To LLY or not to LLY?

[Vivayo]

I still have the truck in my sig, but am thinking about upgrading to diesel. I really like everything about my truck except the motor. No specific problems (in fact, none in the 19,000 miles on it), but wish I'd gone with the Duramax/Allison combo when I bought it. I see posts about problems with the LLY and wonder if I should wait to see if GM gets it right, or are the cases infrequent enough to not worry? Figured the best place to get a straight answer is right here.
Charlie

[4diesels]

Do you have the 6.0L or the 8100? I am personally not convinced that the D/A is an upgrade anywhere but on the window sticker :eek: My duramax gets 13-14mpg empty and about 9 while towing. Takes a very long time to pay for a $4500 engine at that rate. If you have to run in the mountains the turbo diesel is nice, much less power loss and the grade braking is nice.

Looks to me like there are still issues with the LLY. Judging by the poll on the 6600 forum, you have about a 1 in 10 chance of getting an injector problem. I will be going back to a gasser on my next personal truck.

[Jim Dandy]

I understand your dilema. I just purchased an LLY. Have been very disappointed in MPG. I drive 100 miles round trip for work daily. Last night I disconnected EGR and on my 50 mile leg this a.m. my DIC MPG came up .7 MPG. It would normally have stayed about where it was or dropped slightly. I'm about half way thru a tank of fuel. Assuming I get a 1 MPG improvement for the EGR delete and accounting for larger tires, I'll be at about 15 MPG. My juiced LB7 will get 20 MPG on the same drive. New truck only has 1200 miles so am hoping for further improvement in MPG over the coming months.

[Vivayo]

4diesels & Jim:
I have the 6L. Fuel mileage wasn't a primary concern when I bought it and still isn't. I'm getting near 15MPG hiway and ~12-13 on local running around. We just upgraded our TT to a 33'er and I was thinking about a stronger tow vehicle. That said, the dealer delivered it with a truck similar to mine (2500HD 6L/CC/SB) and the driver said it towed very easily. We keep the TT at a year-round site and rarely move it, so mountains won't ever be a factor.
Given the possibility of trading a truck I like for one with problems, I think I just talked myself out of it :confused: Thanks for the sanity check.
Charlie

[4diesels]

I think that the 6.0 has been a very good engine for GM. It has good power and I understand they have been very reliable. I'm not saying the d-max is a big risk for problems but given the huge price difference and marginal milage benefit I would run the 6.0 unless I really needed the power for mountains.

[OC_DMAX]

Vivayo,

I upgraded to my current 2002 DMAX from a 2000 Chev 2500 that had a 6.0 L gas engine. The 2000 6.0 L engine was a good one.

My observations:

The 6.0L engine never got what I would consider good mileage. About 12 mpg around town and 16 mpg on the highway. Pulling a smaller travel trailer (7K pounds), the mileage varied from 9.5-10.5 mpg. The DMAX (LB7 variety - with CA EGR/CAT by the way) gets 15 mpg around town and 19 mpg on the highway. Pulling the same trailer combo to the same campsites, it consistently gets 12.5-13.0 mpg.

As 4diesels mentions, you will never get back the dollar difference in purchase price (DMAX/Allison combo) from fuel consumption differences alone. Also, there is ALWAYS that possibility of the $4K repair bill for the injectors that go bad. I have a 7yr extended warranty on my DMAX. The DMAX will be traded off before that warranty expires. I do not want the possibility of a $4K injector repair bill hanging over my head. THE INJECTOR COST IS THE HUGE DOWN SIDE IN OWNING THESE TRUCKS.

Again, to the positive side. The DMAX tows SO MUCH BETTER than the 6.0L truck did. NO COMPARISION (especially with the Edge Juice or TTS programs). The 6.0L was alway down shifting and running to 4000 RPM. I really like the way the DMAX tows. It is really effortless with what I am pulling (and we have some really big grades to climb out west here in CA).

Personally, I am waiting for 2006 to see what pops up. I have heard bits and pieces that there will be some "neat stuff" happening on the DMAX/Allison combo. If this does not materialize, then I'll probably trade for a Dodge RAM/Cummins combo (and give that a try!).

For your situation, if you do not routinely tow the trailer, just stick with what you got. When it comes time to update (and that time always comes around), then consider the diesel model. Maybe even purchase a GM extended warranty to relieve some of the injector anxiety (assuming they have not fixed the issues by then).

Hope the above helps,
Alan

[ 08-21-2004, 02:54 PM: Message edited by: OC_DMAX ]

[Vivayo]

4diesels & Alan:
Thanks again for the advice and personal experiences. The fever has passed, so I think I'm safe (until it hits again). SWMBO 'suggested' I wait a year. I guess there's a reason we've been married for 36 years...
Charlie