Hey guys, I'm in the market for a new truck, and I've been looking at the 2500HD series. But before I buy, I've got a few questions, and I'm hoping that someone here might have an awnser.

1. Do the Duramax Deisels come with a turbo like the Ford and Dodge deisels do.

2. Are the new 5spd allison trannys a decent tranny.

3. What type of mileage can i expect to see on the deisel vs gas.


Thanks guys!

 

Duramaxes have turbos and the Allison is the sweetest trans GM has ever put into a light truck. You can expect mileage averaging 24 and see top out around 28mpg.

....or you could buy an 8.1 with the same trans, get 11mpg, and consume a quart of oil every 1500 miles.

 

1. yes, a diesel without a turbo is just a turd.
2. yes, it's probably the strongest light truck trans out there right now. it's also geared very well, just a bit noisey.
3. most duramax's are getting around 21 average and the others are around 9-16 for gas (generally around 12).

 

Thanks for the replies guys.

How about lifeline on the motors, duramax vs the 6.0 how long will each last under normal day to day usage.

 

i agree with the above except i STRONGLY disagree with the milage. yes it depends on how you are with teh go pedal but you arent going to get 20 mpg consistently. not even close. expect 18 mpg on the highway 70 mph. with a juice or programer expect it to gain 2 mpg. and this is on flat ground. sorry to disaapoint. amazing truck though from personal experience.

 

Gator is right about the mileage. 18mpg can be had pretty consistently on the highway. Saw about a 1 mpg gain with the Juice on level 1.

The engine and transmission are very smooth, takes no time at all to get used to it after driving gas engines all my life, very nice setup.

 

I have never gotten 20 mpg or higher in my truck in 16k miles and almost a year of having it. I've seen 19 a few times though on trips, though. Around town I am usually somewhere around 16 mpg, but let's just say I get my moneys worth out of the 125 hp juice. My 33 inch mud terrains are probably hurting my fuel economy some.

 

Why do the 8.1s use oil?

 

Come to think of it, all the guys I know running Duramaxes have propane injection. That might explain the milage.

The big blocks have oil consumption issues due to intake manifold gasket sealing problems. Oil from the intake area literally gets sucked into the ports. There was also a problem with PCV (also on earlier Gen-II engines) where oil was being drawn out. The PCV issue has been addressed with orifice-type regulation, but as far as I know the intake gasket problem still plagues some new trucks.

On the subject of gaskets, GM recently introduced a new Vortec 305/350 intake manifold gasket with several design changes to help combat the failures that every one of these motors eventually experiences with these damn gaskets. You Gen-III and LS1 folks have it much better when it comes to intake gaskets! I guess I'd rather have leaks than piston slap!

 

Anywhere between 14-18 is more reasonable for city and highway.