Advice on choosing and Older Suburban DIesel?

hertfordnc wrote:
So the consensus is that they don't get great MPG (empty) and the engines are not that great, compared to Cummins or the Ford 7.3?

Was Duramax the beginning of Chevy being a real player?

I'm still curious though. I'm also interested in biodiesl and/or WVO but I don't want a $20,000 truck that will mostly sit in the yard between road trips.

I am close to retirement but with two little boys in the house (it keeps me young) Ford and Dodge did not make many crew cabs before the late 90's so the prices are high. The diesel burbs have been around since Reagan.

You are correct between the comparison between the 7.3 and the Cummins. The Cummins was a way better engine and the old non Powerstroke 7.3 was a slightly better engine.

You are not correct about the fuel mileage. The 6.5 is really fuel efficient. With 21.5 to 1 compression ratio they are really efficient. It just won't get 20+ "average" in a burb like you want. I don't know anything that will in that box. The burb is big, heavy and about as aerodynamic as a piece of plywood.

Well, I take that back. The 6.2 N/A non turbo will get 20+ in a burb but if you put anything on the tail you will have turtles pass you on hills. On the flats you will be fine but in the hills it will get ugly.

One other thing. If you are interested in alternative fuels. As soon as I get a few more things squared away I will start to burn black fuel in my 6.5. I highly recommend that if you want to do this or burn bio or grease or whatever you get a 93 like mine. 93's were all mechanical injection and you can burn about anything you want in them. The 94's on up had electronic injection and they were WAY more picky on what goes through their pumps.

One thing you might think about is if you start to burn black fuel or grease you might get up to your 20+ MPG because black fuel or grease has more energy than #2. Just another plus when driving older diesels.

BTW, yes, the Dmax was GM's first real "good" diesel that they put in their pickups.

Good luck with you quest. :)

So the consensus is that they don't get great MPG (empty) and the engines are not that great, compared to Cummins or the Ford 7.3?

Was Duramax the beginning of Chevy being a real player?

I'm still curious though. I'm also interested in biodiesl and/or WVO but I don't want a $20,000 truck that will mostly sit in the yard between road trips.

I am close to retirement but with two little boys in the house (it keeps me young) Ford and Dodge did not make many crew cabs before the late 90's so the prices are high. The diesel burbs have been around since Reagan.

hertfordnc wrote:
In my research on other diesel trucks under $8000 the Diesel Burbs from the 90's come up a lot, and cheaper than comparable Fords & Dodges.

The selling point for diesels of that era was the ability to burn the much cheaper diesel fuel. Since diesel costs as much or more than gas they kind of lose their charm. I think you'd be happier with a 350 or 454 Suburban provided the axle ratio was right for towing.

Have you given any consideration to a 7.3 diesel Excursion? They are hard to find but they are out there. 2000-2003.25 MY had the 7.3 which many agree is a very good motor.

My 00 and 02 diesel Excursion both get good fuel mileage and both have original motors and trannies. 00 has 265K miles and 02 has 292K miles. I would drive either one anywhere.

44 gallon fuel tank, 3/4 ton based, seating for 7-9, solid Dana front axle, locking front hubs, and decent towing capabilities.

Word of caution, 6.0 diesel Excursions...

Seen a few 2000 Excursions for sale locally with the 5.9 Cummins conversion. One for sale locally is set up to run on veggie oil.

Find a 2wd Burb with a bad engine/trans and replace with a Cummins. You will have an awesome towing machine and great mileage running solo. Look for a 98 12Valve and 5 speed stick. Best of them all.

I get 21-23 mpg on a 35 mile commute running 60-70 with my new 98 12V 5sp 2wd RAM quad cab. Hand calc over several tanks.

hertfordnc wrote:
I came very close to buying a Dodge 3500 Cummins this week but the family didn't love it so I let it go. In my research on other diesel trucks under $8000 the Diesel Burbs from the 90's come up a lot, and cheaper than comparable Fords & Dodges.

In further research i find people on other forums saying there are some bad ones to avoid. I know i don't want a 700R4.

So, I would be grateful for a summary of what to look for and whether or not folks here think one of these would be a good choice.

THe goal is to have a 20+ mpg daily driver that can comfortably pull my 6000 lb trailer up the mountains (East Coast mountains)

Thanks

The 700R4 never came in a 6.5 turbo. The 6.2 N/A, yep, but not the 6.5.

I own a 6.5 and really like it. I even like driving the 6.5 truck better than my LBZ Dmax.

That being said. The 6.5 has some common problems.

#1. GM thought cast iron was gold in the day and got cheap on the pour. This made them prone to cracking.

#2. A super common problem is with the PMD. No real big deal on this one because the aftermarket makes a real nice one with no problems.

#3. They had some cracking problems with the blocks in the late 90's.(2 years I think? 97 and 98 IIRC?) Again, not many were affected but it did happen.

#4. With no intercooler and the power they put out, they tended to get hot in hot weather. Again, this was pretty much fixed with duel thermostats and a better pump in later models.

All that being said most of the problems show up when you push them real hard in hot weather. They were fine for light duty work and that is what they were designed for.

You won't get 20+ MPG in a burb. 18 is about it with a burb. Trucks got better mileage than burbs and my gets 19. It's no speed demon with only 200HP. But it does get the job done with my 7K TT and gets 12 MPG doing it.

I still tow with mine and it runs great at 175K. I did update the head gaskets and put ARP studs in the block and a new style aluminum radiator.

All in all the Cummins is light years ahead of the 6.5 as far as dependability and robustness of design. Plus with the Cummins you can turn them up to get good power out of them. If you do that with the 6.5 you can start breaking blocks and heads.

Bottom line is, some people like them and some hate them. I can't tell you what to do but I like mine.

I think the Cummins is by far the better engine, but as you say you have to like the truck too. Cummins only comes in a truck, not a big wagon like the Suburban. Diesel engines in the 1990's were very underpowered compared to today, and the 6.5 was the worst of the lot, under 200 hp in an 8,000 lb truck. Decent torque. Several known issues like crank's failing, fuel injector modules failing. AM General is still putting them in military hummers as far as I know.

Brian

By the time the 90s rolled in the 700r4s were history. I'm not sure they ever put them behind the 6.5s anyway. Early was th400 and then the 4l80e. But I'm getting old and may not remember properly. The Cummins would be a far better choice.