Tow vehicle
Art,
This is a pretty hot topic on a lot of RV BBS's, towing with SUV's...
The Navigator is the "kissin cousin" of the Ford Expy, basically an upscale Expedition... The wheelbase of this vehicle (116")is pretty short to be towing a 25-27' TT...
There is a rule of thumb in towing that states: For the first 20' of trailer, the tow vehicle wheelbase should be 113" MINIMUM, then for each additional foot of trailer, add 4" to the tow vehicle wheelbase... Using this formula, for a 25' TT your wheelbase should be 123" MINIMUM, for a 27' TT it should be 141" MINIMUM...
The problem with towing with short wheelbase vehicles is the tendency of the "tail to wag the dog", in other words trailer sway effecting stability of the tow vehicle...
I tow a 27' TT and it weighs in at #6400+ pounds when fully loaded... There is a lot of frontal and side area to this trailer and it requires a substantial tow vehicle with a good wheelbase... My tow vehicle is a Ford F-250 SuperDuty pickup truck, 4X4 OffRoad with 142" wheelbase and V10 motor with 3:73 rear axle... The truck weighs #7650 when fully loaded!!! It's a also a good rule to have your tow vehicle heavier than the TT...
The 5.4L motor is a good engine but could be marginal towing a trailer of any size... The 5.4L equates to 330 cubic inches which in my opinion is right on the edge for towing moderately large trailers... Remember, when towing at altitude a normally aspirated motor (non-turbo diesel) will lose 2-4% of it's power per 1000' of altitude... Thus at 10,000' your towing performance could be down as much as 20-40%...
In general, SUV's have short wheel bases, high center of gravity, soft suspensions, and P-Series Tires... ALL of these will contribute to trailer sway and instability...
Having said all this, there are people towing with Expeditions, Navigators and the like... If you are going to tow a trailer of this size, I would SERIOUSLY recommend you look at purchasing either the Hensley Arrow or Pullrite hitch... These are the two best anti sway hitches on the market today and will certainly add to your towing safety and success... Both of these hitches come at a pretty high price... The Hensley is around $2700 and the Pullrite is about $2000... However, they WILL do the job... I personally tow with a Pullrite (#10,000 version) and it is "rock solid stability" under most all conditions...
Finally, remember that SUV's like the Expy and Navigator are essentially 1/2 ton trucks... Their GVWR is usually around #6600... Half ton trucks will also have correspondingly smaller brakes and suspension than their 3/4 or 1 ton cousins... Moving the load forward is only one aspect of towing... Controlling the load and STOPPING the load are argueably the more important part of towing...
When calculating GVWR of your Navigator, include a full fuel load, all passengers, all cargo carried in the truck and the hitch weight and the tongue weight of the trailer... Tongue weights of the a 27 footer can be susbstantial, especially with front kitchen models... My 27' Nomad front kitchen has a tongue weight of just over #800...
All in all, I am not a proponent of towing with SUV's and Mini Vans... You can do it if properly setup, but in my opinion, performance and safety are not what they should be...
With the short wheelbase, soft suspension, P-Series tires and relatively small motor, there is no room for error in hitch setup or towing scenarios... In my opinion, a Hensley or Pullrite is mandatory on these types of vehicles...
Sorry to be so negative but that is pretty much the facts on the Navigator when used for towing... I know what their towing specs say but if I were you, I would take them with "a grain of salt"... Experienced towers will derate maximum ratings by 10-25% and I am personally towing at 64% of my maximum and wouldn't want to go much higher than that with this truck...
I would tow no more than #5000 (loaded weight) with the Navigator and would try to keep the length of the TT around 20-22' maximum... For a TT of longer length, I recommend you go to a full size pickup (or Ford Excursion) with a decent wheelbase and good size motor...
Best Regards,
Les
2000 Ford F-250 Super Duty, XLT SuperCab, 4X4 Off Road, SWB, V10/3:73LS/4R100 towing 1999 Skyline 27' Nomad, Model 2700, Pullrite Hitch, Jordan Ultima 2020 brake conttroller