Watch out all you 6.2 gas folks, we're comin for ya!!!

[AXE]

I test drove the 3.0 while I was exploring options and at the time, was all I could find anywhere. Sooooo glad I waited to find the 6.2 with the options I wanted. Not even a comparison. Like the dealer trying to convince you the 4 cylinder is just as good as a V8. Never been a diesel guy, never needed to tote a house around with me. The 2500 ZR2 would probably be my only sway point and that's just because that's as big as you can be lol.

2500 has a gasser option too.

 

[McManly]

Yep, I’ve had a zr2 with both and it’s all about use cases and personal preferences, that’s actually the beauty of having options.

Either way, grip it and rip it

I've had 2 hellcats (hellcat manual and redeye), have a bmw m50i and a McLaren GT, so I love v8s for their sound and power, no doubt. So it was quite the change for me to get the 24 ZR2 with 3 liter duramax. Freeway power is way down, but few here talk about how satisfying slight throttle take-offs are with all that torque. Hard throttle from 0 is not slow by any means, but it is so nice to barely press on the gas and have this satisfying amount of acceleration around town. I just finished ripping it up at Jawbone Canyon (for those of you who know the area) being a chase vehicle for my son and his buddy on their dirt bikes and off-road torque is awesome. Then I get back on the freeway and watch the mpg rise to 26 with 2 kids and 2 bikes, ramps and a generator in back along with all of our stuff. Not to mention 550 mile range. Talk about a great motor. I love gassers but this being my first diesel, I'm loving it for what I bought it for.

 

[badbarts52]

I have had 3 of the 3.0 Duramax trucks and having nothing but good to say about them, only small hassle is the DEF fluid thing. Great mileage. My current 6.2 is certainly quicker but does average 8 mpg less on my regular commute route.

What is everyone getting for DEF mileage on their 3.0s???

I just took a trip through Michigan with a 14ft aluminum trailer and two quads. Running about 80-85mph most of the trip.

My fuel mileage was around the 12-13mpg mark, but I burned through 5.5 gallons of DEF over the 820 mile trip. That seems pretty crazy?

The truck told me it was out of DEF twice, but both times when I filled up, I was only able to fit about 2-3 gallons in the tank.

 

[securityguy]

What is everyone getting for DEF mileage on their 3.0s???

I just took a trip through Michigan with a 14ft aluminum trailer and two quads. Running about 80-85mph most of the trip.

My fuel mileage was around the 12-13mpg mark, but I burned through 5.5 gallons of DEF over the 820 mile trip. That seems pretty crazy?

The truck told me it was out of DEF twice, but both times when I filled up, I was only able to fit about 2-3 gallons in the tank.

Not apples to apples, but my 6.6L DMAX now has over 1000 miles and I've regened twice and have used 1/8 of my tank of DEF.

 

[AXE]

What is everyone getting for DEF mileage on their 3.0s???

I just took a trip through Michigan with a 14ft aluminum trailer and two quads. Running about 80-85mph most of the trip.

My fuel mileage was around the 12-13mpg mark, but I burned through 5.5 gallons of DEF over the 820 mile trip. That seems pretty crazy?

The truck told me it was out of DEF twice, but both times when I filled up, I was only able to fit about 2-3 gallons in the tank.

Seems excessive, 1 gallon per 1000 miles is a rule of thumb! That'll drop some towing. I would have it checked. If you're burning that much, there is a problem. You'll plug up your DPF more quickly too.

I think I'm getting about 1 gallon per 1200 miles on my 2500HD ZR2. Besides what the dealer added minimally at sale time, I've only added 5 gallons and still have a half a tank of DEF after 6k miles. That includes a lot of mixed driving and towing.

 

[LSnTX]

I don’t think you can get an estimate from one trip. You should track DEF consumption by gallons of fuel burned to get a percentage when empty, then you can compare to towing. Towing is a wild card, terrain, wind weight, speed,and you were ripping that rig , which is slightly more aerodynamic than a brick at close to takeoff speed, not knocking your driving or decisions, but I wouldn’t expect any numbers rollin at that speed.
LM2and LZO, sips DEF when empty and does drink more when towing.
Your consumption may have been high, but the gauge and filling from the jugs will not give you total accuracy either. It’s not an equation to plug in.

 

[NullNomad]

I’d add that idling will drink the ever living sht out of DEF as well…

 

[Tdbmd]

What is everyone getting for DEF mileage on their 3.0s???

