# Truck Fever 2500hd 8.1l Thoughts?



## jgerni

I've had the truck fever for over 6 months now and its getting painful.

I've got my eye on a Chevy K2500HD crew cab with the 8.1L, Allison automatic tranny and 3.73 gears. What is you experience with the 8.1L?

Would love the diesel but don't have the extra $5000 and since the truck won't get but 5000 to 8000 miles on it per year and only 1/2 of them towing I don't think its justifiable. This vehicle will not be a daily driver and will sit in my garage until camping or hauling the garbage or the occasional bed of mulch

Thoughts of the 8.1L towing besides its love of dyno juice?

Also, what are your experience with MPG with this engine?


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## mswalt

jgerni,

I have a 2003 Chevrolet Suburban 2500 with the 8.1 L vortec engine. I've had it for about 8 months now and towed the trailer twice with it so far; once, a 250-mile excursion to New Branfels; the other, 90 miles to Brownwood State Park. My previous tow vehicle was a 2001 Chevrolet Suburban 1500 with the 5.3 L.

There is no comparison! The 2500 pulls the TT (I have a 26RS) like there's nothing behind the car. The 1500 struggled up the slightest grade.

Our 2500 is an everyday vehicle (the DW;s) and she loves it. We've taken it on a couple of trips without the trailer, too. Love the ride.

Gas mileage is another story. Haven't checked the wife's mileage but mine's about 13 in the city or on the road; either one doesn't make any difference in _my_ mileage. Towing, drop that down to about 9, I think.

The way I figure, though, is that for the increased safety I feel when towing, the mileage doesn't bother me. Anyway, if I couldn't afford the gas, I couldn't afford the Outback. IMHO.

My recommendation is to go for it.

Mark


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## wapiti13

I have the 8.1 with the 4.10 rear end and Allison Transmission. Tows our Outback like a dream whether on a flat highway or on hills, great acceleration! Mileage is another story as I only get 8.5 to 9.5 mpg while towing. Still it's the nicest truck I've ever owned.


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## our2girls

A Dodge 2500 HEMI will have no problems towing , and get better mileage.
5.7 L vs. 8.1 L, I'm not a rocket scientist by any means, but the Dodge will handle a 26 footer no problem, with comparable power.

I'm towing with a 4.7 Magnum....the little engine that can! (25 RS-S).

Mike


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## johnp

Hi 
I have the 8.1 and love it. I don't need to drive daily so I don't care about mileage but it gets about 10.5 towing and 12 without. It towed my 26RS with no effort at all. Now its time to see how it does with the 27RSDS and 33" tires. Its the second best tow setup out there next to the Duramax/Allision. Just my opinion.

John


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## jzero

*No replacement for displacement!* Forget the "Hemi"!








If your just using it for towing (an absolute dream set up) then get it. I've been explaining to my friends that are die hard diesel fans, that you can buy a lot of gas for the $5000.00 upgrade fee. And thats the difference in mpg only, that you're making up. You'll own it 15 years before you'll even break even. Then there's the 100.00 oil changes and fuel filters with the diesels.

Good luck.


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## wingnut

Hi,

I think you are on the right track. Right now the GM product line has the best transmission on the market for towing. I mean the Allison. They build transmissionis used in trucks of all shapes and sizes. I sell for a big truck company and the Allison is the only fuly automatic on the market now. the 1000 series is the baby brother to the transmissons I spec on a daily basis to be used in anything from a highway tractor to a fire truck. As far as the engine, it may be more cost effectve to go with the 8.1 instead of the deisel, two reasons for this. One it is less up front cost. Two with the new EPA standards that will be going into effect in 2007, deisel will have to be made to a new low sulfer standard. According to the engine manufactors that I deal with on a daily basis, this will increase the cost of deisel buy 30 to 60 cents per gallon. OUCH any way you look at it.









