GM 8.0 liter's Who has them?

**Blown25thT/A** · 02-24-2006, 05:09 PM

As the title says, Who has them? Any problems, how many miles do ya'll have on them?

I'm thinking about getting one. Any insight one them would be helpful.

Thanks

**98bpmta** · 02-26-2006, 05:26 AM

i had the 8.1 in a 2001 dulley. with the allison trans.

i pulled a 2 car trailer with it [ 2 f-bodys] IT LOVES GAS!!!

best pulling truck i ever owned,

got about 8-10 mpg loaded

, 10-14 unloaded.
it's built just like the LS1 but big block. think it's 370 hp and like 500 tq ???

we towed 4 TAs to dayton oh for the ta nat's the other 2 were a dodge and a trailer and a ford with a trailer
i would run off and leave them, and i had 2 cars and the 2car trailer alone wighted about 3500

ps the dulley had a 38 gal gas tank,

**Blown25thT/A** · 02-26-2006, 06:46 AM

How many miles do you have on yours?

**98bpmta** · 02-26-2006, 08:21 AM

about 60,000 never used no oil unlike the 454ci that allways used it ever new. in my 98 gmc.

i think the way to go is the diesel but at 30-50 cent a gal more than gas i have to think about it. duermax or cummins.

i here some of the diesels are geting 15-20 mpg , but the price of fuel.

i drive a 550hp cummins at work in a kenworth t-600 and it will hual the load.

**Blown25thT/A** · 02-26-2006, 09:05 AM

I found a good deal on a '01 dulley with the 8.1 in it with 70,xxx miles for 12,500. Thats why I was asking.

**ss~zoso~ss** · 02-27-2006, 03:35 AM

gas or diesel?

**mdh100** · 02-27-2006, 11:22 PM

I'd rather have diesel. With basic maintenance they're a longer lasting engine and get better gas mileage than a comparable gas engine. My cousin's construction company has a few cummins and a few navistar trucks. Both get about the same gas mileage...12-14 loaded and 19-24 unloaded. I'd prolly go with whichever was the better price...either one will have transmission problems if you use it strictly as a tow rig..although I think ford's may be a little stronger.

**timowen1** · 03-04-2006, 09:07 AM

This is my second 8.1. They are unbelievable trucks. I calculated a little before buying my second 8.1 and decided not to go with the D-Max. they are the ultimate but think about this. They are $4K more than the 8.1. With D-fuel costing on average .30 more per gallon than gas and only about 7 mpg better than gas it will never pay for itself unless you keep it about 200,000 miles. Who does that??? I know some guys do. IMO the only thing they really have going for them is they are a little more maintance free. Power... more but not worth $4k. I pull a 26 foot enclosed trailer with a 3,800 lb. T/A loaded with all excessories and scooter I figure the trailer weighs about 9,500lbs. I travel with two friends,one has a 28' trailer with the same cargo and pulls with a 2001 Ford Super Duty power stroke. He can't even begin to keep up with me. The other guy has a 26 footer with the same cargo and pull with a 2004 Ford Super Duty with the newer Power Stroke and I can almost out run him. If I had the D-Max I could. But $4K is a lot of money for bragging rights. I put 87K on my first and have 68K on my 2003 Sierra. I will no doubt keep this one until it has 200K miles on it.

**Blown25thT/A** · 03-04-2006, 03:17 PM

Thanks for the input everyone. I think I have made up my mind.

**RSSS** · 03-07-2006, 07:24 PM

Mine, a 02 2500 4door 4x4, gets 9 mpg unloaded and as low as 4 loaded. It runs awsome, but burns a quart of oil for every 900mi. It has 155xxx miles and never has never been in the shop. (for motor or tranny work). Its used the oil since new and you never see any smoke.

**timowen1** · 03-08-2006, 02:58 AM

Originally Posted by RSSS

Mine, a 02 2500 4door 4x4, gets 9 mpg unloaded and as low as 4 loaded. It runs awsome, but burns a quart of oil for every 900mi. It has 155xxx miles and never has never been in the shop. (for motor or tranny work). Its used the oil since new and you never see any smoke.

Sounds like I have the same truck. 2500 HD 4x4 crew cab. I hear horror stories about guys who get low fuel economy and burn, or use, oil. Going by the DIC in my truck I get on average 12.6 MPG. I drive highway/city at about 50/50. Oil consumption is about 1 quart every 1,500 miles. What I did for mileage, and I see my money was well spent. Tonneau cover, K&N filter and a custom computer tune by Jesse Bubb of Warsaw, Indiana. The Tonneau was about $200 the K&N was $50 and Jesse only charged me $75 for the tune, which made a big difference in all around power and pulling performance. My open road mileage is about 15.5 mpg and pulling just under 10,000lbs I get 9 mpg. I am interested in seeing what I get this season, I put a big ass set of tires on the beast this past winter. I now have just under 70,000 miles on my truck.