I just took a trip through Michigan with a 14ft aluminum trailer and two quads. Running about 80-85mph most of the trip.

My fuel mileage was around the 12-13mpg mark, but I burned through 5.5 gallons of DEF over the 820 mile trip. That seems pretty crazy?

The truck told me it was out of DEF twice, but both times when I filled up, I was only able to fit about 2-3 gallons in the tank.

I did find that the 3.0 used more DEF when working harder, like towing than when just driving. I have towed SxS on aluminum trailers and generally would average around 18 mpg but not driving those speeds, more like 65-68 mph. Driving fast kills fuel economy, whether towing or not

 

[RCF71]

Seems excessive, 1 gallon per 1000 miles is a rule of thumb! That'll drop some towing. I would have it checked. If you're burning that much, there is a problem. You'll plug up your DPF more quickly too.

I think I'm getting about 1 gallon per 1200 miles on my 2500HD ZR2. Besides what the dealer added minimally at sale time, I've only added 5 gallons and still have a half a tank of DEF after 6k miles. That includes a lot of mixed driving and towing.

My DEF usage is very similar, and thats better than I thought it would be.

Help me out on the first part though, not sure how the additional DEF usage impacts the DPF - it injects downstream of the DPF right? Or are you saying the engine efficiency being so much lower equates to worse emissions (soot, NOx, etc) which fouls the DPF sooner and causes more DEF to be used?

 

[AXE]

My DEF usage is very similar, and thats better than I thought it would be.

Help me out on the first part though, not sure how the additional DEF usage impacts the DPF - it injects downstream of the DPF right? Or are you saying the engine efficiency being so much lower equates to worse emissions (soot, NOx, etc) which fouls the DPF sooner and causes more DEF to be used?

Actually,I had a memory lapse, I was thinking the DEF was was injected into the slipstream pre DPF. But that's the 9th injector off the downpipe for fuel to burn the soot off in the DPF.

But yeah, if your burning more fuel, the DPF fills quicker and you burn more DEF.

This diagram is for the 3.0L Duramax.

 

[RCF71]

Ok, cool - that was my thinking but thought maybe I was missing something!

 

[DNZR2]

Actually,I had a memory lapse, I was thinking the DEF was was injected into the slipstream pre DPF. But that's the 9th injector off the downpipe for fuel to burn the soot off in the DPF.

But yeah, if your burning more fuel, the DPF fills quicker and you burn more DEF.

This diagram is for the 3.0L Duramax.

@AXE Thanks for the diagram. The wife just got the 3.0 in her new 1500 LTZ and it is our first diesel so I’m trying to understand how everything works.

 

[badbarts52]

I did find that the 3.0 used more DEF when working harder, like towing than when just driving. I have towed SxS on aluminum trailers and generally would average around 18 mpg but not driving those speeds, more like 65-68 mph. Driving fast kills fuel economy, whether towing or not

Thanks everyone for the additional info!

I’m going to ask the dealer about it too to see their input. I’ll continue to monitor the DEF level during daily driving as well as on road trips with a trailer. And maybe when I’m not hauling ass!

 

[ZR2BIZON]

@AXE Thanks for the diagram. The wife just got the 3.0 in her new 1500 LTZ and it is our first diesel so I’m trying to understand how everything works.

It doesn't.
Sorry to hear about the bad decision my friend

 

[DNZR2]

It doesn't.
Sorry to hear about the bad decision my friend

@ZR2BIZON She even doubled down and got the wrong color to boot. White.

 

[ZR2BIZON]

Welp. Atleast you guys got the color right!

 

[AXE]

Welp. Atleast you guys got the color right!

I'm from the government and I'm here to help!

#whitey

 

[NullNomad]

@ZR2BIZON She even doubled down and got the wrong color to boot. White.

She sounds like the smart one of the couple that’s for sure!!

 

[Tdbmd]

Motor Trend just recently set out to see what kind of range they could get with their ZR2 Duramax 3.0. 826 miles on one tank! Pretty impressive.

https://www.motortrend.com/reviews/2024-chevrolet-silverado-zr2-duramax-diesel-yearlong-review-unbelieveable-fuel-economy/

 

[AXE]

I seen that earlier today. Looks pretty impressive. Maybe the aero isn't so bad and it's just the ac killing mileage on these rigs. I've run my AC in the winter in the afternoons. It gets a tad hot inside in the summer.