gas vs diesel

Big Al · September 12, 2006

Is anyone else out there worried about diesel prices? In my area they are consistently 50 cents per gallon more that regular unleaded. I've been waiting for the new 2007 Sierra 2500HD to come out and always thought that the Duramax with Allison was the way to go. I don't pull a lot, but my Denali struggles with any load over 6000 due to the limitations of the transmission and rear diff gearing. Now I'm starting to wonder is the diesel is the way to go. Like everyone I want 20 mpg and plenty of power. Will GM put the new 6.2L gas engine with the Allison or a revised 8.1L? Will these have DOD and be capable of 16 or 17 mpg? If so, would that be a better choice for someone like me that doesn't pull heavy loads all of the time? The mpg difference should be offset by the cost of diesel, which is predicted to rise another 10% with the new 2007 low sulfur requirement. Any thoughts?

GMSea97 · September 12, 2006

its hard to beat the stump pulling torq of a diesel, put paying 50 cents more per gallon is a tuff call. If you don't pull on a regular bases I would say a gas engine, just for the fact that the fuel is cheaper and the power isn't as greatly needed in your case.

Boondox · September 12, 2006

Big Al -- I had to make the same choice and ended up with a 6L and the standard 4 spd auto. Diesel here is only about 25 cents more than unleaded, but in looking at the cost differential with adding the Dmax/Allison to the package I figured I would have to drive 65,000 miles just to break even. I simply don't drive the truck that much. It's not a commuter; it's used to haul hay, firewood, stone, and to plow my driveway in the winter. About four times a year I need to move a 6600# mini excavator about 20 miles; with the trailer that's about 9000# total and the 6.0 handles it just fine.

Unless you're swimming in cash, the choice really comes down to how much you need the extra pulling power of the DMax. For me, it just didn't make financial sense.

Good luck! Pete

k3500CC8.1 · September 13, 2006

Just a few thoughts on the diesel vs. gas subject..

I get a kick out of the diesel guys and how they talk about the duramax being an almost religious experience. I've owned them both and went back to the 8100 due to its balance of performance and simplicity.

Here's a few remarks on the different web sites that brings a smile.

That big block pulled like a V-6...

the 8100 burns 3 quarts of oil every 3000 miles...

I pulled 31000lbs up a 7% grade at 80mph with my duramax..

You need pulling power, get the diesel. 8100 is for lighter loads...

The GM big block is known for its realibility problems..

The 8100 is a 100,000 mile throw away engine..

That 8100 engine will get 7mpg loaded or unloaded..

I raced a Corvette last night with my stock Duramax, and almost won...

I got 27mpg out of my Duramax on the last tank..

the 8100 is gutless...

You'll get more on resale return than you paid for the diesel option..

You'll easily double your mileage with the diesel over the gas..

Now the last time I checked, the 8100 engine is available in Chevrolet Meduim Duty Trucks up to Class 7 and 37,600lbs.. The Duramax 6600 (Not the Duramax 7800) is available up to Class 5 and 26,000lbs...????? Pulls like a V-6??? Gutless??? If you have extreme towing needs, get the Duramax and don't bother with the gas engine??? Seems that the GM powertrain engineers have more faith in the 8100 than the Duramax 6600... So do I... And it's the only gas engine available in Class 7 Trucks..

I've owned 3 Vortec 454's and two 8100's and the most oil that any of them ever burned was 1.5 quarts per 3000 miles, and that was only the 98 C3500 I owned.. On average the big blocks I've owned burn about 1 quart per 3000 miles..

For those who say that my friends 8100 gets 7-8mpg loaded or unloaded do not understand the laws of physics... The guys saying the are getting 27mpg out of the Duramax do not understand math.. I did get 21mpg out of my K3500 if I drove it at 64mph, no stops, cool weather, and zero headwind.. Basically, I was a danger to the traffic flow trying to acheive those numbers.. I have frequently returned 14-15 mpg out of the 8100's on long trips and driving the speed limit..

