Looking at the maintenance schedules for a 2020 Durango and some items are really long now . First coolant replacement is 10 years or 150000 miles . Serpentine belt is 15 years or 150000 miles. Also it says the transmission fluid is good for the life of the vehicle in the ZF 8 speed transmission . This is for the Pentastar V6 , the V8’s are a little more stringent . Just found these couple of items eye opening . Also I think they have to simplify some of these cars , the stupid manual is now over 700 pages long .
Are you sure its the serpentine belt…to me its probably the timing belt in case yours has one instead of a timing chain.
The manuals have been lengthy for years , nothing new there.
The Pentastar V6 (as well as the Hemi V8) having timing chains. So the OP’s serpentine belt may have 15 year/150k mile replacement intervals. However, it is unusual for that item to a stated replacement interval.
I’ve seen some maintenance schedules where it very specifically says to change the accessory drive belt . . . aka the serpentine belt . . . at 150K
I can’t imagine any manufacturer saying it’s okay to leave the timing belt in there for 15yrs/150K
In the past, I’ve found that the serpentine belt was best replaced when it stretched enough to make it difficult to get off and on. The belt still looked good, but had stretched enough that removal was difficult without resetting the ratchet. Maybe newer belt materials don’t stretch as quickly as the older ones, and the recommendation is reasonable.
I don’t remember how long the manual was for my 59 bug but not very long. It did have some useful driving tips in it though that I still remember. One was to save on brake wear, don’t brake while making a turn. I don’t know why but 50 years later, every time I turn and brake, I think about excessive wear on my pads.
wow!
somebody finally included PCV valve replacement into a routine maintenance! 
Toyota’s been doing that for quite awhile now . . . to mention just one manufacturer
the newest (and only) Toyota I own is 2005 vintage… not there yet
The engineers have definitely figured out how to make engines require less frequent service. That’s the good news. The bad news is that the manufacturer has an incentive to recommend infrequent service. The potential customer often has access to “total cost to own” data for the vehicle, and that will be lower if infrequent servicing is recommended. Being aware of the conflict of interest, a new car buyer might want to error on the side of servicing intervals more frequent than the owners manual suggests.
Dexcool has been good for 10 years for quite some time now.
Many carmakers now say transmission fluid is good for the life of the vehicle. I agree, provided you expect the life of the vehicle to be about 150,000 miles. So I still recommend trans fluid every 60,000 miles. Your 8 speed trans requires a very specific fluid though, keep that in mind.
Serpentine belts are better than they used to be, as are all rubber things under the hood. When I started in this business shops all had radiator hoses in stock and not a week went by that we didn’t have a car towed in with a blown hose. Now I don’t even have a recommended interval for hose replacement.
I have never found a serpentine belt hard to remove. Since they are not going back on, I just cut them.
Yeah thats very true, have a 2008 Ascender (GMC Envoy) and it still has the original hoses on it and it has 150000 miles on it. I have them check it every oil change and they say they are fine . Yes the ZF 8 speed auto does take specific fluid which is pretty pricey from what i have read , maybe it will be a little cheaper in 10 years when I have to think about it .