[terryjm1]

I “heard” that GDE enabled DEF usage (albeit reduced) in their final tunes before they switched to compliant tunes only.

Can anyone confirm that?

Thanks in advance.

Terry

 

[tex2018]

That is correct

 

[terryjm1]

Any idea how much you go through over time?

 

[tex2018]

Any idea how much you go through over time?

Hard to say, .. but it's fairly low consumption . I'd guestimate that a 2.5 G jug of DEF lasts about 4000 miles, perhaps more

If I can find some time, I'll try and look up the pegged value for the DEF consumption PID (223348)

 

[bigoilbob]

Hard to say, .. but it's fairly low consumption . I'd guestimate that a 2.5 G jug of DEF lasts about 4000 miles, perhaps more

If I can find some time, I'll try and look up the pegged value for the DEF consumption PID (223348)

My stock as a rock DEF consumption hovers around 60 gal diesel/gal DEF. I have OCD'd over 60K miles worth of fuel stops and DEF adds, so I think this is a fairly good number. At 25 m/g you would be using ~64 gal diesel/ gal DEF. Essentially the same.

 

[Duken4evr]

I “heard” that GDE enabled DEF usage (albeit reduced) in their final tunes before they switched to compliant tunes only.

Can anyone confirm that?

Thanks in advance. Terry

Earlier GDE tunes had DEF disabled, which required draining the tank every two years or so, as it would go stale and evidently throw a poor DEF quality code. I did drain the DEF tank once and it was a moderate PITA. We customers asked GDE to enable DEF dosing to avoid this hassle. Plus I suppose the exhaust is a little cleaner too.

With DEF enabled, I am averaging about 1,000 miles per gallon of DEF. I put in a 2.5 gallon jug when it hits 30% and that occurs right around every 2,500 miles or so. This is general driving, with no heavy towing. If I do run out of DEF, it displays this in the DIC, so no big deal if it is not convenient to get more - I can live with a 124 MPH max speed

Speaking of speed, I heard the older tune removes the speed governor. Dunno if the compliant tune removes the speed governor or not. Have not tested the 124 MPH top speed theory, done some 90 MPH cruising in Utah and Wyoming on the 80 MPH open roads in those places (cars going 90+ is not uncommon at all in those places), but don't think I have ever gone 100 in the truck, that would be a little silly eh? It does 90 very nicely though, locked out in 6th at around 2.3K RPM. Even at that speed, if there is no headwind, it is breaking 20 MPG easy.

On my last dirt bike trip, a 5.7 V8 Tundra owning buddy was riding shotgun, and he was floored how the 2.8 just hums quietly along at ludicrous speed on the open road, never downshifting. We were in Utah, doing 85 with the cruise set, 2 bikes in the bed, and the fuel economy screen was showing a steady 24 MPG. I love this engine.

 

[tex2018]

Hard to say, .. but it's fairly low consumption . I'd guestimate that a 2.5 G jug of DEF lasts about 4000 miles, perhaps more

If I can find some time, I'll try and look up the pegged value for the DEF consumption PID (223348)

All I could find was DEF consumption per hour. I just filled in some DEF a couple of days ago at 60K miles when the 1000 miles warning showed up . I'll see how long before the next warning and post back.

Might be a while, given that I've cut down on driving on account of high fuel costs

 

[Cutterman]

I’ve used 0 gallons of def in 45k miles after GDE tune. I also have blown engine with 69k miles on engine. GDE fault or not who knows.

 

[terryjm1]

I’ve used 0 gallons of def in 45k miles after GDE tune. I also have blown engine with 69k miles on engine. GDE fault or not who knows.

Wow, that is a real bummer. Do you know which version of the GDE tune you used? (Update number?)

 

[Cutterman]

My post was half sarcastic. I have the old delete tune… explains the no def, but did the tune cause the cylinder to go. If you do enough research you will find many GDE tuned trucks that lost cylinders than non tuned. Their fault or bad GM design who knows.

 

[SFLTruck]

My post was half sarcastic. I have the old delete tune… explains the no def, but did the tune cause the cylinder to go. If you do enough research you will find many GDE tuned trucks that lost cylinders than non tuned. Their fault or bad GM design who knows.

What year is your truck?

 

[GreenDiesel]

My post was half sarcastic. I have the old delete tune… explains the no def, but did the tune cause the cylinder to go. If you do enough research you will find many GDE tuned trucks that lost cylinders than non tuned. Their fault or bad GM design who knows.

Look harder. 2016-2018 engines have injectors that fail and blow holes through the piston. It is not a tuning issue and happens quite regularly on stock tuning. This issue was resolved by GM in 2019 when they changed the injector design. We have not heard of any 2019+ engines failing pistons.

 

[terryjm1]

Wondering if a preventive injector replacement would be a good idea at some point. I know we cant replace the old style with the new style but even new old style injectors might be a good idea.

 

[Cutterman]

Why can’t you replace the old style with new style?

 

[tex2018]

Why can’t you replace the old style with new style?

They are not interchangeable, unfortunately. Keep in mind that the failure rate is still extremely low.

That said, are there any proven injector solutions for those of us that have older Colorado's .

 

[terryjm1]

They are not interchangeable, unfortunately. Keep in mind that the failure rate is still extremely low.

That said, are there any proven injector solutions for those of us that have older Colorado's .

I am surprised the aftermarket hasn’t been more active with our diesels.

 

[Cutterman]

I was planning on using these during my rebuild.

 

[SFLTruck]

Why can’t you replace the old style with new style?

They change the injector physical design which now uses a different head to accommodate fitment.

 

[DKinney]

I threw in a GDE engine and tranny tune at 7000 miles. To this day I have never had to add or drain any DEF. The DIC has displayed 25% for the past 4 years. I'm over 90k and will run this truck (God willing) into the ground.

 

[SFLTruck]

I threw in a GDE engine and tranny tune at 7000 miles. To this day I have never had to add or drain any DEF. The DIC has displayed 25% for the past 4 years. I'm over 90k and will run this truck (God willing) into the ground.

What year is yours?