The 2003 Duramax I owned was a great truck. It was sluggish off the line like every other diesel I've drove. You mash the throttle and wait a couple seconds for the power to build.. I hate that dead peddle feel, but you'll never here a peep out of the diesel guys about it.. You'll also never here about paying almost an extra $6K for basically a 1300 rpm operating range.. My 2003 K3500 wasn't a hot rod either stock, it had trouble keeping up with honda civics, and got smoked a couple of times by a Titan. Now programed it's was a different story but the extra power comes with negitive impact on a nearly $40K investment. The 2006 Duramax's I drove still had the dead peadle, had to wait for power to build, but ran great once you got moving down the road. Did they throw me back in the seat?? No.... Would I want to go out and start picking on sports cars?? No... Is it a factory hot rod?? No... Is it a great work truck that's perfect for some using the truck heavily everyday and needs maxium mileage for bigger profits??? Absolutely.. Will it flat out tow and disgrace a 8100 when they are both pulling 16,000lbs trailers.. Not a chance...The story here is more than torque, it also includes gearing, and available rpm in each gear. That's why GM is able to but the 8100 in Class 7 Trucks.

I love it when you hear guys talking about resale value.. Of course you're going to get more for a diesel truck than a gas, but you also paid a butt load more of money for it.. I do not know of any dealers or private parties that will get an extra $6K plus for a equally equipped duramax truck over an equally equipped 8100 truck. I bet you'll be lucky to break the $4k mark, which would be a negative return for the diesel choice. Is it easier to sell an used Duramax over an used 8100. Yes.. Would I buy an used Duramax that is out of warrenty?? Not a chance... Just look at the replacement cost of the fuel system components alone on the Duramax... Would I have a problem buying an 8100 truck that has been well maintained and has been out of warrenty for 60K miles?? No problem here.. Plus almost every shade tree mechanic out there can work on the engine or get the parts down at the local parts store without needing a loan..

I think it basically comes down to how much you drive the truck and how often you pull with it.. If its an almost daily driver or pull frequently with it, diesel is the choice because of fuel mileage... Not because of the so-called "ultimate" pulling power of the diesel.. I think a majority of the diesel buyers out there are trying to keep up with the Jones and chose the diesel for more symbolic/macho reasons..Maybe not, but thats my opinion..

With the introduction of the new 100,000 mile powertrain warrenty for GM vehicles, the decision line becomes much more blurred.. It will be interesting to see if GM steps up to the plate and backs the diesel for 200,000 miles. I bet they don't, especially with the new EPA engine coming out. This will speak volumes if GM keeps the same warrenty coverage for both the 8100 and Duramax engines..

Just a few thought to chew on..

redvett · September 13, 2006

With the cost of the 2007 diesels with the new emissions comes and additional $1500 - $2000 increase with the optiol of the $6000 for the diesel and a 10 cent increase in low sulphur fuel and a 1 mpg decrease in fuel economy the diesel for most people wont be an option. The new low emission 2007 models wont be available until early in 2007.

The cost for a diesel and limited or occasional towing it does not make sense dollar wise.

c502cid · September 14, 2006

Pretty funny stuff, I've heard the stinky fuel guys say lots of those same things. Now my buddy just bought a diesel and he's the only one I know telling the truth about it. Mind you he loves it, and it is a very cool engine, but he is still not all that thrilled with the mileage and the performance.

I'm still waiting for any kind of confirmation on the 496 being available in the new GMT 900 HD's. If I cant get it, I might just keep my old truck a few more years.

k3500CC8.1 · September 14, 2006

Need to make a correction about the medium duty stuff. The 8100 is available in C8500's up to 42,600lbs GVW. No Duramax 6600's found in those weight ranges.... Ummmmmm....... Way past the Class 5 26,000lbs stuff the 6600 hangs around in.... At that GVW, your playing with the Cat C7 boys...

Just something else to think about....

Big Al · September 15, 2006

Big Al -- I had to make the same choice and ended up with a 6L and the standard 4 spd auto. Diesel here is only about 25 cents more than unleaded, but in looking at the cost differential with adding the Dmax/Allison to the package I figured I would have to drive 65,000 miles just to break even. I simply don't drive the truck that much. It's not a commuter; it's used to haul hay, firewood, stone, and to plow my driveway in the winter. About four times a year I need to move a 6600# mini excavator about 20 miles; with the trailer that's about 9000# total and the 6.0 handles it just fine.