Todd


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## aplvlykat

Oh, I got the fever also, can't shake it. The last 5 autos I have owned have been GM excect for a 1996 ford ranger, great lttle truck. I put close to 185,000 on it commuting to work. So I have been looking at the ford F250 with the V10 in it. I know it doesn't get the best gas milage but it will out pull my Tahoe any day of the week. I am tired of struggling up hills and am afraid I am ruining the Tahoe in the process. Does anyone know if there are any problems with the 2005 F 250 with a V10. Kirk


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## bt996sb

I work at the plant that builds the F250 and the Triton V-10 has a great record. It is a very good truck. No problem out of the motor at all.


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## jgerni

The funny thing is that I only get 9 - 10mpg towing and about 15 mixed driving with our 5.3L Suburban. Itâ€™s quite amazing that the 8.1L can get similar MPG as the 5.3L. I've always heard that the big blocks get about the same as small blocks when towing and some times better depending on how heavy the load.

Isn't the Chevy 8.1L the only true "Big Block"? Isn't the Ford V10 just the 5.4L with 2 cylinders added?


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## Morrowmd

One reason the mpg is similiar may be because you can tow in OD. My father in law has the 8.1 & Allison tranny setup and pulls a 9000# 5er. He says the engine is great but the tranny is better- never get that "lugging" you usually get pulling in OD.


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## Fire44

I am towing a 27RSDS with a 2000 Suburban 4x4 with a 5.3L/3.73 and just got back from a 1100 mile one way trip. The truck did good pulling and we got around 10-11 mpg running about 60 mph. We had to push it hard one day to make get to a campground and it dropped to about 7.5 mpg at 70-75 mph.







I don't see how a 8.1 L would be able to do any worst.

A 3/4 ton with a 8.1 liter would pull my trailer much better but this vehicle is my daily driver....so the 11-12 mpg not pulling would not be good for me. I get about 15-16 driving back and fore to work.

The 8.1 L is a great motor as is the 6.6 Duramax but what makes them work so good is the Allision transmission. IMHO and I have been selling GM vehicles for about 19 years. The Ford V-10 does make more hp and about the same torque as the 8.1 but they don't have the Allision tranny.

Gary


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## jgerni

Fire44 we currently have the Suburban like you and it does an adequate job in most situations but it does feel like it is working. We once got climbing those hills in the Smokey Mountains and got 7 â€" 8mpg as well. Most of the time though we can get around 10 though.

I have to replace my current truck Dodge Dakota so I figured I would get something that I could tow a 5th wheel which may be in our future in the next couple of years.

Since the truck would not be a daily driver and would only get 5K to 8K miles per year on it I thought the 8.1 would be the most economical way to go.

Doesnâ€™t the V10 in the Ford need to rev pretty high to get to its Max torque just like a small block?


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## jallen58

I have a friend with the v10 and he tinks its a dog unless you really mash the pedal and wath the gas guage drop. I just traded my 99 burb 5.7L for an 03 silverado 1500HD 6.0L and it pulls my 28BHS like its not there. I chose the 1500HD over the 2500HD because it's my daily driver. If this wont be your daily driver you shoul;d go for it. The only downside to the 1500HD is no allison but it does hav a heavy duty transmission Different than the standard 1500. The 1500HD also hase the same weigth ratings as a standard 2500. So fro the small comprimse i got the 1500HD and love it.

Jim


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## Fire44

Both the GM and the Ford have roughly 450 lbft of torque at 3200-3300 rpm. The Ford does have a little bit more horsepower but it is at a higher RPM. I am not going to say anything bad about the Ford V-10, it is a very good engine, but I just keep thinking about the tune-up's (more plugs, more plug wires). I know that GM is using 100,000 mile plugs, I don't know if Ford is or not. I think it is just a matter of your prefference. I have always been a GM person, (my father just retired from the dealership that I work at in Oct. after 48 years in truck sales) so I grew up in a Chevrolet and would like to be carried out in a Chevrolet.

But all of the brands make a good product, GM, Ford, Dodge, Nissan and the rest....if they didn't they wouldn't be in bussiness anymore.

