How to store diesel for six months...additives?

Hello, I am proud new owner of a 1998 TDI 5spd stick super beetle. Appears to be in very good condition. In the far past I had heard good parts of diesel were slowly being removed. That one shoud add a cup of transmission fluid to each tank of fuel. That was way back in the 90's. Now I intend to leave this car sitting for six months while I am away. Should I leave it with an empty tank? or a full tank to reduce condensation....and should I add a cup of transmission fluid to it....and THEN should I had some kind of additive...like stabil...? Appreciate any input.
rookie jim

oh......think fuel economy 51mpg. Not all that great I don't think. And perhaps a tad less as didn't top it off like I did on the prevous tank.....so maybe 47 and up. Should/could be better methinks....

For six months I'd just fill it up. ATF is a pretty lousy fuel additive. Two stroke oil is far better.

6 months 2 years, it doesn't really matter. Diesel does not have all those evaporating VOCs and ethanol in it like gas does. Stabil is for gasoline. Don't use it. Kinda like motor oil. Diesel can be stored for a very long time.

the only additive you need to add is Power Service or Standodyne. But then they don't help with storage, just lubricity and cetane rating.

Gemrod said:

Should I leave it with an empty tank? or a full tank to reduce condensation....and should I add a cup of transmission fluid to it....and THEN should I had some kind of additive...like stabil...? Appreciate any input.
rookie jim

oh......think fuel economy 51mpg. Not all that great I don't think. And perhaps a tad less as didn't top it off like I did on the prevous tank.....so maybe 47 and up. Should/could be better methinks....

Click to expand...

Congrats, we have had our 99 NB for many years of service. Many opinions on fuel, additives, storage, etc.. With many miles and long storage periods in between I've liked BP diesel, used many additives and like Amsoil or Howe's the best. The Cenex RoadMaster XL diesel has been interesting too.

Diesel fuel is very dissimilar to gasoline in many perspectives, but it comes down to finding a fuel station which has high traffic and the fresher fuels, newer in ground tanks and pumps, and for just 6 months you are probably good to go.

If the NB is new to you, with service records of any sort? Look to preventative maintenance of a new or rebuilt fuel pump, fuel filter, a new timing bel....,

Look to the trusted mechanics area of this site for someone near you. Have fun.

Gemrod said:

Hello, I am proud new owner of a 1998 TDI 5spd stick super beetle. Appears to be in very good condition. In the far past I had heard good parts of diesel were slowly being removed. That one shoud add a cup of transmission fluid to each tank of fuel. That was way back in the 90's. Now I intend to leave this car sitting for six months while I am away. Should I leave it with an empty tank? or a full tank to reduce condensation....and should I add a cup of transmission fluid to it....and THEN should I had some kind of additive...like stabil...? Appreciate any input.
rookie jim

oh......think fuel economy 51mpg. Not all that great I don't think. And perhaps a tad less as didn't top it off like I did on the prevous tank.....so maybe 47 and up. Should/could be better methinks....

Click to expand...

Fill it up and totally top it off all the way to liquid at the top of the filler neck. Give it a healthy dose of PowerService Diesel Fuel Supplement (white bottle) to take care of any water from condensation. Don't use PowerService Diesel Kleen (silver bottle) because it doesn't do anything for water. My other favorite additive to use is Howes Lubricator Diesel Treat.

Do not use ATF because it is lousy as a diesel fuel additive. 2-stroke engine oil is great for lubricity but doesn't do anything for water. Do not use Stabil because that is for gasoline.

Good luck and Welcome to TDIclub.

Having kept VW diesels stored since the early 1990s I can say water and the critters that love to eat the diesel fuel are the enemy of long term storage. In the early 90s I brought a car to Colorado that had over the last couple of years only been driven when I in NC. In the first cold spell, the critters in the tank were killed. Soon after they began to flake off completely clogging my fuel system. It took a month of flushing the fuel system to get the car going right again, much time spent on the side of the road....

I learned to keep the fuel tank filled to the brim with treated fuel, overtreated fuel with a good killer of the things that love to thrive in untreated fuel. Today and for the last ~25 years, I have not once since experienced issue from long term diesel vehicle storage....

Right now I have two cars stored like this that recently after years of not being driven were used for hundreds of miles clocked when needed with nothing but a new battery needed. they both cranked right up when a new battery was installed...

good luck

Go find a truck stop and get a jug of ClearDiesel from Power Service. Yes, that is the same company that produces the silver bottle and white bottles of DieselKleen.

ClearDiesel is an anti-slime agent that will prevent buildup in old fuel. Otherwise, you pretty much don't need anything. Even gunked up fuel (like 5-6 years old) will still run the engine, but your fuel filter won't be happy about it for long. That is what the ClearDiesel is for, to try and break up the slime... And send it into the filter.

You don't need much, only add LIQUI MOLY "Super Diesel Additve"

I avoid biodiesel because it tends to attract more water and spoils much faster than regular diesel.

FiveFilter said:

I avoid biodiesel because it tends to attract more water and spoils much faster than regular diesel.

Click to expand...

If treated properly a mix of BD & D2 (~B20) will last just as long as regular D2, but the mix will keep the system cleaner inside the tank.... BD is an excellent solvent so does a really good job of keeping the tank clean....

Geordi said:

Go find a truck stop and get a jug of ClearDiesel from Power Service. Yes, that is the same company that produces the silver bottle and white bottles of DieselKleen.

ClearDiesel is an anti-slime agent that will prevent buildup in old fuel. Otherwise, you pretty much don't need anything. Even gunked up fuel (like 5-6 years old) will still run the engine, but your fuel filter won't be happy about it for long. That is what the ClearDiesel is for, to try and break up the slime... And send it into the filter.

Click to expand...

i've never used ClearDiesel but i will concur that 5+ year old fuel will run the engine just fine in warm weather.

in my current Passat, which had been sitting at least 5 years according to registration info, it ran fine until i filled it up for the first time and the sludge mixed up in the fresh fuel and plugged my filter.

i'd say just store it with a full tank to avoid condensation and it should be fine to sit 6 months to year.

The only reason I bought ClearDiesel is b/c I have a 40' diesel RV that had been parked for an unknown amount of time before I bought it, then I drove it to a place and it was parked again for about 2 years while I was working on the interior and living in it on-and-off... And when I started to actually use it for a long trip (evacuating from hurricane Matthew) the filter suffered and died pretty quick.

What came out of the filter is best described as pond slime. YUCK. Poured a jug of CD into the tank to break up the slime, and it ate filter #2 inside of 200 miles. Another jug, and filter #3 has been doing alright since then - although it probably could use a replacement just because. My generator also ate two filters probably b/c of the same slime.

Only add the finest of snake oils.

That is, park it and forget about it.

i've had cars stored for 5+ years now. no additives, just turn the key and go

haha not that simple. I pull spark plugs, add a bit of oil, let it soak in overnight. come back and crank it over withouth spark plugs (no compression) to expel any leftover oil that didn't seep through. put the plugs back in, crank and enjoy the ride.

i wouldn't do anything special besides unhooking the battery and putting it on an automatic charger.

Thank you all for the many great answers and taking the time to post on my question. I think I got 'er did.......uh.....Power Service Diesel Fuel Supplement for to take care of any water condensation. And....Power Service Clear Diesel to take care of any slime and build up of old stuff.......