Unless you're swimming in cash, the choice really comes down to how much you need the extra pulling power of the DMax. For me, it just didn't make financial sense.

Good luck! Pete

<{POST_SNAPBACK}>

Thanks for the advice. I know that the 6.0L has pretty good power with the 4-speed trani and 4.10 rear end. I was thinking that the new 6.2 or a revised 8.1 with the 6-speed allison trani and a 3.73 rear end would be better and result in better gas mileage.

ChrisNJ · September 22, 2006

k3500cc8.1: that is the best diesel vs. 8.1 thread i've seen. i have the same opinion as you. we are the minority. i own a 6.0 and an 8.1. i drove a freinds dmax, and it just wasn't the same as my 8.1, i couldn't tell why, but you nailed it. off the line the 8.1 pulls like a freight train, and while the dmax has much better numbers, it just didn't feel like it. i want the 8.1 in my next 07 truck. my wife and i fight to drive the 8.1 over my 6.0, and my 4.6L caddy. however, if i were towing for a living on the open road, i think the dmax would be the better choice. however my 8.1 just needs to be a daily driver for 340 day and tow a 10K trailer for the other 25 days. hands down the 8.1 is a pleasure compare to my 6.0. i like my 6.0 too, just not towing big with it. i don't care much about mpg either, so again i am in the minority, safety in a big truck here on route 80 in NJ where people are dieing every 1-2 weeks is paramount to me for my family. long live the big gassers!!!!

davefr · September 26, 2006

The diesel gang seems to be somewhat of a brainwashed cult.

Time are changing:

- The LMM Duramax will likely be about a $10k option

- Diesel's about $.50/gal higher then gas

- ULSD diesel is reported as giving lower MPG then "old" diesel

- Diesel's are undergoing an evolution of new "unproven" emission controls.

I've driven Duramax's and they're wonderful highway performers but they sure seem like slugs in everyday driving. You have to floor them to get them moving.

I sure hope the 8.1 comes back in '07 and I hope rumors of an output increase are true.

Big Al · September 29, 2006

The diesel gang seems to be somewhat of a brainwashed cult.

Time are changing:

- The LMM Duramax will likely be about a $10k option

- Diesel's about $.50/gal higher then gas

- ULSD diesel is reported as giving lower MPG then "old" diesel

- Diesel's are undergoing an evolution of new "unproven" emission controls.

I've driven Duramax's and they're wonderful highway performers but they sure seem like slugs in everyday driving. You have to floor them to get them moving.

I sure hope the 8.1 comes back in '07 and I hope rumors of an output increase are true.

<{POST_SNAPBACK}>

I agree and had decided to go with the HD with the 8.1L since I'm not a full time tower and can't justify the diesel. If it's not offered, what are my options? Is the new super duty Ford with the 6.8L and TorqueShift trani a better option than the GMC 6.0L with a four-speed auto? Please GM, reconsider!

BenJammin53 · October 1, 2006

The press release says the '07 HD's with the 6.0L will have a 6L90 6 speed auto. I haven't seen any gear ratios for it so I don't know about it. I don't know what the Ford with the V10 is like, but I haven't heard any complaints.

Another thing that I haven't seen any mention of was a manual transmission.

It sounds to me like GM is shooting themselves in the foot with the new HD's. I would hope that later on down the line there will be some sort of big cube gasser, but with Dodge only offering the 5.7 for a gas engine I'm not too hopeful.

ChrisNJ · October 1, 2006

boy, 3 more people died on rt. 80 here (NJ) over the weekend. that's about 10-15 since june. in 15 years i've been driving rt. 80 in jersey, it has gone from 1-2 deaths per year to huge numbers this year. people are just flying, talking on their phones, text messaging, freekin NUTS. now i REALLY want to trade my 02 sierra and my caddy for a new truck, but they just aren;t making one for me. How bout the 6.2-VVT in the 1500 CC to boost the tow rating?!?!?!? I can be pursuaded to try it.