Duramax vs. big-block gasser?

BlackSilver · March 17, 2002

Going to upgrade my Silverado to a new 2500 LT extended cab for better safety pulling an RV. The RV pulling will be 10% of the time, otherwise it will be a daily driver.

I will go with either the 8.1L gasser or the Duramax, plus the Allison tranny.

I've 'justified' the extra money for the Allison transmission, but $5K extra for the DuraMax seems out of line with my needs.

Anyone out there who has run both of these Chev engines and can give me an objective comparison?

Thanks

Shaners · March 17, 2002

I moved this to the HD forum so you could get some responses from the "big guys".

tinman · March 17, 2002

I had this exel spread sheet showing the pay back on a diesel . The was I saw it it took around 70000 miles to pay for the cost of the d-max. I will try and find the exel file send it to you or post it .

Shaners · March 17, 2002

How heavy is the RV? The Dmax should pull it better than the 8.1L, but the 8.1L is no slouch by any means.

You will see better fuel efficiancy with the DMax towing and unladen. That helps some, even though diesel is more expensive than gasoline right now.

You have to keep in mind that the Dmax is sort of an investment. I can almost guarantee the Dmax with 100K miles on it, will be worth about $2500 more than the 8.1L with the same amount of miles.

antig24 · March 17, 2002

Yep, there's a lot of things to think about, unless ur rv is huge, the big block will do fine pulling it if you only tow 10% of the time u use your truck. It also depends on how long u plan to keep the truck. The dmax has a lot more upfront cost but in the longrun it'll pay off eventually.

regcab02HD · March 17, 2002

It only takes 70,000 miles for the Dmax to pay for itself over the 8.1. Man, I thought it took like 250,000 miles.

What prices on the fuel did you use?

I wish you woulda told me that about 4 months ago.

bluenote · March 17, 2002

In my area, diesel is less than gas right now. In Michigan, I would say that over the course of the year, diesel and gas average about the same cost. It's just that the change up and down for diesel prices tends to lag a few weeks behind gas. Maybe other areas of the country are quite different?? I figured right around 70,000 miles myself, just with paper and a calculator, to cover the cost of the duramax over the 8.1 big block. A lot of people will claim higher maintenance costs, such as more expensive oil changes, but most routine maintenance is less frequent with the diesel, so a lot of that equals out. I know people with the big block that love it, and I know the duramax is great too. I don't think you can go wrong either way...they'll both pull like demons. You will almost definitely get more for trade-in with the duramax too (unless your heads warp and melt ). Go to the bluebook site and they've already got approximate values for used 8.1's and dmax's. www.kbb.com

Jpshostr · March 17, 2002

If you are buying the truck for the sole purpose of towing, go diesel. You get the mileage benefits that help offset the higher initial cost, plus come trade in time that diesel option will still add on 75-80% of what it cost new to the value of the truck. Now since you are pulling only 10% of the time, that complicates things a bit. Diesel would be great towing, but for short daily drives they aren't the best. Starting, driving a few miles to work, sitting all day, then driving home are rough on them. Shaners will tell you how he rough his gas is with his short commutes, a diesel would even be worse as they need to get up to proper operating temperature, that just doesn't happen.

My suggestion:

Short daily drives, go gas. Fairly decent drives, diesel will suit you fine.

BlackSilver · March 17, 2002

How heavy is the RV? The Dmax should pull it better than the 8.1L, but the 8.1L is no slouch by any means.

You will see better fuel efficiancy with the DMax towing and unladen. That helps some, even though diesel is more expensive than gasoline right now.

You have to keep in mind that the Dmax is sort of an investment. I can almost guarantee the Dmax with 100K miles on it, will be worth about $2500 more than the 8.1L with the same amount of miles.

The RV weighs 6400# dry, perhaps 8000# fully loaded to travel.

Jpshostr · March 17, 2002

The RV weighs 6400# dry, perhaps 8000# fully loaded to travel.

Shucks, with just that much weight either of these motors will pull it around like its not even hooked up. With either choice you sure won't be going wrong from a pulling standpoint.

Shaners · March 17, 2002

Jp is right.... both motors will pull your RV just fine.... I have the 6.0L in my truck and my RV weighs in at about 8000 lbs. I only tow a few times a year so the 6.0L is OK for me.

If the Dmax sounded like a Powerstroke or Cummins, then in your case I would definatly get the 8.1L. But the Dmax is sooo quiet....... and it could pay for itself. It's a tough decision especially when you are financing because the Dmax is about $75 more a month in payments.

BlackSilver · March 17, 2002

Jp is right.... both motors will pull your RV just fine....

OK, one other issue......

In mountain grades the gas engine (especially with the smarts in the Allison tranny) will provide some "engine braking" on downgrades, good for keeping brakes cooler.

I've heard that diesels do not give that braking effect????

Shaners · March 17, 2002

OK, one other issue......

In mountain grades the gas engine (especially with the smarts in the Allison tranny) will provide some "engine braking" on downgrades, good for keeping brakes cooler.

I've heard that diesels do not give that braking effect????

These engines and trannies are so computer controlled now that I think the Allison will take care of all your needs.

My retired boss bought a '35 Travel Supreme and a crewcab 4x4 Dmax 3500 last fall and headed across the country. I can't wait to see him in the spring when he gets back to hear his impressions!!!

JEBar · March 17, 2002

Have had both and currently own an '02 3500 crewcab Duramax/Allison .... In considering the switch to diesel it would appear wise to look at your overall vehicle use. No doubt that both of the ones mentioned will pull the camper listed. In my case I doubt that I pull anything 10% of the time but when I do it can be for hundreds, if not thousands of miles straight. Example: Once a year, during a two week period, pulling a heavy 26' boat from NC to SD which runs 3000+ miles. Also have a tractor which has been on a trailer four times since October of '01, two of those trips were 300+ miles one way. I live just over 20 miles from work and for me that was the kicker which lead me to try the Duramax ... if I lived only a few miles away I might have chosen the gasoline engine. I have seen data which suggest that the payback period on the Duramax runs 50,000 to 70,000 miles (depending on a multitude of factors). All I can say is that I've been driving trucks since the early '60's and this is the best truck I have ever owned. I find it difficult to believe I could be any more pleased with anyother vehicle.

bluenote · March 17, 2002

I agree with jebar...this is the best vehicle I've ever owned. I also drive 20+ miles to work, so the diesel gets warmed up during my drive. I was worried about not getting enough cab heat in the winter, but that hasn't been a problem. In fact, I haven't even installed the grill and bumper covers that come with the duramax. Maybe in extreme cold, it would be an issue, but above 0 fareinheit has been no problems. I can't run the heat on high too long, or it sweats you out.

blacksilver - The duramax/allison combo certainly does have the grade-braking feature. It's a function of the tranny, so it works with any allison-equipped truck. I haven't had the chance to see how it works in the mountains yet, but I know that in tow/haul mode, I can nearly stop my truck/5er team in a little over a quarter mile, without the brakes. I pull a couple thousand pounds more than what you're talking about, so I know you would see the benefits of the grade-braking.