Truck just sitting?

Yep, biodiesel is said to have half or even less the shelf life of regular diesel. It tends to hold and attract more water which can lead to microbe growth and corrosion. The bio part of biodiesel can come from a variety of sources that can have questionable quality control and a much wider range of components. I would stay away from it, especially if it is not going to be used up pretty quickly.

Mine has sat for up to 5 months at a time, never any problems. When I let it sit that long, I fill the fuel tank.

Don't leave it parked with any biodiesel in the tank for extended periods, as per GM. GM manual section 9-22

I avoid that problem by not using that stuff in my HD. For long term battery storage, my go to device is a Battery Tender. Been using them for 15+ years, great product.

Travelnutz wrote:
Probably helps a lot that where we live in West Michigan on the lakeshore we don't get below zero F at night or over 90F max as that can really hurt battery life etc.

Hi Travelnutz!

Its hard to believe how long these batteries go. I'll probably replace the other in 2017.

Our truck was only stored outside for 1 winter since new. Other than that, its only seen heated storage, and the occasional coolish spring or fall. It had seen 2 expeditions to the Southwest for 4 weeks each. But even those excursions were during spring; so no exceptionally hot prolonged life in the baking heat.

We do indeed have the same trucks (down to the color LOL!), albeit, yours is diesel. We have ~67k kilometers so far hah hah! I've seen these trucks go to 400k miles(!) quite often. Our undercarriage looks like showroom (I coat it every year myself since new). We expect it to go perhaps 15 to 20 more years, it will then be insured as vintage collectable (I hope gasoline will still be available then hah hah).

Cheers,
S-

Grit dog wrote:
Weeks or months, don't worry about it.
Year or years, do something about it.

I will second this . Diesel is not nearly as troublesome as gas for aging , the biggest concern would be algae , it can really mess up a fuel system . I would keep the tank full to limit condensation and use a biocide additive for long term .

GMC says not to use additives.
Also have Kubota and Caterpillar diesels that don't get used for six months
to a year and they have no fuel issues.

silversand,

As you know, we have a 2004.5 Chevy also but it's the 6.6 diesel (D/A) which has 2 big starter/acc batteries also. Just replaced the OEM batteries last year at 11 years old and over 160K miles. Still started the truck fine but sure didn't want to be somewhere with 2 dead batteries so it was time! Never disconnected them once as the truck (only used since new for RV use with either the Lance TC on or our Carriage Carrilite 5th wheel) very rarely sits idle for even a week.

Heck, I never disconnect the boat batteries for storage from around the first week in November till in May and they are 8 years old now. NO battery minder ever used and the engine starts right up always. Don't disconnect our RV's batteries when in not used season either and have never used a battery minder. Never had them go dead or below 70%. Just fully charge them before storing! All our very MANY (11) batteries are the flooded lead/acid 12V and most are group 31 deep cycle 215 to 225 minute reserve at a 23 amp draw except the truck and SUV starter batteries.

Probably helps a lot that where we live in West Michigan on the lakeshore we don't get below zero F at night or over 90F max as that can really hurt battery life etc.

A battery tender helps. I have a small solar powered one in the window of the garage plugged into the cigarette lighter socket that keeps me topped off.

Dual battery Silverado 2500HD here (non diesel). Our truck sits in storage for 7 to 8 months a year (this year an early spring, so only 6 months storage). I stopped using the battery minder probably, hmmm, 8 years ago. I now just disconnect my 2 batteries for storage (it takes me only ~2 minutes to disconnect them), and I disconnect them if we have no driving planned for more than a week. The truck is a 2004.5; and starter battery is still original. After 12 years, it is still like nearly new condition. I've only replaced the accessory battery; that was done last year (at 11 years old) LOL!

...OK, back to the program...

Diesel quality and longevity can vary greatly across the country. Some regions can promote algae growth much quicker than say the Southwest.

Personally, I pour additive into every tank to boost cetane and inhibit potential growth. I've had fuel sit for over a year without issue.

If treated, diesel can sit for up to 5 years. This is one reason why large diesel generators are preferred over gaz0line.

billtex wrote:
Our truck is not a daily driver...I ride my bike to work. The truck can sit for weeks at a time all year long.
I have never used any diesel fuel treatment. Fuel at the pump is blended for the proper season already.
Truck starts right up and goes.
No worries...

Bill

X2. My truck is for hauling the camper, the occasional home project and foul weather 4x4. Sitting for 4-6 weeks or more is not uncommon though I start to get nervous around 6 weeks and try to take the truck for a drive just to keep parts lubricated, not just engine but drive train. Even so I still usually use a couple tanks/year so the age of the diesel isn't a concern. A battery tender helps. I have a small solar powered one in the window of the garage plugged into the cigarette lighter socket that keeps me topped off. Also, when I do give the truck a lube drive I make it long enough that allows the engine to get up to temperature to get rid of any condensation inside the block. Then it's back into the garage until I need it again.