Towing a 4,000lb folding trailer at high elevation

[PacificGroveRover]

I have purchased a very large folding trailer that can weigh close to 4,000lbs when loaded. My hunch is that my 99 DII will struggle in the Sierras at high elevation. Anybody have any first hand experience towing a heavy trailer with a DII?atriot:

 

[justinhaaga]

the problem is stopping. make sure the trailer has brakes.

 

[pjkbrit]

the problem is stopping. make sure the trailer has brakes.

X2
I have a great utility trailer (but unbraked) and filled with a yard of rocks my Disco really has no problem with the pulling...but I would not be happy trailering this load without brakes on the trailer for any distance, (the yard is only 2 miles through my local town). I've also picked up 3 Ebay car purchases with it and a U-haul 4 wheel trailer which is a great set up....and get this...I always get 14-15 mpg even with this load on the highway.

 

[k12]

It's my understanding that vehicles with electronic control modules regulating the air-fuel ratio are not effected by altitude, unlike carberated motors, which are dogs at elevation if not jetted for it. My carberated 89 yj sucks at 7k plus. I have yet to have the pleasure of taking either of my discos (both DI's) to elevation, but will this summer when we move to CO!

The brakes ideas are right on.

Good luck.

 

[Surf]

They are definately affected by altitude. Unless you are using some type of forced induction system, you will lose power.

 

[k12]

Yeah, but not nearly as much as with carberation. With efi and ecm, the computer, with the help of the map sensor, can adjust the air/fuel ratio to achieve the ideal 14.7/1 ratio, whereas with a carburator, the ratio is set by the jets and your altitude at that time and is not adjustable automatically. Of course greater altitude equals less oxygen, and therefore, less potential power, but at least with efi, its not as nearly as bad due to the computer's ability to regulate the fuel/air ratio.

Although only anectotal evidence, I had to floor the 89 jeep in second gear many times to make it up to the alpine visitor center in rocky mountain national park (approx. 11.7k), whereas more modern vehicles with efi were simply cruising on up.