Much greater load carrying capacity,
Higher stability (lots of sidewall means less flex)
Greater safety (if you suffer a rear blowout you still have round rubber on the road)
At tire change time you get to buy 6 vs. 4
With custom wheels tire rotation becomes a real drag
Changing tire size becomes more problematic.
Rear tire wear becomes a factor if you do a lot of in town (lots of turns wears the crap out of the wide tire set)
That bubble butt is harder to get into parking slots
You have to learn to take corners a bit wider (or risk buying a new tire due to a trashed sidewall)
As stated b4 a bit of a mileage hit.
Looks (different strokes for different folks)
I used to think duallies were the most hideous things I'd ever seen, but as I'm now looking for a tow vehicle, the look is growing on me! haha!
As for narrow garages - the length alone would prohibit me from parking it in my garage. I just have to see if I leave it parked in my driveway if I can get my other car by it! I was talking to some neighbors this weekend, and we were all complaining about our narrow driveways and small garages....
Love, love, love my duallies!! Hubby and I each have one - one gas, one diesel. The only real drawbacks as others have mentioned are parking and drive-thrus. They do fit through the bank drive-thrus, but I have to watch the tires in my side mirrors. There is literally about 1/2" of clearance on each side. I just use the outside lane when possible . I can't go through Tim Horton's though, it's just too narrow .
Oh yeah, the biggest drawback to my truck is the fact that the 454 engine only gets about 5 mpg in town and 12 hwy . It stayed parked until just recently.
Lapeer ... a small drinking town with a farming problem.
Proud Closet Canterer!
My friend has one and she wouldn't tow her horse trailer without it. (it actually does stay connected to the 5-horse slant) She's usually hauling 3 or more horses and loves the stability and braking capacity. Cons - uses more fuel and tires.
You need a dually for stability if you are pulling a very large, heavy trailer. If you are not pulling a very large, heavy trailer, go for a SRW. A dually is more expensive to maintain and a PITA to drive around town.
I pull my 3H, which is 7' wide/20' on the floor and 5k# empty (sometimes up to 9500 loaded), with an F-250 7.3L diesel, which is obviously a SRW. I drag that trailer all over creation, with great stability, maneuverability, and most importantly, excellent stopping power. My friend has a beast of a 4H, 8' wide/25' on the floor with a LQ, close to 10k# empty, and she really needs her dually. She'd rather have a SRW, but it couldn't handle that big trailer.
It's certainly possible to have too much engine for the load, but I've only had that problem with unloaded 18 wheeler cabs and unloaded dump trucks. Anything pickup-like should behave decently when towing some weight.
27 years of driving quad cab duallys and I went to a single cab 4 wheel truck. Why? Fuel economy. I miss the back seat. I miss the tow options. I do not miss the horrendous in town parking difficulties. The plan ahead before you drive anywhere parking plans. The 5 - 8 mpg. IF I should ever get one again it will be a diesel, ton and a quarter extended - not crew - cab.
"If you don't know where you are going, any road will take you there"
"Get a diesel and you won't have a MPG problem compared to gas duallies. Couldn't give me one of them..... "
Depends on how much you drive. Diesel is much pricier than gas, and are more expensive to both buy and maintain. My son thought it over real hard before buying a big Chevy dually. Start it up, drive away, quiet, smooth, no diesel odor, 10 MPG pulling his huge box trailer. He got the huge 8 liter motor and it would pull a train. But he's not planning on using it much, and diesels make up the difference if you are going to knock out some serious miles. As for the dually advantage, mostly the road holding ability as sway is a thing of the past.
I tow a 4 horse Featherlite Slant. 7' wide, 4400 pounds empty, about 9500 or a hair more loaded. My truck handles the weight fine. Breaking, turning, no swaying, etc. And I've driven it from PA to VA several times fully loaded.
I like the duallys and would get one if it wasn't to be my primary vehicle. I have enough trouble finding parking spaces to accomodate my crew cab short bed truck without having duallys, as well.