Does diesel fuel go bad

KATOOM wrote:
t I'm fighting weight ratings as it is and I cant afford to add more weight in the bed

Yes, 50 gallons does add some significant weight. It's not always possible, but I try to climb/descend grades with as little fuel on board as is prudent.

I agree. I'd really like the advantages of a larger fuel tank or an aux tank in the bed but I'm fighting weight ratings as it is and I cant afford to add more weight in the bed for sake of fueling convenience. Transfer Flow makes a nice product too.

OP lives near me and there is not much of a chance of him getting biodiesel if he buys locally.

I think if you use some biocide and possibly a demulsifier you should be good to go. Depending on what kind of range you are looking for it might be better to replace your tank with a Transfer Flow as Cummins12v98 stated. I have a Titan tank in mine but if I had it to do again I would get the Transfer flow.

I've never been a fan of biodiesel. The stuff is too corrosive which can eat up older trucks rubber lines and seals not compatible, and it gels easier than normal #2 in colder weather. Unfortunately there are stations which only offer bio blend diesel, but I understand that the ratio of bio is minimal. Knowing that algae is probably the biggest issue with older diesel, using some fungicidal protectant and full tanks should be all one needs. And if you dont plan on starting or moving a vehicle for over 6 months then there are far more things to be concerned with besides fuel.

Bob Vaughn wrote:
I just bought a diesel truck and am contemplating installing an auxiliary in bed fuel tank. I am wondering if there is a shelf life of the fuel that is in the tank ? Does it go bad or do I have to use it within a certain time. My truck is garage kept.....

Forget the in bed tank they just take up room. Get a TransferFlow replacement tank they come in around 50 gallons or so. That way your fuel is always fresh.

The modern diesel engines are fussier and the modern fuel is poorer. Diesel does have a shelf life. 6 months is the maximum I have seen recommended for fuel with a higher biodiesel content. We store 6000 gallons for 6 months at a time without ever seeing any ill effects.

Gasoline will usually go bad before diesel, add some fungicide to diesel to prevent growth in stored fuel. :)

Normal case scenario is that diesel lasts for a long time. Much longer than gasoline. Rule of thumb is that if you live where humidity is high or during cold winter months, make sure to keep the fuel tanks as full as possible while inactive so as to keep any condensation moisture from getting in the fuel. That rule goes for storage of any vehicle too because fuel tanks stored at low fuel levels leave room for condensation. ALWAYS store your vehicle, mower, boat, etc. with the fuel tanks full.

See: Diesel Doctor FAQ

I generally have 40 gallons that sits for about 6 months at a time, and have had no fuel problems. I usually put in some stabilizing stuff before it gets stored for that length of time, but that's just me.