Diesel vs. gas engine on Chevy 2500HD

I believe you will find that a 2500HD with a 6.6L diesel or 8.1L gasoline with Allison transmissions have considerably more towing capacity, especially 5th wheel/goose neck, than any 6L gasoline engine and transmission combination. Travel trailer tow capacity may be about the same due to hitch limitations.

Yes, but it will probably go twice as many miles before it needs any repairs. The injectors on my '01 Duramax diesel had an initial 100,000 warranty that GM extended to 200,000 miles.

Not when towing a small light trailer like you are. When driving solo diesels will get much better mileage than the big block gasoline engines, but may not get much better mileage than the small gasoline engines like the

6L.

Ron

Well, but the 8.1 has a really bad fuel economy, right?

That's a good point.

Did you buy extended warranty on them?

Yea. You see, I have a 5.9 liter engine on my Dodge, and it is perfectly adequate for what I need. It is the rest of the drivetrain that gives me issues. Engine power is not the issue for me currently. I just want to have a solid transmission, transfer case, front and rear end etc.

i

Yes do not compare a 6.0 gas motor to a 6.6 Dmax in towing power regardless of paper HP rating. If you are serious about towing abilty get a 8.1 or Dmax and you will not be disappointed. ALso when towing the 8.1 will likely get better MPG than 6.0 gas will doing same job. I have driven new trucks with a 8.1 and a 4.10 with a 6 speed and it is a sweet combo and fun to drive too.

----------------- TheSnoMan.com

Not that bad and no worse towing. If truck is left stock tires and lift wise 16 or better higway should be quite doable with 6 sp ally because when I drove one for a while and the MPG computer showed 15 to

15.5 at 65 on a new truck not even broke in. That new ally is a better match to 8.1 than Dmax in some ways. You drive a 8.1 with 6sp ally and a 4.10 and you will be spoiled as it gets with the program right now. The Dmax has more power on paper for pulling but in the realworld seat of the pants the 8.1 is more responsive to daily driving throttle inputs because of its wider usable RPM range and no boost to build. I do not look for diesel to ever be cheaper than gas again and I expect it to exceed gas prices by a dollar of more this winter(like it did here last winter) so figure that in you banalnce sheet too.

----------------- TheSnoMan.com

Snoman, that's very nice, and upgrade to 8,8.1 liter engine is not that expensive (though allison tranny is).

i

Yes the Ally is about 1100 more than the 4L80 that comes with 6.0. It would add about 2 k or less to price of truck for 8.1 and Ally. Also for what it is worth you can get the Ally with 6.0 to if you order it. This has been possible since 2006 on Chevies but it is not well known. The reason for this GM was supposed to roll out a V10 in 07 to replace

8.1 but it got shelved because of gas prices last year and the V10 is based on 6.0 block with two cylinders added so they had tooled up for its bellhousing (it is different than Dnmax and 8.1 which share bolt patterns) so as a result of this you can get a Ally with a 6.0. You have to drive 8.1 because it is the last of the really powerfull gas motors for HD trucks. When it is gone it will be the end of a era as the block it is based on has been around since the mid 60's so you are kinda buying a piece of history. The only ther engine that served longer was the SB chevy which was laid to rest around 2002 after nearly 50 years of service. (still availble is crate motors though)

----------------- TheSnoMan.com

If you buy the 8.1L, it will eat gas all the time towing or not. So the 95% of the time you're using the truck and not towing you'll pay for it. Just post on this list for real world 8.1 gas mileage figures.

Al

I drive an '02 8.1L w/ 4.10 in a 2500HD crew long box and love it for the towing of our 32' fifth-wheel. You are correct about the no worse when towing, but 16 MPGs????? What dream? :-) Mine is a 4x4 and the best I've ever done is just at 12 MPG w/ only a bed full of fishing gear and one other passenger on a long highway trip at an average of 68 MPH. I know of an ext. cab 2x4 that has done just a shade over 12 MPG w/ the same 8.1L and 4.10. My usual MPG is an average of 9.5 MPG hwy/city combined. Good truck, but not pocket friendly, but then again neither is diesel at $ .60+ more per gallon right now. Then again if you want to play, you have to be willing to pay! :-)

Not as much as you suggest because if you are comparing it with a Dmax the fuel cost less and has for some time and it will likey be a lot less this winter and every winter too. A friend of mine bought a Dmax about a year ago hoping to same money over his current gas work truck. Well is did not work out as planned because diesel fuel shot up right after he bought it and when he factored in operating cost and cost of Dmax he lost money. He started out looking for a 8.1 but could not find one and he is thinking of trading it in on a 8.1 now because he will be the first to admit that even after owning a Dmax for over a year now that when he drives a 8.1 it brings a smile to his face when he steps on the gas pedal because that engine is VERY willing and reminds him of the old days when gas motors had some serious power as we are both old enough to well remember them. Nail them both at a standstill from a idle and the 8.1 will be long gone while Dmax is still spooling up and shifting because of its limited RPM range (that is after the 8.1 gets into second gear and hooks up solid because tire spin can be a real issue on 8.1 in first gear. With 4.10' in 6th gear it is only turning about 2100 at 70 MPH and it will step right out in

6th even that speed if you goose it a bit. Kick it down and it really takes off. Any trailer you can tow with a Dmax you can tow with a 8.1. It is simply a incredible tow motor too. Sure in may use a bit more fuel but it will never leave you wanting for power when you need it and it is very quiet too. (if I was not putting two kids through college I would buy a new 8.1 for myself before they are gone. (they were not availble in 2000 when I bought my last truck)

----------------- TheSnoMan.com

Never did a MPG check with one with 5 speed but the few I have driven with the new 6th speed with double OD do a lot better because if you whatch MPG meter there is a 2 to 3 MPG drop from 6th gear cruise at 65 when you use 5th which was top ratio in older 5sp model. I had my reservations about a double OD tranny when I heard about it but it a match made in heaven behind a 8.1 with 4.10 gears. Also when going for max MPG keep tires hard (60PSI or better) and use a smooth narrow tread as cleated tires use more fuel and the 8.1 will also do better if you feed it 89 octane of better especail in hot weather or towing. Try it sometimes.

----------------- TheSnoMan.com

I've wondered about the 6 speed tranny as well, but have not driven one. It would just be nice to be able to lock OD out on mine like my brother can on his '03. Once in a while on longer climbs, as in the mountains of TN and NC, you have to play the accelerator to stay in fourth and third is just to low most of the time. That is some serious MPG jump if it really works out over time. I do keep my tires up around 65 and 70, but burn 87. I've tried 89 a few times while towing and saw only a very slight increase, not enough to make it worth while. Oh well, interesting just the same. It still comes back to the fact that if you are pinching pennies on fuel, the bigger trucks are not your thing. :-)

No aurguement there but as you know firsy hand that 8.1 is a sweet engine and very likely the last of the old Chevy "Rat" motors.

----------------- TheSnoMan.com