containers I use are top quailty. They were made to hold $5000 of liquid gold plating solution. They have an o-ring seal and do not leak vapors. I have never noticed any Diesel fuel smell using them.

I do have a small trailer I pull sometimes with another 50 gallans in it. However, even though I was given the trailer, repairs, tires, maintenance and a broken axle away from home have cost me more than I have saved using it

P E H

82-300TD,

I get 390# of auxiliary fuel (10.5 X 10 X 7.1#) and 177# (25 X 7.1#) in the fuel tank for a total of 567#.

A couple of screw in wedges on the rear springs and 225R70X14 tires keeps the read end off the ground. But I'll admit, it doesn't drive like a sports car.

I don't notice any difference in fuel mileage, Got 27 MPG on my recent trip to FL and LA which is about the average for a 300SD that others report here.

I can notice a decrease in power but the 300SD with a full load is still a lot faster than the empty 4 cylinder MB Diesels I have.

I buy Diesel fuel bulk in the late summer when its at the lowest price. When I was in Oklahoma city last fall, I bought Diesel at $1.279 and I bought enough to travel all the way home to PA without refueling again. That's why I like the extra fuel capacity.

P E H

R Leo,

How much less does the "LITE" oil weigh?

P E H

I think it might weigh a little less than muffler grease, but you can try to add a little hydrocarbon expander to lighten the molecular weight.:D

Even saving 50 cents a gallon and carrying 55 gallons of fuel would be a saving of 27.50 and considering the lost fuel milage because of the extra weight and the bother of pumping the fuel form each of those 10 cans and the wear and tear on your car the question is IS it worth it? I for one don't think so.
To each his own.

The only other person I know that did something like this was a guy with a pickup truck that had a 100 gallon tank in the bed and he burned home heating oil and got caught when his truck got in an accident and spilled fuel all over the road. Huge fine.