Gary


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## jgerni

I've looked at all three and guess I like the Chevy crew cab since it looks almost identical to our Burb.

jallen58 I've also looked at a used 1500HD that was in very good shape and probably would have bought it if it didn't have the 3.73 gear in it. The 3.73 limits the 1500HD to a tow rating of like 8300lbs compared to 10300 with the 4.10. In some cases noted the 1500HD has more hauling capacity than the 2500HD with the D/A combo due to its lighter weight.

My truck won't/can't be my daily driver since I have a 100 miles per day commute. Could you imagine driving the 8.1L 100 miles per day 5 days a week. Gas here is 2.25 per gallon so if the truck got 12mpg that would be $400.00 in fuel per month


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## mswalt

jgerni,

Have to agree with that long of a commute. I commuted about 80 miles one-way for almost 7 years. What a drag! My little S10 did OK on mileage but 3 hours per day on the road was toooooooo much.









I feel for you.

Good luck on your choice.

Mark


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## jgerni

mswalt, i second that on the commute.







Fortunately, my commute is not in congestion and can be done in 50 minutes one way 95% hwy. I currently use a VW Jetta diesel that gets 50+mpg







. There are many people in big cities that live 15 miles from work that take longer.

Itâ€™s so funny seeing the ultimate fuel efficient car (Jetta TDI) next to the ultimate gas loving vehicle (Suburban) in my garage. I do know that I wouldnâ€™t want to be in an accident against the Burb though.


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## Fire44

I really feel for you guys...I have almost a 2.5 mile commute and it takes me a whole 7-10 mins. I don't think I could drive 100 miles to get to work. I would have too much time to think of some reason not to go.


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## HootBob

I could not commute 80 -100 miles for work
That would drive me crazy 
I'm glad work is exactly 2 miles up the road from my house about 5 mins
Nice if I want to come for lunch,I can








Don


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## mswalt

I agree. I *USED* to commute. Now I take a leisurely drive, about 7-10 minutes just down the road a piece from the house. It is sooooooooooooooo much nicer.









Mark


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## DANJOGAVINMO

Although the discussion is mostly about V10's, I thought it worth a clarification that some of ford's triton small blocks actually produce good torque at lower rpm. For example, my 2002 5.4L produces 350ftlb at 2500 rpm. This model of the engine has only the 2 valves per cylinder.

It looks like newer 3valve per cylinder heads moves peak torque up a bit (365ftlb at 3750rpm) for the 5.4L. 2005 Superduty V10 shows to have 455ftlb at 3250rpm (3valve per cylinder also).

Of course, the manufacturers rarely publish RPM vs. Torque/HP curves anymore, so it is hard to tell exactly at what RPM you start getting respectable torque.

F150.net has some good spec web pages BTW:
http://www.fordf150.net/specs/

Grumpy


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## z-family




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## jgerni

Its really not by choice that I am commuting this far believe me I would rather not. I moved withing 15 minutes of work one time and after 4 years ended up getting laid off. Since being laid off I was only able to find work (work that would pay anything that is) that was 50min away. Within that 4 years we started a family and had put down many roots in the community so moving wasn't an option since a 50 minute drive one way resonable commute considering the alternatives.

Z-family:
I doubt you will see a huge difference in fuel economy from the 5.7 to the 6.0. Anyway you slice it it is not going to be good and any little difference won't be enough for you to base you decision on MPG.


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## jallen58

z-family the early 6.0L had a problem with piston slap the one you are looking at may or maynot have had this problem as not all of them did. If it did it may have been fixed by gm they take each case seperate and deside if it is bad enough to fix. Ask the owner if the engine had this problem. Gm says it is no problem however i believe they are fixing some. As for fuel milage not much differance at all the 6.0L seems a little better towing because it doesn't have to work as hard.
I love mine much better TV than the 99 burb.
From Pages 90-91 of the March/April '03 issue of TruckTrend

We've finally gotten an answer on the cold-start piston knock involving 4.8, 5.3 and 6.0-liter V8's in '99 to '02 GM cars and trucks. General Motors has previously released a Technical Service Bulletin explaining the condition that occurs after approximately 12,000 miles and a normal accumulation of carbon above the top piston ring.