**timowen1** · 03-08-2006, 02:59 AM

Originally Posted by Blown25thT/A

Thanks for the input everyone. I think I have made up my mind.

So tell us what is it going to be??? Ain't this a great forum, LSI f-body cars and 8.1 trucks. It don't get much better.

**RSSS** · 03-08-2006, 04:23 PM

What gears do you have, Tim? I'm running 4:10 with 285's The truck makes awsome power, watch it on wet pavement! It's a gas guzzler I've never got more than 220 miles a tank! Mabye a tune is in order. Do you have any contact info for the computer tune guy?

**timowen1** · 03-08-2006, 06:59 PM

Originally Posted by RSSS

What gears do you have, Tim? I'm running 4:10 with 285's The truck makes awsome power, watch it on wet pavement! It's a gas guzzler I've never got more than 220 miles a tank! Mabye a tune is in order. Do you have any contact info for the computer tune guy?

I am running 3:73 gears. I rechecked my MPG average tonight for the first time in two months and it dropped to 11.5. I had BG Goodrich all terrain 285's put on the truck about two months ago. I think the wider tires dropped my mileage a bit. But still not bad for what I got. I thought about the 4:10's a year ago. Found a local auto shop that will put them in for about $600 parts and labor, that's both front and rear. I didn't think I wanted to sacrifice that much gas mileage though. If you talk to Jesse tell him my name, Tim Owen, and I was the person he met at Sears in Fort Wayne about a year ago, and he tuned my truck in the parking lot in front of the key shop at Sears. He also did a new pcm for my 2001 Trans Am. Now that really made a difference.He did my truck for $75 and cloned my original T/A pcm into one of his then custom tuned it. This allowed me to keep my original all original and put it on a shelf then run the custom tuned pcm. $140 !! What a deal. That was the pcm plus tuning. He is a great guy who knows what he is doing. He will promise a 2 mpg increase or he will send you your money back and you keep the custom tune, as long as the truck runs o.k. Also give free lifetime upgrades if you change something that would require re-tuning, like a cam. You just pay for return shipping.

[email protected]
cell 5745279567
home 5742673630

**Blown25thT/A** · 03-09-2006, 11:27 AM

I'm going with the 8.1. My brother-in-law is getting the Duramax. So we'll get a good side by side comparison.

Thanks ya'll for all the imput.

**Wyoming T/A** · 03-30-2006, 06:48 PM

had a 2001 hd 3/4 4wd with a allison ,great truck averaged 14.3 to 15.5 hiway but you got to drive it easy to get that 4.10 posi,about 10.8 to 11.2 pulling 4500#,got a new 06 LBZ with allison.17.4 first tank and improving a little at a time. 360 hp/650# torque,awesome truck ,will just about pull toung out of trailer,ck. out my grandsons new ride .all orig.1966 GMC 3/4 90k .has a1 1/2 years to go thru it mite do a lt1 swap, anybody ever do one give some pointers,never done one at our shop..i pull 14000# up 10 to 13 %.grade to ride horses 8.1 is 15 mph slower and almost twice the fuel//

The Rookie · 03-30-2006, 06:52 PM

My 04 Duramax is a haus!! Pulls my 4000 lb boat like its not even there! I get about 18 on the highway with 285-75-16 BFG A/T's. about 15 in the city. Before the bigger tires I was getting about 21 highway and 17 or so in the city. My company pays for all my diesel fuel..

**Wyoming T/A** · 03-30-2006, 06:56 PM

Originally Posted by Blown25thT/A

I'm going with the 8.1. My brother-in-law is getting the Duramax. So we'll get a good side by side comparison.

Thanks ya'll for all the imput.

dont do to much comparing , we haul trailers all time and drove my 8.1 50000 miles and my lbz will destroy my 8.1 and i really liked my 8.1,my lbz has more torque in 6th gear ;allison 1000; than my 8.1 had in 4th ;allison ; same ratios in trans;

**Corona-Extra** · 03-30-2006, 07:49 PM

Originally Posted by The Rookie

My 04 Duramax is a haus!! Pulls my 4000 lb boat like its not even there! I get about 18 on the highway with 285-75-16 BFG A/T's. about 15 in the city. Before the bigger tires I was getting about 21 highway and 17 or so in the city. My company pays for all my diesel fuel..

Just curious. Do you have the Hypertech programmer? My dad has a 2005 2500 Duramx with the programmer. He’s getting 22ish on the highway and about 18ish in the city. If you’re pulling boats and shit, that think would be right for you.