New GMC Truck?

[captbanjo]

I've been reading TAKPAK's thread on his new GMC truck with interest (I sent you a PM). I currently own a 2004 GMC Sierra that I had extra springs put in for the increased tongue weight in our new RV we bought, a 3750 FL. I've noticed no issues so far. I am planning to buy a new one, maybe at the end of this year.

For you who speak truck, would a four wheel model ably pull a 3750 FL? I've also been learning about the DEF system and that sounds like a new pain to contend with too?

Thanks!

[TAKPAK]

Sent you a PM, Wayne.

TK

[BB_TX]

Do you mean four wheel as opposed to a dually (six wheel)? New 350/3500 SRWs have enough payload capacity to handle a 3750RL. A DRW (dually) even more.

DEF is really not a problem. Mine has a 5 gallon DEF tank. I add 2 1/2 gallons about twice a year, driving about 10,000 miles per year. Most of that is not towing though. Towing will increase the usage, but still not something you have to add regularly. I buy the 2 1/2 gallon jugs from Walmart or at auto parts store. But many fill up at stations that have it at the pump.

[captbanjo]

Yes, I meant four wheel as opposed to six, as it will be a travel vehicle as well as towing. I'll probably also opt for four-wheel drive as I'm in New England (hey...how 'bout them Pats!) and will probably need it eventually. My present truck doesn't have it and my understanding is that by adding four-wheel drive you lose some mileage.

So the DEF must have some sort of gauge? Or do you just change it out at the right mileage? And what if you don't...what might happen?

quote:Originally posted by BB_TX

Do you mean four wheel as opposed to a dually (six wheel)? New 350/3500 SRWs have enough payload capacity to handle a 3750RL. A DRW (dually) even more.

DEF is really not a problem. Mine has a 5 gallon DEF tank. I add 2 1/2 gallons about twice a year, driving about 10,000 miles per year. Most of that is not towing though. Towing will increase the usage, but still not something you have to add regularly. I buy the 2 1/2 gallon jugs from Walmart or at auto parts store. But many fill up at stations that have it at the pump.

[mhs4771]

You don't change the DEF, it's injected into a special converter to reduce some of the emision and is used in direct relation to amout of fuel used. If you run it out, it will shut you down, to like 4 or 5 miles per hour till you refill it.
Don't be afraid of a Dually, that's all we have and we take it everywhere. 4X4 might reduce the mileage a little, but we average 10 to 10.5 pulling 17.5K, 13 to 15 around town with stop-n-go, and 17 to 20 solo on the open road.

[1retired06]

Def is no big deal. Don't know if GMC has reconfigured like ford or still fills under the hood.

[stengels]

DEF still fills under the hood, but not a real problem. Regarding the 4WD, I only use mine when conditions call for it. Pulling down a dry interstate at 68 mph (1700 RPM) does not require 4WD.

[BB_TX]

You just add DEF as it gets used up by the emission system. But that is not very often. Seems people tend to report having to add DEF about every 5,000 miles when not towing. A little more often if doing a lot of towing. DEF has its own tank independent of the fuel tank.

Don't know about GMC. Ford does not have a gauge. You can check the status in the info screen and it will state OK, less than 1/2 full, or something else if it gets too low. If it does get low enough a warning message will pop up warning that you need to add DEF soon or it will go into limp mode meaning it will still run but at reduced power.

[mhs4771]

Reduced power would be one thing, but at 4 MPH you're dead in the road. And just an FYI the MFRs had nothing to do with that, it's directly from the Feds

[MIMF]

Wayne, you can see in my signature what I have. If someone was to attempt to take it from me......may the Lord have mercy on his soul! As far as the DEF, I have had to buy a 2 1/2 gallon jug once in the year that I have had this truck. Otherwise, when I take him in for service, the dealer tops off the tank for me. ........for free!

[WeBeFulltime]

I purchased my truck used 7 1/2 months ago with only 4,300 miles on it. It now has 11,100 miles and have not had to add DEF yet. The dealer topped off the fuel and DEF tanks on delivery. Very small amount of theses miles are towing.

[Rondo]

David-- I'd be buying a 2 1/2 to 5 gallons of DEF and put it in. If you have had it serviced at a dealer since you bought it, it is more than likely they have topped off the DEF each time you've had it serviced and that is why you have not had to put any in your truck. If you have not had it serviced at a dealer then you've got a problem because with nearly 7000 miles on it whether you are towing or not the DEF should be down to nothing in the tank. Most trucks average about 5000 miles per tank of DEF. I've got a 2012 Silverado and use it both for towing and regular driving around Omaha and back and forth to the farm which is 45 miles away and I go through a 5 gallon tank of DEF on an average of 5000 miles driving. It will use more if towing as I've found out on several trips with the Monte. One trips, I carry a 2 1/2 gallon jug of DEP in the bed just to be on the safe side. It can be bought at any truck stop, auto parts store or even Wally World!

[Tom S.]

The GMC/Chevy has a warning that tells you when you get down below 1,000 miles left of DEF, so running out isn't a problem.

[captbanjo]

Thanks for all the info. Very helpful!