Thinking about a diesel

[PerfectReign]

In looking at the Silverado/Sierra, I noticed a lot of peeps glowing (no pun intended) about their diesel engines. In fact, I was reminded of my old dentist who had bought a 6.5 suburban way back when to tow his two show cars. (’48 packard and ’57 bel air) He used to talk about how much better the truck was than the gas version, which he had previous.

Okay, I’m almost sold. Sounds like the LBZ engine is what I’d be getting, right?

I first looked at the gmbuypower site to see what the sierra was when configured with the Duramax. It showed only a 6 speed manual transmission available for the truck. I then checked out the Chevy specs and found they offer either the four-speed or six speed automatic tranny.

Does anyone know if the GMC truck has an optional automatic tranny? I’d be also curious why the difference.

I’ve always liked the idea of diesel, especially if I can get biodiesel and still utilize the extra 300 ft/lbs of torque over a gas engine yet still expect 200,000+ miles out of the engine. What are your opinions for someone who will be using the truck as a daily driver and only doing light towing? Is the diesel worth it over the gas engine? I noticed that on this forum and on thedieselpageforums people seem to get about the same mileage with the Duramax as with the 5.3 Vortec. That is an incentive, since I’d be getting the same mileage with way more power.

Also, is there a problem finding mechanics who can work on these engines? I would wonder how many are available for down the road. I’m curious, too, if the new fuel will be an issue. I have been reading about new low sulphur fuel coming out. Is there going to be a conversion needed?

One final question – I’m in southern California where it can get very warm:
http://www.perfectreign.com/?q=node/15

Diesels like this, right? IIRC, diesels do better in the heat than gas engines. Is there a problem running diesels in semi desert areas? I haven’t test driven a duramax Silverado/Sierra yet but plan to very soon.

[K5Fury]

I can maybe answer some of your question. Diesel do get better mileage than gasser but only slighty unloaded. If you are pulling then that is when the really big mileage difference comes in. A diesel for a daily driver that only gets used occasionaly to tow would last forever. As with any vehicle the less strain on it the better off it is. The new fuel will not have any affect on current diesels. However, '07 diesels cannot run on the diesel being produced right now. Think of it when we went from leaded to unleaded. Get the Allison transmisson and don't look back! Warmer climates are fine for diesels and you won't have near as long a wait for the glow plugs to warm. Hard to say about diesel mechanics in your area, best advice is to get the yellow pages out and look around. Once you buy one, you will be hooked!

[red suburban]

the older diesels got much better gas mileage (6.2/6.5) and the potential for over 25mpg with a 6.2 in a 4x4 truck. power, no argument there, diesels kick ass. worth it? yes. ease of finding mechanics? all the chevy/gmc dealerships would be able to work on it, smaller shops around town you would have to ask. dont be afraid to go to a heavy duty diesel shop for engine repairs or inspections of a problem you might have (like a cat, cummins, detroit dealers/repair shops). they might be willing to work on your engine problem, just depends on their manager.

[dozerboy]

Most likely you would get a LBZ.
There is a 6 speed manual and auto, but the manual is detuned to 310HP.
Finding a stealer with a good diesel tech can be a problem, but IMO finding a good stealer tech period isn't easy. Depending where you are in Socal there are few very good diesel performance shops that I know of off hand.
Diesel can get overheated just like gassers.

[eo2159]

Will your diesel over heat No unless your pulling over 10,000 pounds over the grapevine haulin butt. Maybe not even then. And yes auto come in chevy or gmc. I just went from a 03 chevy Z71 with 5.3 and let me tell you power is night and day pulling or not and I'm running 38' tires. As far as mileage I can get 17-19 per gallon if I drive normal witch is hard, due to lots of power.

PROS...
1.better mileage
2. more initial power and torque
3. alot easier and cheaper to get even more power
4. allison trans almost bulletproof if power upgrades stay under 100 hp
5. if you go bigger lift and tires no need to regear uless over 38' tires (in my opinon)due to power
6.longevity of duramax diesel engines, tend to last twice as long as gas due to be able to make same or more power at half the RPM
7.no smog test (as of now)
8. Resale value alot better than gas
9.being able to smoke countless Ricers with a 6,000 lb truck
10.always having a grin on your face while driving


CONS.....
1.not as easy to find diesel as gas is
2.will spit some smoke if getting on the pedal
3.may get more speeding tickets pulling or not
4. uncontrolable urge to mod for more power
5. uuuhhhhhh well thats all the cons I can think of, basicly get the duramax you won't regret it.

Remember this is just my opinion

[dozerboy]

Originally Posted by eo2159

4. allison trans almost bulletproof if power upgrades stay under 100 hp

Not with the LBZ

[PerfectReign]

Thank you, everyone, for the well-written and informative replies.

I went out and test drove a 4x2 Silverado Crew Cab 2500 short bed with the 6600 and the Allison transmission. Here are my thoughts:

1. The truck idles rougher and sounds a bit harsher than the gas version at standstill. (I drove the Silverado and sierra 5.3L gas versions a few weeks ago.) Once I got going, however, the truck became both smoother and quieter than the gas versions. Go figure. At cruising speeds, the truck was noticeably quieter than the gas version.

2. The truck suspension was a bit stiffer than I’d like. I’m guessing that could be fixed aftermarket without a problem. It is obviously designed as a heavy-duty truck, hence the HD. I talked to a buddy who has a Yukon XL and he had some suspension work done. I’ll bug him later on.

