I have been using my '05 OR to occasionally tow my racecar for about a year now without any problems. I am going to run an entire race season this year though, and I'm afraid that might be a little much for the X. I pull a 2700lb Porsche 944 on a 1200lb trailer with a few sets of wheels (probably another 250lb). So add 300lb for the tools and stuff I put in the racecar and that's roughly 4500lb. I know it's within the limit but the rear suspension rides awfully low and I wonder if towing close to the limit frequently is going to considerably shorten the life of the drivetrain. So, thoughts? Is there anything I can do to beef up the towing capacity? It's a 6-speed so a trans cooler isn't really an option. The other option is to sell and buy a bigger truck. It's an '05 Night Armor OR 55k miles with every conceivable option (XM radio, tow pkg, airbag pkg, RF stereo, etc) just in case anyone is in the market.

You can go with an aal or have a heavier leaf pack made up.

The towing capacity is what it is - unless you get a longer wheelbase and a larger engine. That being said, an AAL or heavy-duty replacement leaf pack will help with the rear end sagging.

Thanks. That's perfect actually. The Calmini kit is only $150 so I'm going to order it tomorrow. I suppose I'm trying to increase reliability more so than towing capacity. Like I said, the weight I'm pulling is less than the rated capacity. I just want to improve the sagging rear and avoid prematurely wearing out the suspension and drivetrain (which may be unavoidable).
Thanks again.

You might also want to add a load leveling trailer hitch. You can buy a good one from most travel trailer dealers. I have one for when I tow my travel trailer. It works great, but I was more than a little disappointed with the rear suspension and added an AAL to my truck. This made the truck ride a whole lot better even when empty.

I bought a load levelling trailer hitch for my Xterra. It made an incedible difference. We are pulling a 2900 lb travel trailer, with a 300 lb tongue load. With the springbars of the load leveling hitch the rear of the Xterra rides level, so stress on the back end is minimized.

I am having a problem with my trailer signal lights though. The RV guy who installed them thinks he did everythign right.

Anyone have any idea?

@Ted_C: I searched on this topic last week and found a lot of helpful posts. Basically there are some additional relay's needed to let the trailer lights work properly. There was some debate I found whether the 4pin plug needed a relay or just the 7pin. If you do a quick search of the forums you'll find a lot more info.

I believe the second gen X's require 2-3 relays and pigtails to make the lights work. get the kit from Nissan. They'll know.