GM Drive for a Cause

I have some friends at my local GM dealer even though I'm a long time Ford guy. They are donating $30 for each test drive for every test drive to local charities. I took out a Duramax as my first diesel truck experience and it was tempting to sign the papers.

Are there any years of concern? This was a 2012 loaded Z71 4X4 with the exhaust brake and 70,000 kms (40,000 miles).


Sent from my iPhone using Tapatalk

Most of all the DMax years are fairly good. Lots of improvements in the engine and trans from model year 2006 forward. Dmax's, like the others, also suffer from aggressive EGR application.

I love my 2012 except when it goes into the regen mode to clean out the DPF. When it does I drop average 3 mpg and get a high idle (which can't be good for the drive train and brakes) for about 50 to 70 miles before it goes back to normal.

I haven't followed any of the D'max stuff since selling my 06. But, staying in regen for 50-70 miles sounds wrong. And high idle should not be activated if the vehicle is in gear.

But, staying in regen for 50-70 miles sounds wrong. And high idle should not be activated if the vehicle is in gear.

Click to expand...

Mine has done this since day one. I have a friend with the same truck I have only a 2011 and his does the same thing.

I also have a 2012 3/4 ton 4by4. The truck pulls my Bighorn like a freight train.
No problems. With it to date. The regen is a little annoying, but you get used to it.
Running light from Illinois to Texas at 70 to 75 mph we averaged 21/22 mpg
Pulling the Bighorn gets 10.5 to 12 mpg depending on terrain and wind conditions.
Overall I am very satisfied with the truck.

When they say high idle they mean, the idle goes from 500rpm, to around 800 rpm during regen. Mine does the regen thing, but I dont drive my 2011 enough to keep track of it. Just as a note for the OP, the duramax equipped trucks from 2011 on had the built in exhaust brake which is great!