For a towing application, you can't beat the Cummins. They are also easy to add a little horse power by using a plug and play module or a downloader. Also the towing mileage is usually a little higher than the D-Max.
One place the D-Max has the edge is the automatic tranny. It will hold up better with added horsepower. The Dodge trannies are only good for around a75 HP increase above stock to be reliable. My 03 with a 47re automatic held up for a while. But with my 500 hp and 1020 tq at the rear wheels I had to upgrade mine with a Goerend Bros.
Comes down to your personal preference. We can usually make our own arguments to make our favorite choice better.

Randy

Cummins. If you need the space, get a mega cab to have the best of both worlds. The mega cabs look goofy stock, but lifted they look pretty sick. They just feel like more solid of a truck than Chevy trucks do.

I have a 24' enclosed to pull my race car in, and I may be looking ofr a new truck here soon....


well there are 6 of us that race and i am a chevy guy the rest of em have power strokes and one of em has a ext 2wd cummins like a 96 model i believe well i think its edge he has on it and stright pipe his truck pulling a 28ft enclosed trailer with too rail cars ,when we are pulling the mtn we all live on he gives us a head start lol and he will come by everyone of us patting the pedal at us.. and i think if i upgrade too bigger truck i going with a cummins

Well of course the dodge can beat powerjokes, :lol:

well yea i know that cant stand ford trying tell them and they wanna :punch: about who can pull more i tell let go get my 4wd tractor and hook up too the power strokes. but i was just using that as a reference with tommie's cummins

Ya, last summer I worked delivering tractors and other farm equipment with a 03 powerstroke. It sucked. Didn't pull well and got terrible fuel mileage. I'd come home and get in my dads 03 Dmax with his 37' 5th wheel and just a 50hp tow tune I did with EFILive and HUGE difference over the PS and a MUCH more comfortable truck to ride in, not to mention, got much better mileage.

now know last yea a dmax 4dr dually dunno wat was done too it but he was pulling 37 ft. 5th wheel cattle trailer and out ran 2 cops up that same mtn. thats what i haerd for months but dunno how true that be if it is then thatd be sweet towin and still out running them lol:chug:

I have had both and 7.3 powerstrokes. I would by far recommend the Cummins. Power is ungodly and they get fantastic fuel mileage.

I own an 07 5.9l cummins. I would really like to know what years you are looking at, brand new 07.5 and newer on both models I cant speak for.

Lets say 04-07 for dodge and I think 06 when chevy got the LBZ. Both are close in numbers stock.
dodge....
-35"s bone stock
-untouched motor for YEARS, everyone will admit the 5.9l cummins is a beast and will last forever
-I think it was 05 they interrior of dodge appealed better to me
-4 dr is cramped in the back but mega cab is NOT!
-I honestly am still suprised a year later at how well my 07 5.9l drives down the road pulling 7-8klbs or unloaded, it
it takes turns with loads and unloaded awesome and the ride is a dream.
-It does drive better with the bigger tires then the small donuts that come stock.
-The paint on dodges is not as good as chevys.
-I like chevys dashes better (layout). Dodge does have the input jack for Ipods tho, idk bout chevy.
-power is endless
-trannys not as good as chevy

Chevy.....
-duramax good motor
-allison good tranny
-4dr is cramped IMO,
-chevy I think are more expensive with higher resale value, but dont know FOR SURE
-never drove a HD with a load, only ridden. Ride was good, I dont think as good as my mega cab tho.
-I dont like the IFS sus instead of SFA. The SFA on dodge is very impressive with how good they got it to handle and drive


I think overall it may just come to what you find on a used lot or w.e your circumstances may be. Maybe a color you find with the interior package you like. But I love my dodge, the way it pulls, drives, handles, and gets great MPG. I do believe in the years I mentioned stock for stock the dodge will get the better MPG. I do know that if your wanting to just through massive programmers at both trucks the chevy will do better with just "bolt-ons" without having to touch the tranny. But the dodge with a smarty or smarty jr. programmer is very impressive!

The cummins world is similair to the 1500 gen 3 and newer chevy 1/2 ton aftermarket world, it is endless. With alot fo support out their to help.

If you have any questions i will probably respond faster email, carmel1503@yahoo.com

i dont kno much about diesels. my dad has an 06 duramax. very confterble and looks better IMO. but here in texas the cummin is very well respected.