3. The power was amazing! I didn’t floor it, but I noticed that the truck didn’t even flinch when I wanted it to get up and go. It just responded exactly how I needed it to. This is something I always noticed being an issue on GM trucks, including my old Jimmy. There was always a lag before the truck would lumber into the correct speed. In addition, I’d always felt the transmissions were “slow” to downshift. Not this truck. I can foresee me needing to get a radar detector for this truck. I definitely did not get the “big truck” feel driving it. Unfortunately, traffic was heavy on the freeway, so I didn’t get over 50 MPH and therefore didn’t test the sixth gear.

4. Turning and handling were exactly as I expected. Just like the gas Silverado/Sierras.

5. Starting it up was a breeze. From a cold start, the thing was ready to rumble in a few seconds. It had been sitting on the lot all day, so started from cold without a problem. (Of course, it is about 90 degrees here today.)

IOTW, I’m seriously considering the diesel over the gas version. There are plenty of shops around here where diesel is sold. I am guessing this has the 26 gallon fuel tank, which should be handy. (I seem to remember my grandfather filling up two tanks on his ‘70s –era Chevy truck.)

Again, thanks for all your help. I’ll update once I actually get the truck, which may not be until the end of the year. I’m saving up my GM Card right now. I have some construction to do around the house, and am going to charge it all to the card. That should help offset the cost of the diesel.

[K5Fury]

Diesel's have come a long way in the noise department. They will probably rattle at idle forever because of their very high compression ratio. But like you said they are pretty quiet once they get going. Also you said you didn't get up to highway speed but another beauty of the diesel is it will never downshift going up a hill----ever. Unless of course your pulling a big load.

[dozerboy]

It the suspension really bothers you don't count on much of a fix new tire, shocks, and 1/2 ton springs help but that’s it there is no real cure yet. It has a lot to do with the wheel base of the truck and the frame.

[PerfectReign]

Originally Posted by dozerboy

It the suspension really bothers you don't count on much of a fix new tire, shocks, and 1/2 ton springs help but that’s it there is no real cure yet. It has a lot to do with the wheel base of the truck and the frame.

Well, bringing the truck to a 1/2 ton range is exactly what I would want. Thanks for the input. I'm not looking to turn the truck into a car-ride, just a little less stiff.

I just got my new Motor Trend magazine today and they had a quick rundown of the '07 Silverado/Sierra lineup. In the article, they mentioned nothing about there being a diesel powerplant. Odd.

I think it wil be good to get an '06/'07 classic as the prices will be right, IMO.

[dozerboy]

From what others have said you won't get it to ride like a 1/2 ton at least with the mods I listed above.

[PerfectReign]

Originally Posted by dozerboy

From what others have said you won't get it to ride like a 1/2 ton at least with the mods I listed above.

Again, thank you. I went during lunch today and drove again the new '07 Avalanche LTZ. Nice truck! It was very smooth and "cushy" over the same road as the 2500. I'm gonna have to take my wife out and see what she thinks. Though I'm hooked onto the idea of diesel - 600 ft/lbs of torque vs. 350 ft/lbs - I'm going to have to pay attention to who will be driving with me. She used to hate my 4x4 when we went over bumps and whatnot.

Decisions, decisions...

[johndeerrm]

next time you try a 2500 check to see what the pressure in the tires is at. Chances are the dealer has it cranked up to max (80psi) based on what the door says. Lower it to 60-65 and the ride will improve.

[northface]

another thing that might help the ride is weight in the bed I got one of these for traction but it helped out the ride also

http://www.shurtrax.com/index.asp

[rockme2]

First Diesls are cool. Keep in mind that the 07 trucks are getting the DoD (4 cyl. shut down at Highway speeds and at stop lights) which will help with MPG, just not sure how much it will help. I have an 06 5.3 CC 1500 and get 19.5 on the high way with a K&N replacement air filter and a Fold-a-cover on the bed @ 70-73 keeping it under 2000RPM at all times.

[Yamsi401]

Don't think - DO!!!

[PerfectReign]

Originally Posted by Yamsi401

Don't think - DO!!!

LOL! Well...

...based on a friend's recommendation, I'm now leaning more towards the '07 Avalanche. Sigh...so many choices! If only I could get the AV with a duramax.

[dozerboy]

I wasn’t trying to talk you out of a Dmax just giving my .02, also airing down and weight don't help a lot I have run my rears as low as 45psi and have at least 500lbs. in the bed.

Originally Posted by PerfectReign

LOL! Well...

...based on a friend's recommendation, I'm now leaning more towards the '07 Avalanche. Sigh...so many choices! If only I could get the AV with a duramax.

I went through the same thing I picked a diesel for the longevity, power, and resale. I had concerns about "bugs" in the DOD on the 5.3, also water leaks, and bed size. I have no regrets I love my Dmax.

[PerfectReign]

Um, yeah - water leaks. For the what? Ten days it rains around here? :)

Seriously - valid points. I just gassed up my wife's '05 Vue today next to a guy who has an '03 Avalanche. He's got 150K miles and is happy with it. I then saw a guy with a 6.5 Suburban. He's also very happy. Go figure.

It is a tough decision. I'll have to drive the 2500 again. They're not easy to find!!

[PerfectReign]

(replying to my own post....)

I wonder what the difference between the Chevy and the GMC is?

I think a lunchtime trip to the GMC dealer is in store for tomorrow.