I spoke with Sam Winegarden, GM program manager and chief engineer for small- and big-block engines. Sam explains that following extensive testing, General Motors is confident the start-up noise will have no adverse effect on performance or durability of the engines involved.

As opposed to the larger pistons of earlier design engines, today's technical refinement requires the use of smaller pistons to reduce weight and reciprocating mass in order to aid in efficiency and durability. This reduction in size also reduces the stability of the piston in the cylinder bore, which can promote piston noise.

Preliminary testing on these engines showed no sign of a problem, but, as in many other situations, the symptoms came to the surface after the vehicles were subject to normal driving conditions.

The manufacturer's stand on the issue is that it doesn't warrant a service bulletin or recall promoting a repair. We were also assured the problem has been corrected on the '03-model line with a piston-design modification along with the addition of a polymer coating.

My response was from the viewpoint of a consumer who purchased a brand-new vehicle that developed a notable engine knock before the first major service. The complaint was not only about the annoyance of the condition, but also the effect on resale and depreciation.

The answer was that General Motors would be dealing with the consumer on a case-by-case basis, and complaints have been resolved by means of warranty extension and parts replacement.

The owners of involved vehicles exhibiting the cold-start piston knock should have the service manager of the GM dealership, which has been evaluating the noise, contact the manufacturer's zone representative. Hopefully you can come to satisfactory terms.

Piston Slap

Jim


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## cookie9933

Fire44 said:


> Both the GM and the Ford have roughly 450 lbft of torque at 3200-3300 rpm. The Ford does have a little bit more horsepower but it is at a higher RPM. I am not going to say anything bad about the Ford V-10, it is a very good engine, but I just keep thinking about the tune-up's (more plugs, more plug wires). I know that GM is using 100,000 mile plugs, I don't know if Ford is or not. I think it is just a matter of your prefference. I have always been a GM person, (my father just retired from the dealership that I work at in Oct. after 48 years in truck sales) so I grew up in a Chevrolet and would like to be carried out in a Chevrolet.
> 
> But all of the brands make a good product, GM, Ford, Dodge, Nissan and the rest....if they didn't they wouldn't be in bussiness anymore.
> 
> Gary
> [snapback]31114[/snapback]​


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## jgerni

Well, I finally took delivery of my new to me 2002 Chevy 2500HD Crew cab 4x4 8.1 Allison auto and 36,000 miles.







After looking around locally I took a leap of faith and purchased it on Ebay for many thousands $ less than local trucks and looks better too. Actually I got it at trade in value.

After driving this truck for several days all I can say is wow. You can just feel the power and torque of this beast and the smooth shifting of the Allison. I was very plesantly supprised when I turned 15.8mpg, empty of course in a mostly hwy enviroment at 60 - 65mph during a 150 mile trip home from picking up the truck. Heck our Suburban only got 17.5 on the same trip.

Now I can't wait to hook up our Outback to this truck to see how it tows. I doubt I will even know the 25RSS is even outback.


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## johnp

Welcome to the wonderful world of big blocks







just look in the rearveiw mirror every now and then to remind yourself the trailer is back there









Enjoy









John


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## borntorv

Congrats jgerni,

So when's the maiden voyage for the new TV? I think you've got the ultimate gasser set up with the 8.1/Allison. Have fun and enjoy the power!!


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## wingnut

Igerny congrats on the new 2U truck! Keep us informed of how it does. Don't pull the tongue off the trailer with all that power.


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## hatcityhosehauler

Wow, 15+ on the highway, my 5.3 doesn't get much better than that, and averages 12 around town. Let me know what your around town numbers are, and it just might seal the book on a 8.1 for me too!

Tim


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## jgerni

This truck has the 3.73 gears and I was making a conscious effort to be easy on the throttle to turn 15.8mpg number. I donâ€™t expect to get that kind of MPG often. Iâ€™ve noticed on this last tank that it will be quite a bit less around town and Iâ€™ve also found how much of a hoot it is to drive.









One thing I canâ€™t understand is how Chevy can put a 26gal fuel tank on the 2500HDs with the short bed. Makes no since to me at all. Heck our Suburban with the 5.3L has a 30+ gallon tank.


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